Bluetooth Low Energy, through the Generic Attribute Profile (GATT), supports various ways to send and receive data between clients and servers. Data can be transmitted through indications, notifications, write requests and read requests. Data can also be transmitted through the Generic Access Profile (GAP) by using broadcasts. Here however, I'll focus on write and read requests. Write and read requests are made by a client to a server, to ask for data (read request) or to send data (write request). In these cases, the client first makes the request, and the server then responds, by either acknowledging the write request (and thus, writing the data) or by sending back the value requested by the client. To be able to make write and read requests, we must first understand how BLE handles the data it transmits. To transmit data back and forth between devices, BLE uses the GATT protocol. The GATT protocol handles data using a GATT database. A GATT database implements profiles, and each profile is made from a collection of services. These services each contain one or more characteristics. A BLE characteristic is made of attributes. These attributes constitute the data itself, and the handle to reference, access or modify said data. To have a characteristic that is able to be both written and read, it must be first created. This is done precisely in the GATT database file ( gatt_db.h 😞 /* gatt_db.h */ /* Custom service*/ PRIMARY_SERVICE_UUID128(service_custom, uuid_custom_service)     /* Custom characteristic with read and write properties */     CHARACTERISTIC_UUID128(char_custom, uuid_custom_char, (gGattCharPropRead_c | gGattCharPropWrite_c))         /* Custom length attribute with read and write permissions*/         VALUE_UUID128_VARLEN(value_custom, uuid_custom_char, (gPermissionFlagReadable_c | gPermissionFlagWritable_c), 50, 1, 0x00) The custom UUIDs are defined in the gatt_uuid128.h file: /* gatt_uuid128.h */ /* Custom 128 bit UUIDs*/ UUID128(uuid_custom_service, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x00, 0x01, 0xFF, 0x01) UUID128(uuid_custom_char, 0xA1, 0xB2, 0xC3, 0xD4, 0xE5, 0xF6, 0x17, 0x28, 0x39, 0x4A, 0x5B, 0x6C, 0x7D, 0x8E, 0x9F, 0x00) With this custom characteristic, we can write and read a value of up to 50 bytes (as defined by the variable length value declared in the gatt_db.h file, see code above). Remember that you also need to implement the interface and functions for the service. For further information and guidance in how to make a custom profile, please refer to the BLE application developer's guide (BLEDAG.pdf, located in <KW40Z_connSw_install_dir>\ConnSw\doc\BLEADG.pdf. Once a connection has been made, and you've got two (or more) devices connected, read and write requests can be made. I'll first cover how to make a write and read request from the client side, then from the server side. Client To make a write request to a server, you'll need to have the handle for the characteristic you want to modify. This handle should be stored once the characteristic discovery is done. Obviously, you also need the data that is going to be written. The following function needs a pointer to the data and the size of the data. It also uses the handle to tell the server what characteristic is going to be written: static void SendWriteReq(uint8_t* data, uint8_t dataSize) {       gattCharacteristic_t characteristic;     characteristic.value.handle = charHandle;     // Previously stored characteristic handle     GattClient_WriteCharacteristicValue( mPeerInformation.deviceId, &characteristic,                                          dataSize, data, FALSE,                                          FALSE, FALSE, NULL); } uint8_t wdata[15] = {"Hello world!\r"}; uint8_t size = sizeof(wdata); SendWriteReq(wdata, size); The data is send with the GattClient_WriteCharacteristicValue() API. This function has various configurable parameters to establish how to send the data. The function's parameters are described with detail on the application developer's guide, but basically, you can determine whether you need or not a response for the server, whether the data is signed or not, etc. Whenever a client makes a read or write request to the server, there is a callback procedure triggered,  to which the program then goes. This callback function has to be registered though. You can register the client callback function using the App_RegisterGattClientProcedureCallback() API: App_RegisterGattClientProcedureCallback(gattClientProcedureCallback); void gattClientProcedureCallback ( deviceId_t deviceId,                                    gattProcedureType_t procedureType,                                    gattProcedureResult_t procedureResult,                                    bleResult_t error ) {   switch (procedureType)   {        /* ... */        case gGattProcWriteCharacteristicValue_c:             if (gGattProcSuccess_c == procedureResult)             {                  /* Continue */             }             else             {                  /* Handle error */             }             break;        /* ... */   } } Reading an attribute is somewhat similar to writing an attribute, you still need the handle for the characteristic, and a buffer in which to store the read value: #define size 17 static void SendReadReq(uint8_t* data, uint8_t dataSize) {     /* Memory has to be allocated for the characteristic because the        GattClient_ReadCharacteristicValue() API runs in a different task, so        it has a different stack. If memory were not allocated, the pointer to        the characteristic would point to junk. */     characteristic = MEM_BufferAlloc(sizeof(gattCharacteristic_t));     data = MEM_BufferAlloc(dataSize);         characteristic->value.handle = charHandle;     characteristic->value.paValue = data;     bleResult_t result = GattClient_ReadCharacteristicValue(mPeerInformation.deviceId, characteristic, dataSize); } uint8_t rdata[size];         SendReadReq(rdata, size); As mentioned before, a callback procedure is triggered whenever there is a write or read request. This is the same client callback procedure used for the write request, but the event generates a different procedure type: void gattClientProcedureCallback ( deviceId_t deviceId,                                    gattProcedureType_t procedureType,                                    gattProcedureResult_t procedureResult,                                    bleResult_t error ) {   switch (procedureType)   {        /* ... */        case gGattProcReadCharacteristicValue_c:             if (gGattProcSuccess_c == procedureResult)             {                  /* Read value length */                  PRINT(characteristic.value.valueLength);                  /* Read data */                  for (uint16_t j = 0; j < characteristic.value.valueLength; j++)                  {                       PRINT(characteristic.value.paValue[j]);                  }             }             else             {               /* Handle error */             }             break;       /* ... */   } } There are some other methods to read an attribute. For further information, refer to the application developer's guide chapter 5, section 5.1.4 Reading and Writing Characteristics. Server Naturally, every time there is a request to either read or write by a client, there must be a response from the server. Similar to the callback procedure from the client, with the server there is also a callback procedure triggered when the client makes a request. This callback function will handle both the write and read requests, but the procedure type changes. This function should also be registered using the  App_RegisterGattServerCallback() API. When there is a read request from a client, the server responds with the read status: App_RegisterGattServerCallback( gattServerProcedureCallback ); void gattServerProcedureCallback ( deviceId_t deviceId,                                    gattServerEvent_t* pServerEvent ) {     switch (pServerEvent->eventType)     {         /* ... */         case gEvtAttributeRead_c:             GattServer_SendAttributeReadStatus(deviceId, value_custom, gAttErrCodeNoError_c);                             break;         /* ... */     } } When there is a write request however, the server should write the received data in the corresponding attribute in the GATT database. To do this, the function GattDb_WriteAttribute() can be used: void gattServerProcedureCallback ( deviceId_t deviceId,                                    gattServerEvent_t* pServerEvent ) {     switch (pServerEvent->eventType)     {         /* ... */         case gEvtAttributeWritten_c:             if (pServerEvent->eventData.attributeWrittenEvent.handle == value_custom)             {                 GattDb_WriteAttribute( pServerEvent->eventData.attributeWrittenEvent.handle,                                        pServerEvent->eventData.attributeWrittenEvent.cValueLength,                                        pServerEvent->eventData.attributeWrittenEvent.aValue );                              GattServer_SendAttributeWrittenStatus(deviceId, value_custom, gAttErrCodeNoError_c);             }             break;         /* ... */     } } If you do not register the server callback function, the attribute can still be written in the GATT database (it is actually done automatically), however, if you want something else to happen when you receive a request (turning on a LED, for example), you will need the server callback procedure.

Bluetooth® Low Energy (or BLE) is a wireless technology that allows the exchange of information between a device that contains data (Server) and a device that requests that data (Client). Servers are usually small battery powered devices connected to sensors or actuators to gather data or perform some actions while clients are usually devices that use that information in a system or for display to a user (most common client devices are the Smartphones). When creating a custom BLE profile, we need to consider that it will need to be implemented on both Server and Client. Server will include the database of all the information that can be accessed or modified while the Client will require drivers to access and handle the data provided by the server. This post explains how to implement a custom profile in the server side using the NXP BLE stack. As example, a custom Potentiometer reporter is implemented on a MKW40Z160. Generic Attribute Profile Before implementing a custom profile, we need to be familiarized with the way BLE exchanges information. The Generic Attribute Profile (GATT) establishes how to exchange all profile and user data over a BLE connection. All standard BLE profiles are based on GATT and must comply with it to operate correctly. GATT defines two communication roles: Server and Client. The GATT Server stores the data to be transported and accepts GATT requests, commands and confirmations from the client. The GATT Client accesses data on the remote GATT server via read, write, notify or indicate operations. Figure 1 GATT Client-Server GATT data is exposed using attributes that are organized to describe the information accessible in a GATT server. These are Profile, Service, Characteristic and Descriptor. Profiles are high level definitions that determine the behavior of the application as a whole (i.e. Heart Rate Monitor, or Temperature Sensor). Profiles are integrated by one or more Services that define individual functionalities (i.e. a Heart Rate Monitor requires a Heart Rate Sensor and a Battery Measurement Unit). Services are integrated by one or more characteristics that hold individual measurements, control points or other data for a service (i.e. Heart Rate Sensor might have a characteristic for Heart Rate and other for Sensor Location). Finally Descriptors define how characteristics must be accessed. Figure 2 GATT database structure Adding a New Service to the GATT Database The GATT database in a server only includes attributes that describe services, characteristics and descriptors. Profiles are implied since they are a set of predefined services. In the NXP Connectivity Software, macros are used to define each of the attributes present in the database in an easier way. Each service and characteristic in a GATT database has a Universally Unique Identifier (UUID). These UUID are assigned by Bluetooth Org on adopted services and characteristics. When working with custom profiles, a proprietary UUID must be assigned. In the NXP connectivity Software, custom UUIDs are defined in the file gatt_uuid128.h. Each new UUID must be defined using the macro UUID128 (name, bytes) where name is an identifier that will help us to reference the UUID later in the code. Byte is a sequence of 16-bytes (128-bits) which are the custom UUID. Following is an example of the definition of the Potentiometer service and the Potentiometer Relative Value characteristic associated to it. /* Potentiometer Service */ UUID128(uuid_service_potentiometer, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x04, 0x56, 0xFF, 0x02) /* Potentiometer Characteristic */ UUID128(uuid_characteristic_potentiometer_relative_value, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x04, 0x57, 0xFF, 0x02) ‍‍‍‍‍‍‍‍‍‍‍ Once proper UUIDs have been stablished, the new service must be added to the GATT database. It is defined in the file gatt_db.h. Simple macros are used to include each of the attributes in the proper order. Following code shows the implementation of the potentiometer service in gatt_db file. PRIMARY_SERVICE_UUID128(service_potentiometer, uuid_service_potentiometer)     CHARACTERISTIC_UUID128(char_potentiometer_relative_value, uuid_characteristic_potentiometer_relative_value, (gGattCharPropRead_c | gGattCharPropNotify_c))         VALUE_UUID128(value_potentiometer_relative_value, uuid_characteristic_potentiometer_relative_value, (gPermissionFlagReadable_c ), 1, 0x00)         CCCD(cccd_potentiometer)         DESCRIPTOR(cpfd_potentiometer, gBleSig_CharPresFormatDescriptor_d, (gPermissionFlagReadable_c), 7, gCpfdUnsigned8BitInteger, 0x00,                    0xAD/*Unit precentage UUID in Little Endian (Lower byte)*/,                    0x27/*Unit precentage UUID in Little Endian (Higher byte)*/,                    0x01, 0x00, 0x00) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ PRIMARY_SERVICE_UUID128 (service_name, service_uuid) defines a new service in the GATT database with a custom 128-bit UUID. It requires two parameters; service_name is the name of this service in the code and it is used later during the program implementation. Service_uuid is the identifier for the service UUID previously defined in gatt_uuid128.h. CHARACTERISTIC_UUID128 (characteristic_name, characteristic_uuid, flags) defines a new characteristic inside the previously defined service with a custom 128-bit UUID. It requires three parameters; characteristic_name is the name of the characteristic in the code, characteristic_uuid is the identifier for the characteristic UUID previously defined in gatt_uuid128.h. Finally, flags is a concatenation of all the characteristic properties (read, write, notify, etc.). VALUE_UUID128 (value_name, characteristic_uuid, permission_flags, number_of_bytes, initial_values…) defines the value in the database of the previously defined characteristic. Value_name is an identifier used later in the code to read or modify the characteristic value. Characteristic_uuid is the same UUID identifier for the previously defined characteristic. Permission_flags determine how the value can be accessed (read, write or both). Number of bytes define the size of the value followed by the initial value of each of those bytes. CCCD (cccd_name) defines a new Client Characteristic Configuration Descriptor for the previously defined characteristic. Cccd_name is the name of the CCCD for use later in the code. This value is optional depending on the characteristic flags. DESCRIPTOR (descriptor_name, descriptor_format, permissions, size, descriptor_bytes…) defines a descriptor for the previously defined characteristic. Descriptor_name defines the name for this descriptor. Descriptor_format determines the type of descriptor. Permissions stablishes how the descriptor is accessed. Finally the size and descriptor bytes are added. All the macros used to fill the GATT database are properly described in the BLEADG (included in the NXP Connectivity Software documentation) under chapter 7 “Creating a GATT Database”. Implementing Drivers for New Service Once the new service has been defined in gatt_db.h, drivers are required to handle the service and properly respond to client requests. To do this, two new files need to be created per every service added to the application; (service name)_service.c and (service name)_interface.h. The service.c file will include all the functions required to handle the service data, and the interface.h file will include all the definitions used by the application to refer to the recently created service. It is recommended to take an existing file for reference. Interface header file shall include the following. Service configuration structure that includes a 16-bit variable for Service Handle and a variable per each characteristic value in the service. /*! Potentiometer Service - Configuration */ typedef struct psConfig_tag {     uint16_t    serviceHandle;                 /*!<Service handle */     uint8_t     potentiometerValue;            /*!<Input report field */ } psConfig_t; ‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Function declarations for the start service and stop service functions. These are required to initialize/deinitialize a service. bleResult_t Ps_Start(psConfig_t *pServiceConfig); bleResult_t Ps_Stop(psConfig_t *pServiceConfig); ‍‍‍‍‍‍ Function declarations for subscribe and unsubscribe functions required to subscribe/unsubscribe a specific client to a service. bleResult_t Ps_Subscribe(deviceId_t clientDeviceId); bleResult_t Ps_Unsubscribe(); ‍‍‍‍‍‍ Depending on your application, functions to read, write, update a specific characteristic or a set of them. bleResult_t Ps_RecordPotentiometerMeasurement (uint16_t serviceHandle, uint8_t newPotentiometerValue);‍‍ Service source file shall include the following. A deviceId_t variable to store the ID for the subscribed client. /*! Potentiometer Service - Subscribed Client*/ static deviceId_t mPs_SubscribedClientId; ‍‍‍‍‍‍ Function definitions for the Start, Stop, Subscribe and Unsubscribe functions. The Start function may include code to set an initial value to the service characteristic values. bleResult_t Ps_Start (psConfig_t *pServiceConfig) {        /* Clear subscibed clien ID (if any) */     mPs_SubscribedClientId = gInvalidDeviceId_c;         /* Set the initial value defined in pServiceConfig to the characteristic values */     return Ps_RecordPotentiometerMeasurement (pServiceConfig->serviceHandle,                                              pServiceConfig->potentiometerValue); } bleResult_t Ps_Stop (psConfig_t *pServiceConfig) {   /* Unsubscribe current client */     return Ps_Unsubscribe(); } bleResult_t Ps_Subscribe(deviceId_t deviceId) {    /* Subscribe a new client to this service */     mPs_SubscribedClientId = deviceId;     return gBleSuccess_c; } bleResult_t Ps_Unsubscribe() {    /* Clear current subscribed client ID */     mPs_SubscribedClientId = gInvalidDeviceId_c;     return gBleSuccess_c; } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Definition of the service specific functions. It is, the functions used to write, read or notify characteristic values. Our example only implements two; a public function to update a characteristic value in the GATT database, and a local function to issue a notification with the recently updated value to the client. bleResult_t Ps_RecordPotentiometerMeasurement (uint16_t serviceHandle, uint8_t newPotentiometerValue) {     uint16_t  handle;     bleResult_t result;     /* Get handle of Potentiometer characteristic */     result = GattDb_FindCharValueHandleInService(serviceHandle,         gBleUuidType128_c, (bleUuid_t*)&potentiometerCharacteristicUuid128, &handle);     if (result != gBleSuccess_c)         return result;     /* Update characteristic value */     result = GattDb_WriteAttribute(handle, sizeof(uint8_t), (uint8_t*)&newPotentiometerValue);     if (result != gBleSuccess_c)         return result;     Ps_SendPotentiometerMeasurementNotification(handle);     return gBleSuccess_c; } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Previous function first obtains the handle value of the characteristic value we want to modify. Handle values are like an index used by the application to access attributes in the database. The UUID for the Potentiometer Relative Value is used to obtain the proper handle by calling GattDb_FindCharValueHandleInService function. Once handle has been obtained, is used in the GattDb_WriteAttribute function to write the new value into the GATT database and it can be accessed by the client. Finally our second function is called to issue a notification. static void Ps_SendPotentiometerMeasurementNotification (   uint16_t handle ) {     uint16_t  hCccd;     bool_t isNotificationActive;     /* Get handle of CCCD */     if (GattDb_FindCccdHandleForCharValueHandle(handle, &hCccd) != gBleSuccess_c)         return;     if (gBleSuccess_c == Gap_CheckNotificationStatus         (mPs_SubscribedClientId, hCccd, &isNotificationActive) &&         TRUE == isNotificationActive)     {         GattServer_SendNotification(mPs_SubscribedClientId, handle);     } } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ SendPotentiometerMeasurementNotification sends a notification to the client. It first obtain the handle value of the CCCD we defined in the GATT database for this characteristic. Then, it checks that the CCCD has been written by the client for notifications. If it has, then it sends the notification so the client can perform a read to the characteristic value. All the functions used to access the GATT database and use the GATT server are better explained in the BLEADG document under chapters 6 and 7. Also instructions on how to create a custom profile are included in chapter 8. BLEADG is part of the NXP Connectivity Software documentation. Integrating a New Service to an Existing BLE Project So far a new service has been created in the database and functions to handle it have been defined. Now this new project must be integrated so it can be managed by the NXP Connectivity Stack. Folder structure of an NXP Connectivity Software project is divided in five different modules. App includes all the application files. Bluetooth contains files related with BLE communications. Framework contains auxiliary software used by the stack for the handling of memory, low power etcetera. KSDK contains the Kinetis SDK drivers for low level modules (ADC, GPIO…) and RTOS include files associated with the operating system. Figure 3 Folder structure Service files must be added to the project under the Bluetooth folder, inside the profiles sub-folder. A new folder must be created for the service.c file and the interface.h file must be added under the interface sub-folder. Figure 4 Service files included Once the files are included in the project, the service must be initialized in the stack. File app.c is the main application file for the NXP BLE stack. It calls all the BLE initializations and application callbacks. The service_interface.h file must be included in this file. Figure 5 Interface header inclusion Then in the local variables definition, a new service configuration variable must be defined for the new service. The type of this variable is the one defined in the service interface file and must be initialized with the service name (defined in gattdb.h) and the initial values for all the characteristic values. Figure 6 Service configuration struct The service now must be initialized. It is performed inside the BleApp_Config function by calling the Start function for the recently added service. static void BleApp_Config() {      /* Read public address from controller */     Gap_ReadPublicDeviceAddress();     /* Register for callbacks*/     App_RegisterGattServerCallback(BleApp_GattServerCallback);       .    .    .    mAdvState.advOn = FALSE;     /* Start services */     Lcs_Start(&lcsServiceConfig);     Dis_Start(&disServiceConfig);     Irs_Start(&irsServiceConfig);     Bcs_Start(&bcsServiceConfig);     Ps_Start(&psServiceConfig); ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Finally, subscribe and unsubscribe functions must be added to the proper host callback. In the BleApp_ConnectionCallback function the subscribe function must be called after the gConnEvtConnected_c (device connected) case, and the unsubscribe function must be called after the gConnEvtDisconnected_c (device disconnected) case. static void BleApp_ConnectionCallback (deviceId_t peerDeviceId, gapConnectionEvent_t* pConnectionEvent) {     switch (pConnectionEvent->eventType)     {         case gConnEvtConnected_c:         {         .         .         .             /* Subscribe client*/             mPeerDeviceId = peerDeviceId;             Lcs_Subscribe(peerDeviceId);             Irs_Subscribe(peerDeviceId);             Bcs_Subscribe(peerDeviceId);             Cts_Subscribe(peerDeviceId);             Ps_Subscribe(peerDeviceId);             Acs_Subscribe(peerDeviceId);             Cps_Subscribe(peerDeviceId);             Rcs_Subscribe(peerDeviceId);         .         .         .         case gConnEvtDisconnected_c:         {         /* UI */           Led1Off();                     /* Unsubscribe client */           mPeerDeviceId = gInvalidDeviceId_c;           Lcs_Unsubscribe();           Irs_Unsubscribe();           Bcs_Unsubscribe();           Cts_Unsubscribe();           Ps_Unsubscribe();           Acs_Unsubscribe();           Cps_Unsubscribe();           Rcs_Unsubscribe(); ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ After this, services can be accessed by a client application. Handling Notifications and Write Requests Once the new service has been initialized, it is possible for the client to access GATT database attributes and issue commands (read, write, notify…). Nevertheless, when an attribute is written or a CCCD is set to start notifications, program must be aware of these requests to handle them if required. Handling Notifications When a characteristic has been configured as notifiable, the client expects to receive messages from it every time in a while depending on the pre-configured parameters. To indicate this, the client writes the specific CCCD for the characteristic indicating that notifications must start/stop being sent. When this occurs, BleApp_GattServerCallback is executed in the main program. All the application CCCDs must be monitored when the gEvtCharacteristicCccdWritten_c event is set. This event indicates that a CCCD has been written. A conditional structure must be programmed to determine which CCCD was modified and act accordingly. static void BleApp_GattServerCallback (deviceId_t deviceId, gattServerEvent_t* pServerEvent) {     switch (pServerEvent->eventType)     {       case gEvtCharacteristicCccdWritten_c:         {             /*             Attribute CCCD write handler: Create a case for your registered attribute and             execute callback action accordingly             */             switch(pServerEvent->eventData.charCccdWrittenEvent.handle)             {             case cccd_input_report:{               //Determine if the timer must be started or stopped               if (pServerEvent->eventData.charCccdWrittenEvent.newCccd){                 // CCCD set, start timer                 TMR_StartTimer(tsiTimerId, gTmrIntervalTimer_c, gTsiUpdateTime_c ,BleApp_TsiSensorTimer, NULL); #if gAllowUartDebug                 Serial_Print(debugUartId, "Input Report notifications enabled \n\r", gNoBlock_d); #endif               }               else{                 // CCCD cleared, stop timer                 TMR_StopTimer(tsiTimerId); #if gAllowUartDebug                 Serial_Print(debugUartId, "Input Report notifications disabled \n\r", gNoBlock_d); #endif               }             }               break;                           case cccd_potentiometer:{               //Determine if the timer must be started or stopped               if (pServerEvent->eventData.charCccdWrittenEvent.newCccd){                 // CCCD set, start timer                 TMR_StartTimer(potTimerId, gTmrIntervalTimer_c, gPotentiometerUpdateTime_c ,BleApp_PotentiometerTimer, NULL); #if gAllowUartDebug                 Serial_Print(debugUartId, "Potentiometer notifications enabled \n\r", gNoBlock_d); #endif               }               else{                 // CCCD cleared, stop timer                 TMR_StopTimer(potTimerId); #if gAllowUartDebug                 Serial_Print(debugUartId, "Potentiometer notifications disabled \n\r", gNoBlock_d); #endif               }             }               break; ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ In this example, when the gEvtCharacteristicCccdWritten_c is set a switch-case selector is executed to determine the written CCCD. This is done by reading the pServerEvent structure in the eventData.charCccdWrittenEvent.handle field. The obtained handle must be compared with the name of the CCCD defined in gatt_db.h for each notifiable characteristic. Figure 7 CCCD name Once the correct CCCD has been detected, the program must determine if it was set or clear. This is done by reading the pServerEvent structure in the eventData.charCccdWrittenEvent.newCccd and executing an action accordingly. In the example code, a timer is started or stopped. Once this timer reaches its modulo value, a new notification is sent using the Ps_RecordPotentiometerMeasurement function previously defined in the service files (see Implementing Drivers for New Service). Handling Write Requests Write request callbacks are not automatically generated like the notification ones. They must be registered during the application initialization. Something to take into account is when this feature is enabled, the written value is not automatically stored in the GATT database. Developers must implement code to do this and perform other application actions if needed.To do this, the GattServer_RegisterHandlesForWriteNotifications function must be called including the handles of all the characteristics that are wanted to generate a callback when written. * Configure writtable attributes that require a callback action */     uint16_t notifiableHandleArray[] = {value_led_control, value_buzzer, value_accelerometer_scale, value_controller_command, value_controller_configuration};     uint8_t notifiableHandleCount = sizeof(notifiableHandleArray)/2;     bleResult_t initializationResult = GattServer_RegisterHandlesForWriteNotifications(notifiableHandleCount, (uint16_t*)&notifiableHandleArray[0]); ‍‍‍‍‍‍‍‍‍ In this example, an array with all the writable characteristics was created. The function that register callbacks requires the quantity of characteristic handles to be registered and the pointer to an array with all the handles. After a client has connected, the gEvtAttributeWritten_c will be executed inside the function BleApp_GattServerCallback every time one of the configured characteristics has been written. Variable pServerEvent->eventData.attributeWrittenEvent.handle must be read to determine the handle of the written characteristic and perform an action accordingly. Depending on the user application, the GATT database must be updated with the new value. To do this, function GattDb_WriteAttribute must be executed. It is recommended to create a function inside the service.c file that updates the attribute in database. case gEvtAttributeWritten_c:         {             /*             Attribute write handler: Create a case for your registered attribute and             execute callback action accordingly             */             switch(pServerEvent->eventData.attributeWrittenEvent.handle){               case value_led_control:{                 bleResult_t result;                                 //Get written value                 uint8_t* pAttWrittenValue = pServerEvent->eventData.attributeWrittenEvent.aValue;                                 //Create a new instance of the LED configurator structure                 lcsConfig_t lcs_LedConfigurator = {                   .serviceHandle = service_led_control,                   .ledControl.ledNumber = (uint8_t)*pAttWrittenValue,                   .ledControl.ledCommand = (uint8_t)*(pAttWrittenValue + sizeof(uint8_t)),                 };                                 //Call LED update function                 result = Lcs_SetNewLedValue(&lcs_LedConfigurator);                                 //Send response to client                 BleApp_SendAttWriteResponse(&deviceId, pServerEvent, &result);                               }               break; ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ After all the required actions have been executed, server must send a response to the client. To do this, function GattServer_SendAttributeWrittenStatus is called including the handle and the error code for the client (OK or any other error status). static void BleApp_SendAttWriteResponse (deviceId_t* pDeviceId, gattServerEvent_t* pGattServerEvent, bleResult_t* pResult){   attErrorCode_t attErrorCode;     // Determine response to send (OK or Error)   if(*pResult == gBleSuccess_c)     attErrorCode = gAttErrCodeNoError_c;   else{     attErrorCode = (attErrorCode_t)(*pResult & 0x00FF);   }   // Send response to client    GattServer_SendAttributeWrittenStatus(*pDeviceId, pGattServerEvent->eventData.attributeWrittenEvent.handle, attErrorCode); } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ More information on how to handle writable characteristics can be found in the BLEADG Chapter 5 (Included in the NXP Connectivity Software documentation). References Bluetooth® Low Energy Application Developer’s Guide (BLEADG)– Included in the NXP Connectivity Software Documentation FRDM-KW40Z Demo Application - Link

Overview Bluetooth Low Energy offers the ability to broadcast data in format of non-connectable advertising packets while not being in a connection. This GAP Advertisement is widely known as a beacon and is used in today’s IoT applications in different forms. This article will present the current beacon format in our demo application from the KW40Z software package and how to create the most popular beacon formats on the market. The advertising packet format and payload are declared in the gAppAdvertisingData structure from app_config.c. This structure points to an array of AD elements, advScanStruct: static const gapAdStructure_t advScanStruct[] = {   {     .length = NumberOfElements(adData0) + 1,     .adType = gAdFlags_c,     .aData = (void *)adData0   },    {     .length = NumberOfElements(adData1) + 1,     .adType = gAdManufacturerSpecificData_c,     .aData = (void *)adData1   } }; Due to the fact that all beacons use the advertising flags structure and that the advertising PDU is 31 bytes in length (Bluetooth Low Energy v4.1), the maximum payload length is 28 bytes, including length and type for the AD elements. The AD Flags element is declared as it follows: static const uint8_t adData0[1] =  { (gapAdTypeFlags_t)(gLeGeneralDiscoverableMode_c | gBrEdrNotSupported_c) }; The demo application uses a hash function to generate a random UUID for the KW40Z default beacon. This is done in BleApp_Init: void BleApp_Init(void) {     sha1Context_t ctx;         /* Initialize sha buffer with values from SIM_UID */     FLib_MemCopy32Unaligned(&ctx.buffer[0], SIM_UIDL);     FLib_MemCopy32Unaligned(&ctx.buffer[4], SIM_UIDML);     FLib_MemCopy32Unaligned(&ctx.buffer[8], SIM_UIDMH);     FLib_MemCopy32Unaligned(&ctx.buffer[12], 0);          SHA1_Hash(&ctx, ctx.buffer, 16);         /* Updated UUID value from advertising data with the hashed value */     FLib_MemCpy(&gAppAdvertisingData.aAdStructures[1].aData[3], ctx.hash, 16); } When implementing a constant beacon payload, please bear in mind to disable this code section. KW40Z Default Beacon The KW40Z software implements a proprietary beacon with the maximum ADV payload and uses the following Manufacturer Specific Advertising Data structure of 26 bytes. This is the default implementation of the beacon demo example from the KW40Z Connectivity Software package. static uint8_t adData1[26] = {     /* Company Identifier*/     0xFF, 0x01     /* Beacon Identifier */     0xBC,     /* UUID */                  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,                                   /* A */                     0x00, 0x00,     /* B */                     0x00, 0x00,     /* C */                     0x00, 0x00,     /* RSSI at 1m */            0x1E}; iBeacon iBeacon is a protocol designed by Apple. It uses a 20 byte payload that consists of the following identifying information [1] : To advertise an iBeacon packet, the user needs to change the second AD element, adData1, like below: static uint8_t adData1[25] = {                                0x4C, 0x00,                                   0x02, 0x15,         /* UUID */             0xD9, 0xB9, 0xEC, 0x1F, 0x39, 0x25, 0x43, 0xD0, 0x80, 0xA9, 0x1E, 0x39, 0xD4, 0xCE, 0xA9, 0x5C,         /* Major Version */    0x00, 0x01         /* Minor Version */    0x00, 0x0A,                                0xC5}; AltBeacon AltBeacon is an open specification designed for proximity beacon advertisements [2]. It also uses a Manufacturer Specific Advertising Data structure: To advertise an AltBeacon packet, the user needs to change the second AD element, like below: static uint8_t adData1[26] = {     /* MFG ID*/         0xFF, 0x01,     /* Beacon Code */   0xBE, 0xAC,     /* Beacon ID */     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04,     /* Ref RSSI*/       0xC5,     /* MFG RSVD*/       0x00}; Eddystone™ Eddystone™ is an open Bluetooth® Smart beacon format from Google [3]. It offers three data type packets: Eddystone™-UID Eddystone™-URL Eddystone™-TLM Eddystone™ uses two advertising structures: Complete List of 16-bit Service UUIDs structure, which contains the Eddystone Service UUID (0xFEAA). Service Data structure, which also contains the Eddystone™ Service UUID (0xFEAA). Thus, advScanStruct will now have 3 elements: static const gapAdStructure_t advScanStruct[] = {   {     .length = NumberOfElements(adData0) + 1,     .adType = gAdFlags_c,     .aData = (void *)adData0   },    {     .length = NumberOfElements(adData1) + 1,     .adType = gAdComplete16bitServiceList_c,     .aData = (void *)adData1   },   {     .length = NumberOfElements(adData2) + 1,     .adType = gAdServiceData16bit_c,     .aData = (void *)adData2   } }; The complete List of 16-bit Service UUIDs element will look like: static const uint8_t adData1[2] =  { 0xAA, 0xFE }; Eddystone™-UID Eddystone™-UID broadcasts a unique 16-bit Beacon ID to identify a particular device in a group. The Service Data block has the following structure: To implement this, the user needs to add a third AD element, as follows: static uint8_t adData2[22] = {     /* ID */ 0xAA, 0xFE,     /* Frame Type */    0x00,     /* Ranging Data */  0xEE,     /* Namespace */     0x8B, 0x0C, 0xA7, 0x50, 0x09, 0x54, 0x77, 0xCB, 0x3E, 0x77,     /* Instance */      0x00, 0x00, 0x00, 0x00, 0x00, 0x01,     /* RFU */           0x00, 0x00}; Eddystone™-URL Eddystone™-URL broadcasts a compressed URL. The Service Data block has the following structure: In this example, we will implement a beacon which will advertise NXP’s webpage, http://www.nxp.com. To implement this, the user needs to add a third AD element, as follows: static const uint8_t adData2[9] = {     /* ID */ 0xAA, 0xFE,     /* Frame Type */    0x10,     /* TX Power */      0xEE,     /* URL scheme */    0x00,     /* Encode URL */    'n', 'x, 'p', 0x07}; Eddystone™-TLM Eddystone™-TLM broadcasts telemetry data about the beacon device operation. The Service Data block has the following structure: To implement this, the user needs to add a third AD element, as follows: static uint8_t adData2[16] = {     /* ID */ 0xAA, 0xFE,     /* Frame Type */    0x20,     /* TLM Version */   0x00,     /* VBATT */        0x00, 0x00,     /* TEMP */         0x00, 0x00,     /* ADV_CNT */      0x00, 0x00, 0x00, 0x00,     /* SEC_CNT */      0x00, 0x00, 0x00, 0x00};

The attached PDF file contains two A3 format "posters". The first one summarize the contents of the SMP Pairing Request and SMP Pairing Response packets (BLE 4.2). It shows how are the sub-fields of these packets set and what do they represent. The second one contains a diagram which summarizes how the pairing method and it's properties are determined during the SMP Pairing procedure for both BLE Legacy Pairing (BLE4.0 and BLE 4.1) and BLE Secure Connections Pairing with ECDH (BLE 4.2). Some of the tables in the diagram are taken from the BLE Specification. If you find any errors or have any suggestions of improvement please leave a comment or send me a message. Preview:

FreeRTOS keeps track of the elapsed time in the system by counting ticks. The tick count increases inside a periodic interrupt routine generated by one of the timers available in the host MCU. When FreeRTOS is running the Idle task hook, the microcontroller can be placed into a low power mode. Depending on the low power mode, one or more peripherals can be disabled in order to save the maximum amount of energy possible. The FreeRTOS tickless idle mode allows stopping the tick interruption during the idle periods. Stopping the tick interrupt allows the microcontroller to remain in a deep power saving state until a wake-up event occurs. The application needs to configure the module (timer, ADC, etc…) that will wake up the microcontroller before the next FreeRTOS task needs to be executed. For this purpose, during the execution of vPortSuppressTicksAndSleep, a function called by FreeRTOS when tickless idle is enabled, the maximum amount of time the MCU can remain asleep is passed as an input parameter in order to properly configure the wake-up module. Once the MCU wakes up and the FreeRTOS tick interrupt is restarted, the number of tick counts lost while the MCU was asleep must be restored. Tickless mode is not enabled by default in the Connectivity Software FreeRTOS demos. In this post, we will show how to enable it. For this example, we will use QN9080x to demonstrate the implementation. lowpower‌ freertos tickless‌ tickless‌ Changes where implemented in the following files: \framework\LowPower\Source\QN908XC\PWR.c \framework\LowPower\Interface\QN908XC\PWR_Interface.h \freertos\fsl_tickless_generic.h \source\common\ApplMain.c The following file was removed from the project fsl_tickless_qn_rtc.c PWR.C and PWR_Interface.h Changes in this files are intended to prepare the QN9080 for waking up using the RTC timer. Other parts, like MKW41Z, might enable other modules for this purpose (like LPTMR) and changes on this files might not be necessary. *** PWR.c *** Add the driver for RTC. This is the timer we will use to wake up the QN908x /*Tickless: Add RTC driver for tickless support */ #include "fsl_rtc.h"‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Add local variables uint64_t mLpmTotalSleepDuration;        //Tickless uint8_t mPWR_DeepSleepTimeUpdated = 0;  //Tickless: Coexistence with TMR manager‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Add private functions uint32_t PWR_RTCGetMsTimeUntilNextTick (void);         //Tickless void PWR_RTCSetWakeupTimeMs (uint32_t wakeupTimeMs);   //Tickless void PWR_RTCWakeupStart (void);                        //Tickless‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Make the following changes in PWR.C. All the required changes are marked as comments with "Start" where the change starts, and with "End where the change ends" #if (cPWR_UsePowerDownMode && (cPWR_EnableDeepSleepMode_1 || cPWR_EnableDeepSleepMode_2 || cPWR_EnableDeepSleepMode_3 || cPWR_EnableDeepSleepMode_4)) static void PWR_HandleDeepSleepMode_1_2_3_4(void) { #if cPWR_BLE_LL_Enable     uint8_t   power_down_mode = 0xff;     bool_t    enterLowPower = TRUE;     __disable_irq(); /****************START***********************************/     /*Tickless: Configure wakeup timer */     if(mPWR_DeepSleepTimeUpdated){       PWR_RTCSetWakeupTimeMs(mPWR_DeepSleepTimeMs);       mPWR_DeepSleepTimeUpdated = FALSE;        // Coexistence with TMR Manager     }         PWR_RTCWakeupStart(); /*****************END**************************************/     PWRLib_ClearWakeupReason();     //Try to put BLE in deep sleep mode     power_down_mode = BLE_sleep();     if (power_down_mode < kPmPowerDown0)     {         enterLowPower = false; // BLE doesn't allow deep sleep     }     //no else - enterLowPower is already true     if(enterLowPower)     { /****************START**************************/         uint32_t freeRunningRtcPriority; /****************END****************************/         NVIC_ClearPendingIRQ(OSC_INT_LOW_IRQn);         NVIC_EnableIRQ(OSC_INT_LOW_IRQn);         while (SYSCON_SYS_STAT_OSC_EN_MASK & SYSCON->SYS_STAT) //wait for BLE to enter sleep         {             POWER_EnterSleep();         }         NVIC_DisableIRQ(OSC_INT_LOW_IRQn);         if(gpfPWR_LowPowerEnterCb != NULL)         {             gpfPWR_LowPowerEnterCb();         } /* Disable SysTick counter and interrupt */         sysTickCtrl = SysTick->CTRL & (SysTick_CTRL_ENABLE_Msk | SysTick_CTRL_TICKINT_Msk);         SysTick->CTRL &= ~(SysTick_CTRL_ENABLE_Msk | SysTick_CTRL_TICKINT_Msk);         ICSR |= (1 << 25); // clear PendSysTick bit in ICSR, if set /************************START***********************************/         NVIC_ClearPendingIRQ(RTC_FR_IRQn);         freeRunningRtcPriority = NVIC_GetPriority(RTC_FR_IRQn);         NVIC_SetPriority(RTC_FR_IRQn,0); /***********************END***************************************/         POWER_EnterPowerDown(0); //Nighty night! /************************START**********************************/         NVIC_SetPriority(RTC_FR_IRQn,freeRunningRtcPriority); /************************END************************************/         if(gpfPWR_LowPowerExitCb != NULL)         {             gpfPWR_LowPowerExitCb();         }         /* Restore the state of SysTick */         SysTick->CTRL |= sysTickCtrl;         PWRLib_UpdateWakeupReason();     }     __enable_irq(); #else     PWRLib_ClearWakeupReason(); #endif /* cPWR_BLE_LL_Enable */ } #endif /* (cPWR_UsePowerDownMode && cPWR_EnableDeepSleepMode_1) */ ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ void PWR_SetDeepSleepTimeInMs(uint32_t deepSleepTimeMs) { #if (cPWR_UsePowerDownMode)     if(deepSleepTimeMs == 0)     {         return;     }     mPWR_DeepSleepTimeMs = deepSleepTimeMs; /****************START******************/     mPWR_DeepSleepTimeUpdated = TRUE; /****************END*********************/ #else     (void) deepSleepTimeMs; #endif /* (cPWR_UsePowerDownMode) */ }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Add/replace the following function definitions at the end of the file /*--------------------------------------------------------------------------- * Name: PWR_GetTotalSleepDurationMS * Description: - * Parameters: - * Return: - *---------------------------------------------------------------------------*/ uint32_t PWR_GetTotalSleepDurationMS(void) {     uint32_t time;     uint32_t currentSleepTime;     OSA_InterruptDisable();     currentSleepTime = RTC_GetFreeRunningInterruptThreshold(RTC);     if(currentSleepTime >= mLpmTotalSleepDuration){     time = (currentSleepTime-mLpmTotalSleepDuration)*1000/CLOCK_GetFreq(kCLOCK_32KClk);     }     else{     time = ((0x100000000-mLpmTotalSleepDuration)+currentSleepTime)*1000/CLOCK_GetFreq(kCLOCK_32KClk);     }     OSA_InterruptEnable();     return time; } /*--------------------------------------------------------------------------- * Name: PWR_ResetTotalSleepDuration * Description: - * Parameters: - * Return: - *---------------------------------------------------------------------------*/ void PWR_ResetTotalSleepDuration(void) {     OSA_InterruptDisable();     mLpmTotalSleepDuration = RTC_GetFreeRunningCount(RTC);     OSA_InterruptEnable(); } /*--------------------------------------------------------------------------- * Name: PWR_RTCGetMsTimeUntilNextTick * Description: - * Parameters: - * Return: Time until next tick in mS *---------------------------------------------------------------------------*/ uint32_t PWR_RTCGetMsTimeUntilNextTick (void) {     uint32_t time;     uint32_t currentRtcCounts, thresholdRtcCounts;     OSA_InterruptDisable();     currentRtcCounts = RTC_GetFreeRunningCount(RTC);     thresholdRtcCounts = RTC_GetFreeRunningResetThreshold(RTC);     if(thresholdRtcCounts > currentRtcCounts){     time = (thresholdRtcCounts-currentRtcCounts)*1000/CLOCK_GetFreq(kCLOCK_32KClk);     }     else{     time = ((0x100000000-currentRtcCounts)+thresholdRtcCounts)*1000/CLOCK_GetFreq(kCLOCK_32KClk);     }     OSA_InterruptEnable();     return time; } /*--------------------------------------------------------------------------- * Name: PWR_RTCSetWakeupTimeMs * Description: - * Parameters: wakeupTimeMs: New wakeup time in milliseconds * Return: - *---------------------------------------------------------------------------*/ void PWR_RTCSetWakeupTimeMs (uint32_t wakeupTimeMs){     uint32_t wakeupTimeTicks;     uint32_t thresholdValue;     wakeupTimeTicks = (wakeupTimeMs*CLOCK_GetFreq(kCLOCK_32KClk))/1000;     thresholdValue = RTC_GetFreeRunningCount(RTC);     thresholdValue += wakeupTimeTicks;     RTC_SetFreeRunningInterruptThreshold(RTC, thresholdValue); } /*--------------------------------------------------------------------------- * Name: PWR_RTCWakeupStart * Description: - * Parameters: - * Return: - *---------------------------------------------------------------------------*/ void PWR_RTCWakeupStart (void){   if(!(RTC->CNT2_CTRL & RTC_CNT2_CTRL_CNT2_EN_MASK)){     RTC->CNT2_CTRL |= 0x52850000 | RTC_CNT2_CTRL_CNT2_EN_MASK | RTC_CNT2_CTRL_CNT2_WAKEUP_MASK | RTC_CNT2_CTRL_CNT2_INT_EN_MASK;   }   else{     RTC->CNT2_CTRL |= 0x52850000 | RTC_CNT2_CTRL_CNT2_WAKEUP_MASK | RTC_CNT2_CTRL_CNT2_INT_EN_MASK;   } } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍  *** PWR_Interface.h *** Add the following function declarations at the end of the file /*--------------------------------------------------------------------------- * Name: PWR_GetTotalSleepDurationMS * Description: - * Parameters: - * Return: - *---------------------------------------------------------------------------*/ uint32_t PWR_GetTotalSleepDurationMS(void); /*--------------------------------------------------------------------------- * Name: PWR_ResetTotalSleepDuration * Description: - * Parameters: - * Return: - *---------------------------------------------------------------------------*/ void PWR_ResetTotalSleepDuration(void); #ifdef __cplusplus } #endif #endif /* _PWR_INTERFACE_H_ */ ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ FSL_TICKLESS_GENERIC The following changes have the purpose of preparing the system for recovering the missed ticks during the low power period. Make the following changes in fsl_tickless_generic.h. All the required changes are marked as comments with "Start" where the change starts, and with "End where the change ends" /* QN_RTC: The RTC free running is a 32-bit counter. */ #define portMAX_32_BIT_NUMBER (0xffffffffUL) #define portRTC_CLK_HZ (0x8000UL) /* A fiddle factor to estimate the number of SysTick counts that would have occurred while the SysTick counter is stopped during tickless idle calculations. */ #define portMISSED_COUNTS_FACTOR (45UL) /* * The number of SysTick increments that make up one tick period. */ /****************************START**************************/ #if configUSE_TICKLESS_IDLE == 1     static uint32_t ulTimerCountsForOneTick; #endif /* configUSE_TICKLESS_IDLE */ /************************END*********************************/ /* * Setup the timer to generate the tick interrupts. */ void vPortSetupTimerInterrupt(void); #ifdef __cplusplus } #endif #endif /* FSL_TICKLESS_GENERIC_H */ ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ ApplMain.c This is the main application file. Here is where we will call the proper APIs to enter the MCU in low power mode and perform the tick recovery sequence. Include RTC and FreeRTOS header files needed /*Tickless: Include RTC and FreeRTOS header files */ #include "fsl_rtc.h" #include "fsl_tickless_generic.h" #include "FreeRTOS.h" #include "task.h"‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ QN9080 includes several low power modes. Sleep mode maintains most of the modules active. Power Down modes turn off most of the modules but allow the user to configure some modules to remain active to wake the MCU up when necessary. Using tickless FreeRTOS involves having to wake-up by some timer before the next ready task has to execute. For QN908x this timer will be the RTC which requires the 32.768kHz oscillator to remain active. We will change the Connectivity Software Power Lib to use Deep Sleep mode 3 (Power Down mode 0 for QN908x) which maintains the 32.768kHz oscillator on. This change is implemented in the main_task function. #if !defined(MULTICORE_BLACKBOX)         /* BLE Host Stack Init */         if (Ble_Initialize(App_GenericCallback) != gBleSuccess_c)         {             panic(0,0,0,0);             return;         } #endif /* MULTICORE_BLACKBOX */ /*************** Start ****************/ #if (cPWR_UsePowerDownMode)     PWR_ChangeDeepSleepMode(3); #endif /*************** End ****************/     }         /* Call application task */     App_Thread( param ); }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Also, tickless FreeRTOS requires a special Idle function which takes as an input parameter the amount of RTOS ticks the MCU can remain asleep before the next task needs to be executed. The following changes disable the default Idle function provided in the Connectivity Software demos when the tickless mode is enabled. /************************************************************************************ ************************************************************************************* * Private prototypes ************************************************************************************* ************************************************************************************/ #if (cPWR_UsePowerDownMode || gAppUseNvm_d) #if (mAppIdleHook_c)     #define AppIdle_TaskInit()     #define App_Idle_Task() #else #if (!configUSE_TICKLESS_IDLE)     static osaStatus_t AppIdle_TaskInit(void);     static void App_Idle_Task(osaTaskParam_t argument); #endif // configUSE_TICKLESS_IDLE #endif #endif‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ /************************************************************************************ ************************************************************************************* * Private memory declarations ************************************************************************************* ************************************************************************************/ /******************************** Start ******************************/ #if ((cPWR_UsePowerDownMode || gAppUseNvm_d) && !configUSE_TICKLESS_IDLE) /******************************** End ******************************/ #if (!mAppIdleHook_c) OSA_TASK_DEFINE( App_Idle_Task, gAppIdleTaskPriority_c, 1, gAppIdleTaskStackSize_c, FALSE ); osaTaskId_t gAppIdleTaskId = 0; #endif #endif  /* cPWR_UsePowerDownMode */‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ #if !gUseHciTransportDownward_d         pfBLE_SignalFromISR = BLE_SignalFromISRCallback; #endif /* !gUseHciTransportDownward_d */ /**************************** Start ************************/ #if ((cPWR_UsePowerDownMode || gAppUseNvm_d) && !configUSE_TICKLESS_IDLE) /**************************** End ************************/ #if (!mAppIdleHook_c)         AppIdle_TaskInit(); #endif #endif‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ /***************************START**************************/ #if (cPWR_UsePowerDownMode && !configUSE_TICKLESS_IDLE) /******************************END***************************/ static void App_Idle(void) {     PWRLib_WakeupReason_t wakeupReason;     if( PWR_CheckIfDeviceCanGoToSleep() )     {         /* Enter Low Power */         wakeupReason = PWR_EnterLowPower(); #if gFSCI_IncludeLpmCommands_c         /* Send Wake Up indication to FSCI */         FSCI_SendWakeUpIndication(); #endif #if gKBD_KeysCount_c > 0         /* Woke up on Keyboard Press */         if(wakeupReason.Bits.FromKeyBoard)         {             KBD_SwitchPressedOnWakeUp();             PWR_DisallowDeviceToSleep();         } #endif     }     else     {         /* Enter MCU Sleep */         PWR_EnterSleep();     } } #endif /* cPWR_UsePowerDownMode */ #if (mAppIdleHook_c) void vApplicationIdleHook(void) { #if (gAppUseNvm_d)     NvIdle(); #endif /*******************************START****************************/ #if (cPWR_UsePowerDownMode && !configUSE_TICKLESS_IDLE) /*********************************END*******************************/     App_Idle(); #endif } #else /* mAppIdleHook_c */ /******************************* START ****************************/ #if ((cPWR_UsePowerDownMode || gAppUseNvm_d) && !configUSE_TICKLESS_IDLE) /******************************* END ****************************/ static void App_Idle_Task(osaTaskParam_t argument) {     while(1)     {   #if gAppUseNvm_d         NvIdle(); #endif         #if (cPWR_UsePowerDownMode)         App_Idle(); #endif         /* For BareMetal break the while(1) after 1 run */         if (gUseRtos_c == 0)         {             break;         }     } } ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Once the default Idle function has been disabled, the special Idle function must be implemented. Add the following code at the end of the ApplMain.c file. /*Tickless: Implement Tickless Idle */ #if (cPWR_UsePowerDownMode && configUSE_TICKLESS_IDLE) extern void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime ) {     uint32_t time_ms = xExpectedIdleTime * portTICK_PERIOD_MS;     uint32_t tmrMgrExpiryTimeMs;     ulTimerCountsForOneTick = 160000;//VALUE OF THE SYSTICK 10 ms #if (cPWR_UsePowerDownMode)     PWRLib_WakeupReason_t wakeupReason;         //TMR_MGR: Get next timer manager expiry time     tmrMgrExpiryTimeMs = TMR_GetFirstExpireTime(gTmrAllTypes_c);     // TMR_MGR: Update RTC Threshold only if RTOS needs to wakeup earlier     if(time_ms<tmrMgrExpiryTimeMs){       PWR_SetDeepSleepTimeInMs(time_ms);     }         PWR_ResetTotalSleepDuration();     if( PWR_CheckIfDeviceCanGoToSleep() )     {         wakeupReason = PWR_EnterLowPower();                 //Fix: All the tick recovery stuff should only happen if device entered in DSM         xExpectedIdleTime = PWR_GetTotalSleepDurationMS() / portTICK_PERIOD_MS;     // Fix: ticks = time in mS asleep / mS per each tick (portTICK_PERIOD_MS)         /* Restart SysTick so it runs from portNVIC_SYSTICK_LOAD_REG         again, then set portNVIC_SYSTICK_LOAD_REG back to its standard         value. The critical section is used to ensure the tick interrupt         can only execute once in the case that the reload register is near         zero. */         portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL;         portENTER_CRITICAL();         portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT;         vTaskStepTick( xExpectedIdleTime );         portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL;         portEXIT_CRITICAL(); #if gKBD_KeysCount_c > 0         /* Woke up on Keyboard Press */         if(wakeupReason.Bits.FromKeyBoard)         {           KBD_SwitchPressedOnWakeUp();           PWR_DisallowDeviceToSleep();         } #endif     }     else     {       /* Enter MCU Sleep */       PWR_EnterSleep();     } #endif /* cPWR_UsePowerDownMode */ } #endif  //cPWR_UsePowerDownMode && configUSE_TICKLESS_IDLE ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ From the previous function, the value of ulTimerCountsForOneTick is used to restore the count of the RTOS tick timer after waking up. This value depends on the RTOS Tick interval defined in FreeRTOSConfig.h and is calculated using the following formula: SYST_RNR  =  F_Systick_CLK(Hz) * T_FreeRTOS_Ticks(ms) Where:       F_Systick_CLK(Hz) = AHB or 32KHz of the SYST_CSR selection       T_FreeRTOS_Ticks(ms) = tick count value. FreeRTOSConfig.h Finally, on the FreeRTOSConfig.h file, make sure that configUSE_TICKLESS_IDLE is set to 1 * See http://www.freertos.org/a00110.html. *----------------------------------------------------------*/ #define configUSE_PREEMPTION                    1 #define configUSE_TICKLESS_IDLE                 1 //<--- /***** Start *****/ #define configCPU_CLOCK_HZ                      (SystemCoreClock) #define configTICK_RATE_HZ                      ((TickType_t)100) #define configMAX_PRIORITIES                    (18) #define configMINIMAL_STACK_SIZE                ((unsigned short)90)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Testing Tickless RTOS In order to test if tickless support was successfully added, an example application that toggles an LED is implemented. This application configures an RTOS timer to toggle the LED once every 500mS and enter the MCU in DSM3 during the idle time. The Power Profiling demo was used for this purpose. power_profiling.c Make sure you have included the following header files #include "FreeRTOS.h" #include "task.h"‍‍‍‍ Create an RTOS task for blinking the LED every 500mS. First, declare the task function, task ID and the task itself. void vfnTaskLedBlinkTest(void* param); //New Task Definition OSA_TASK_DEFINE(vfnTaskLedBlinkTest, 1, 1, 500, FALSE ); osaTaskId_t gAppTestTask1Id = 0; // TestTask1 Id‍‍‍‍‍‍ Create the new task inside the BleApp_Init function void BleApp_Init(void) {     PWR_AllowDeviceToSleep();     mPowerState = 0;   // Board starts with PD1 enabled     /******************* Start *****************/     gAppTestTask1Id = OSA_TaskCreate(OSA_TASK(vfnTaskLedBlinkTest), NULL); //Task Creation     /*******************  End  *****************/ }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Finally, add the task function definition at the end of the file. void vfnTaskLedBlinkTest(void* param) {     uint16_t wTimeValue = 500; //500ms     while(1)     {         LED_BLUE_TOGGLE();         vTaskDelay(pdMS_TO_TICKS(wTimeValue));     } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ We can monitor the power consumption in MCUXpresso IDE, with the Power Measurement Tool. With it, we can see the current that is been consumed and prove that the implementation is working as the expected. Configure the Power Measurement Tool Consumed current

This document describes how to sniff ZigBee packets to identify messages and layers from the ZigBee stack using the MC1322x USB dongle and Wireshark protocol analyzer. --------------------------------------------------------------------------------------------------------- Pre-Requisites If not done yet, download & Install Wireshark protocol analyzer http://www.wireshark.org/download.html Download the Wireshark ZigBee Utility Zip file from Sourceforge http://sourceforge.net/projects/wiresharkzigbee/ Unzip the file in a known location -------------------------------------------------------------------------------------------------------- 1. Install MC1322x dongle Plug-in MC1322xUSB dongle and wait for Windows to install the driver. If the driver was not found, steer Windows manually to the directory         C:\Program Files\Freescale\Drivers If BeeKit is not installed, be aware of the following: The 1322x USB Dongle uses the FTDI serial to USB converter, Virtual COM Port (VCP) driver for Windows, available at www.ftdichip.com/ftdrivers.htm. The FTDI web site offers drivers for other platforms including Windows® (98 through Vista x64 and CE), MAC OS (8 through X) and Linux. Download the appropriate driver and follow the instructions to complete driver installation. 2. Check COM port Once installed, the MC1322xUSB dongle should be listed in the available COM ports in Widows device manager. Verify the board’s drivers were successfully installed and take note of the COM port assigned      3. Run the ZigBee Utility Open a command console and navigate to the directory where Wireshark Zigbee utility files were unzipped. c:\<path> Then start the .exe utility and set the serial port and ZigBee channel to monitor, for instance:     4. Setting Wireshark Start Wireshark and open Capture>Options Dialog Click on “Manage Interfaces” and add a new pipe with ‘\\.\pipe\wireshark’. Save it and start capture. 5. Start sniffing

This document describes a simple process for enabling the user controls the radio through serial commands. Hardware requirements: • FRDM-KW41Z/QN902x board or a board programmed with HCI black box application. Software requirements: • Test Tool 12 application. It can be downloaded from the NXP web page. • HCI Black Box binary.   Running Demo 1. Load the board with hci_black_box example. 2. Open the Test Tool 12 software 3. Set up the correct Serial Configuration. If there were no changes in the application the default configuration will correspond to the one showed in the following figure. 4. Double click on the active device that you want to test, this will open the COM port in the command console. 5. Set the command set to the BLE_HCI.xml. This file has a list of the HCI commands that the user can send to the device, some of the commands have some options to be configured if necessary or some data to be filled. 6. To make easier the use of frequent commands, there is the option to add a shortcut to the command and the chosen behavior will be added to the panel. 7. Once you add the shortcut or choose the command or your preference, just double click over it and the tool will send the command to the device. In this case, we will send a reset on the board, this command does not receive any extra parameters, data or need any extra configuration.   8. If successful there will be a response or acknowledge of the behavior that will be shown in the right panel. Hope it helps. Regards, Mario

This document and the attached files are maintained up to date in collaboration with Dragos Musoiu. This document is a supplement for USB MSC device bootloader revision for FRDM-KL25Z (IAR) written by Kai Liu and describes the bootloader support for USB-KW24D512. How to use 1) Connect the USB-KW24D512 to the PC USB port; 2) Download the attached file ‘USB_KW24D512_MSD_Bootloader.bin’ to the flash memory of the MKW24D512 SiP following the next steps: Connect a J-Link programmer to the PC USB port (other than the one used for the USB-KW24D512 dongle); Navigate to your J-Link driver folder using a command console and type ‘jlink.exe’ followed by enter; After the apparition of the J-Link prompter, type ‘unlock kinetis’ followed by enter; Wait for the unlock command confirmation and after, type ‘device mkw24d512xxx5’ followed by enter; After the J-Link prompter appears type ‘loadbin USB_KW24D512_MSD_Bootloader.bin 0’ followed by enter; (Be sure you copied the ‘USB_KW24D512_MSD_Bootloader.bin’ file in the same directory with jlink.exe otherwise, type the command specifying the full path of the binary file); After the flashing process successfully finished type ‘exit’ followed by enter. 3) Reset or reconnect the USB-KW24D512; 4) The OS will prompt MSD device connecting and then BOOTLOADER drive will appear. The bootloader software was tested on Microsoft Windows 10, Microsoft Windows 8.1, Microsoft Windows 7, Ubuntu 14.04 and MAC operating systems. 5) Copy and paste any user application .SREC or .bin file into BOOTLOADER drive; 6) If a valid .SREC or .bin file was given, the board restarts and starts to run the user application. Please refer to the Notes section in order to create valid .SREC or .bin files. Note:            The bootloader has conditional jump to user application. The condition is the state of the SW1 button (PTC4). If the button is pressed (PTC4 grounded) during reset, the bootloader sequence will start, installing BOOTLOADER drive, as described before. Else if the button is released during reset, the SP and PC will be updated from address 0xC000. This means, the user application has to use a linker file which forces the application start address to 0xC000. If a valid SP and PC value is found at address 0xC000, the user application is launched. The bootloader application is located in the flash memory of the MKW24D512 SiP, from address 0x0000 to 0xBFFF, so the user application should not put any code in this memory region. Avoid using .SREC or .bin files having program bytes or fill patterns in the bootloader section. Attached files: USB_KW24D512_MSD_Bootloader.bin – bootloader binary file for USB-KW24D512; Pflash_512KB_0xC000.icf – IAR linker file for user application development; 802.15.4SnifferOnUSB.bin – user application demo binary file for KW24D512-USB. Be aware that the file ‘802.15.4SnifferOnUSB.srec’ is linked according to the above memory restrictions and is working only with the bootloader presented in this document.

Introduction Over The Air Programming (OTAP) is a Bluetooth LE custom NXP's service that provides a solution to upgrade the software running in the microcontroller. This document guides to load a new software image in a KW38 device through (Over The Air Programming) OTAP Bluetooth LE service. Software Requirements MCUXpresso IDE or IAR Embedded Workbench IDE. FRDM-KW38 SDK. IoT Toolbox App, available for Android and iOS. You can also download the APK of the IoT Toolbox App from this post: IoT Toolbox for Android  Hardware Requirements FRDM-KW38 board. A smartphone with IoT Toolbox App. KW38 Flash Memory Used by the OTAP Client Software During the Update Process By default, the 512KB KW38 flash memory is partitioned into: One 256KB Program Flash array (P-Flash) divided into 2KB sectors with a flash address range from 0x0000_0000 to 0x0003_FFFF. One 256KB FlexNVM array divided into 2KB sectors with address range from 0x1000_0000 to 0x1003_FFFF. Alias memory with address range from 0x0004_0000 to 0x0007_FFFF. Writes or reads at the Alias memory modifies or returns the FlexNVM content, respectively. In other words, Alias memory is another way to refer to FlexNVM memory using different addresses. The following statements simplify how does the OTAP service work:   The OTAP application consists of two independent parts, OTAP bootloader, and OTAP client. The OTAP bootloader verifies if there is a new image available in the OTAP client to reprogram the device. The OTAP client software, on the other hand, provides the Bluetooth LE custom service needed to communicate the OTAP client device (device to be reprogrammed) with the OTAP server device (device that contains the image to reprogram the OTAP client device). Therefore, to prepare the software for the first time, the OTAP client device needs to be programmed twice, first with the OTAP bootloader, and then with the OTAP client software. The mechanism created to have two different software coexisting in the same device is storing each one in different memory regions. This is achieved by indicating to the linker file different memory regions on each individual software. For the KW38 device, the OTAP bootloader has reserved an 8KB slot from 0x0000_0000 to 0x0000_1FFF, thus the rest of the memory is reserved, among other things, by the OTAP client software.     When generating the new image file for the OTAP client device, we need to specify to the linker file that the code will be placed with an offset of 8KB (as the OTAP client software does), since these address range must be preserved to do not overwrite the OTAP bootloader. The new application should also contain the bootloader flags at the corresponding address to work properly (later we will return to this point).     While OTAP client and OTAP server devices are connected, and the download is in progress, the OTAP server device sends the image packets (known as chunks) to the OTAP client device via Bluetooth LE. The OTAP client device can store these chunks, in the external SPI flash (which is already populated on the FRDM-KW38) or in the on-chip FlexNVM region. The destination for these chunks is selectable in the OTAP client software (This post will give the instructions to modify the destination).     When the transfer of the image has finished, and all chunks were sent from the OTAP server device to the OTAP client device, the OTAP client software writes information such as the source of the software update (either external flash or FlexNVM) in a portion of memory known as bootloader flags. Then the OTAP client performs a software reset on the MCU to execute the OTAP bootloader code. Then, the OTAP bootloader code reads the bootloader flags to get the information needed to reprogram the device with the new application. See the following flow diagram which explains the flow of both applications.   Because the new application was built with an offset of 8KB, the OTAP bootloader programs the device starting from the 0x0000_2000 address, so, in consequence, the OTAP client application is overwritten by the new image. Then, the OTAP bootloader moves the flow of the application to start the execution of the new code.     In practice, the boundary between the OTAP client software and the software update when FlexNVM storage is enabled described in statement 3 is not placed exactly in the boundary of the P-Flash and FlexNVM memory regions, moreover, these values might change depending on your linker settings. To know where is located the boundary, you should inspect the effective memory addressing in your project.        Configuring and Programming OTAP Client Software in IAR Embedded Workbench IDE As mentioned in the last section, to complete the software for OTAP implementation, there are required two software programmed in your FRDM-KW38, OTAP bootloader and OTAP client. This section guides you to program and configure the settings to choose between external or internal storage using the IAR Embedded Workbench IDE. 1- The first step is to program the OTAP bootloader in your KW38. Unzip your SDK and then locate the OTAP bootloader software in the following path: <KW38_SDK>\boards\frdmkw38\wireless_examples\framework\bootloader_otap\bm\iar\bootloader_otap.eww 2- Program the OTAP bootloader project on your board by clicking on the "Download and Debug" icon (Ctrl + D) . Once the KW38 was programmed and the debug session begun, abort the session (Ctrl + Caps Lock + D)  to stop the MCU safely. 3- At this point, you have programmed the OTAP bootloader in your KW38. The next is to program and configure the OTAP client software. Locate the OTAP client software at the following path: Freertos project version: <KW38_SDK>\boards\frdmkw38\wireless_examples\bluetooth\otac_att\freertos\iar\otap_client_att_freertos.eww Baremetal project version: <KW38_SDK>\boards\frdmkw38\wireless_examples\bluetooth\otac_att\bm\iar\otap_client_att_bm.eww 4- Then, configure the OTAP client to select external or internal storage. To select the external storage, follow the next steps (this is the default configuration in the SDK project): 4.1- Locate the "app_preinclude.h" header file in the source folder of your workspace. Search the "gEepromType_d" define and set its value to "gEepromDevice_AT45DB041E_c". /* Specifies the type of EEPROM available on the target board */ #define gEepromType_d gEepromDevice_AT45DB041E_c 4.2- Open the project options window (Alt + F7). Go to Linker->Config window and set "gUseInternalStorageLink_d=0".   To select the internal storage, follow the next steps: 4.1- Locate the "app_preinclude.h" header file in the source folder of your workspace. Search the "gEepromType_d" define and set its value to "gEepromDevice_InternalFlash_c". /* Specifies the type of EEPROM available on the target board */ #define gEepromType_d gEepromDevice_InternalFlash_c 4.2- Open the project options window (Alt + F7). Go to Linker->Config window and set "gUseInternalStorageLink_d=1".   5- Once you have configured the storage settings, save the changes in the project. Then program the software on your board by clicking on the "Download and Debug" icon (Ctrl + D)  . Once the KW38 was programmed and the debug session began, abort the session (Ctrl + Caps Lock + D)  to stop the MCU safely. Creating an SREC Image to Update the Software in OTAP Client in IAR Embedded Workbench IDE This section shows how to create an image compatible with OTAP to reprogram the KW38 OTAP Client using as a starting point, our wireless examples with IAR Embedded Workbench IDE. 1- Select any example from your SDK package in the Bluetooth folder and open it using the IAR IDE. Bluetooth examples are located in the following path: <KW38_SDK>\boards\frdmkw38\wireless_examples\bluetooth  In this example, we will use the glucose sensor project: <KW38_SDK>\boards\frdmkw38\wireless_examples\bluetooth\glucose_s\freertos\iar\glucose_sensor_freertos.eww 2- Open the project options window in IAR (Alt + F7). In Linker->Config window, edit the options to include the "gUseBootloaderLink_d=1" flag and update the "gEraseNVMLink_d=0" flag. When the gUseBootlaoderLink_d flag is true, it indicates to the linker file that the image must be addressed after the first flash sector, to do not overwrite the OTAP Bootloader software (as we stated previously). On the other hand, the gEraseNVMLink_d symbol is used to fill with a 0xFF pattern the unused NVM flash memory region. Disabling this flag, our software image will not contain this pattern, in consequence, the image reduces its total size and it improves the speed of the OTAP download and memory usage. 3- Go to "Output Converter" window. Deselect the "Override default" checkbox, then expand the "Output format" combo box and select "Motorola S-records" format. Click the "OK" button to finish. 4- Build the project. 5- Locate the S-Record file (.srec) in the following path, and save it to a known location on your smartphone. <KW38_SDK>\boards\frdmkw38\wireless_examples\bluetooth\glucose_s\freertos\iar\debug\glucose_sensor_freertos.srec Configuring and Programming OTAP Client Software in MCUXpresso IDE As mentioned in a previous section, to complete the software for OTAP implementation, there are required two software programmed in your FRDM-KW38, OTAP bootloader and OTAP client. This section guides you to program and configure the settings to choose between external or internal storage using the MCUXpresso IDE. 1- Open MCUXpresso IDE. Click on "Import SDK example(s)" in the "Quickstart Panel". 2- Select the FRDM-KW38 icon and click "Next >". 3- Import the OTAP bootloader project. It is located in "wireless_examples -> framework -> bootloader_otap -> bm -> bootloader_otap". Click on the "Finish" button. 4- Program the OTAP bootloader project on your board by clicking on the "Debug" icon  . Once the KW38 was programmed and the debug session begun, abort the session  (Ctrl + F2) to stop the MCU safely. 5- Repeat steps 1 to 3 to import the OTAP client software on MCUXpresso IDE. It is located at "wireless_examples -> bluetooth -> otac_att -> freertos -> otap_client_att_freertos" for freertos version, or "wireless_examples -> bluetooth -> otac_att -> bm -> otap_client_bm_freertos" if you prefer baremetal instead. 6- Then, configure the OTAP client to select external or internal storage. To select the external storage, follow the next steps (this is the default configuration in the SDK project): 6.1- Locate the "app_preinclude.h" file under the source folder in your workspace. Search the "gEepromType_d" define and set its value to "gEepromDevice_AT45DB041E_c". /* Specifies the type of EEPROM available on the target board */ #define gEepromType_d gEepromDevice_AT45DB041E_c 6.2- Navigate to "Project -> Properties -> C/C++ Build -> MCU settings -> Memory details". Edit the Flash fields as shown in the figure below, and leave intact the RAM. To select the internal storage, follow the next steps: 6.1- Locate the "app_preinclude.h" file under the source folder in your workspace. Search the "gEepromType_d" define and set its value to "gEepromDevice_InternalFlash_c". /* Specifies the type of EEPROM available on the target board */ #define gEepromType_d gEepromDevice_InternalFlash_c 6.2- Navigate to "Project -> Properties -> C/C++ Build -> MCU settings -> Memory details". Edit the Flash fields as shown in the figure below, and leave intact the RAM. 7- Once you have configured the storage settings, save the changes in the project. Then program the software on your board by clicking on the "Debug" icon  . Once the KW38 was programmed and the debug session begun, abort the session  (Ctrl + F2) to stop the MCU safely. Creating an SREC Image to Update the Software in OTAP Client in MCUXpresso IDE This section shows how to create an image compatible with OTAP to reprogram the KW38 OTAP Client using as a starting point, our wireless examples with MCUXpresso IDE. 1- Import any example from your SDK package in the Bluetooth folder as explained previously. Bluetooth examples are located in "wireless_examples -> bluetooth" folder in the SDK Import Wizard. This example will make use of the glucose sensor project in "wireless_examples -> bluetooth -> glucose_s -> freertos -> glucose_sensor_freertos". See the picture below. 2- Navigate to "Project -> Properties -> C/C++ Build -> MCU settings -> Memory details". Edit the Flash fields as shown in the figure below, and leave intact the RAM. The last fields indicate to the linker file that the image must be addressed after the first flash sector, to do not overwrite the OTAP bootloader software, as we stated in the introduction of this post. 3- Unzip your KW38 SDK package. Drag and drop the "main_text_section.ldt" linker script from the following path to the "linkscripts" folder on your workspace. The result must be similar as shown in the following figure. <KW38_SDK>\middleware\wireless\framework\Common\devices\MKW38A4\mcux\linkscript_bootloader\main_text_section.ldt 4- Open the "end_text.ldt" linker script file located in the linkscripts folder in MCUXpresso IDE. Locate the section shown in the following figure and remove "FILL" and "BYTE" statements. BYTE and FILL lines are used to fill with a 0xFF pattern the unused NVM flash memory region. Removing this code, our software image will not contain this pattern, in consequence, the image reduces its total size and it improves the speed of the OTAP download and memory usage. 5- Open the "app_preinclude.h" file, and define "gEepromType_d" as internal storage. This is a dummy definition needed to place the bootloader flags in the proper address, so this will not affect the storage method chosen before when you programmed the OTAP client and the OTAP bootloader software in your MCU. /* Specifies the type of EEPROM available on the target board */ #define gEepromType_d gEepromDevice_InternalFlash_c 6-  Include in your project, the "OtaSupport" folder and its files in the "framework" folder of your project. Include as well the "External" folder and its files in the "framework -> Flash" folder of your project. "OtaSupport" and "External" folders can be found in your SDK. You can easily drag those folders from your SDK download path and drop it into your workspace in MCUXpresso to include them. "OtaSupport" and "External" folders are located at: OtaSupport <KW38_SDK>middleware\wireless\framework\OtaSupport External <KW38_SDK>middleware\wireless\framework\Flash\External The result must look like the following picture:  7- Go to "Project -> Properties -> C/C++ Build -> Settings -> Tool Settings -> MCU C Compiler -> Includes". Click on the icon next to "Include paths" (See the picture below). A new window will be displayed, then click on the "Workspace" button. 8- Deploy the directory of the project in the "Folder selection" window, and select "framework -> Flash -> External -> interface" and "framework -> OtaSupport -> interface" folders. Click the "OK" button to save the changes. 9- Ensure that "OtaSupport" and "External" folders were imported in the "Include paths" window. Then save the changes by clicking on the "Apply and Close" button. 10- Save and build the project by clicking this icon  . Then, deploy the "Binaries" icon in your project. Click the right mouse button on the ".axf" file and select the "Binary Utilities -> Create S-Record" option. The S-Record file generated will be saved in the Debug folder in your workspace with ".s19" extension. Save the S-Record file in a known location on your smartphone.    Testing the OTAP Client with IoT Toolbox App This section explains how to test the OTAP client software using the IoT Toolbox App. 1- Open the IoT Toolbox App on your smartphone. Select OTAP and click "SCAN" to start scanning for a suitable OTAP Client device.  2- Press the ADV button (SW2) on your FRDM-KW38 board to start advertising. 3- Once your smartphone has found the FRDM-KW38 board, it will be identified as "NXP_OTAA". Connect your smartphone with this device. Then a new window will be displayed on your smartphone.  4- Click the "Open" button and search for the SREC software update. 5- Click "Upload" to start the transfer. Wait while the download is completed. A confirmation message will be displayed after a successful update.  6- Wait a few seconds until the software update was programmed on your MCU. The new code will start automatically.   Please let me know any questions about this topic.

Bluetooth® Low-Energy (BLE) RF PHY tests can be done by using the Direct Test Mode (DTM).  This document will help as a guide to perform the test using a device from the KW family.     Direct Test Mode Direct Test Mode (DTM) is used to control the Device Under Test (DUT) and provides a report with the results from the tests performed by the Tester.   There are two ways to perform those tests:   HCI Through a 2-wire UART interface   The packet format from the DTM is different from the HCI commands.   For further information of the commands and this type of tests, please refer to the Bluetooth Core Specifications, Vol 6, Part F: Direct Test Mode   Software This guide will use the KW41Z as example, but the same changes must be applicable for the rest of the devices Download and install the software SDK of the device to use by following the getting started in the device page. In this case the SDK of the KW41Z will be downloaded from the MCUXpresso Builder. Setup for DTM using HCI Import the hci_black_box example to the IDE according to the getting started of the device.   Download and open the latest version of the Test Tool available in the page of the device under Lab & Test Software in the Software and Tools Tab. Open the Command console of the board, please be sure that you have the correct baud rate set for the example (Default: 115200) Select one of the available commands to either start or finish tests    Setup for DTM using DTM pins You can choose from any example available while making sure that the pins chosen for DTM  are not occupied or used. Import the beacon example to the IDE according to the getting started of the device.   The DTM pins behave as a UART interface; in order to enable them in our KW devices there is the need to follow the next steps Look at the Reference manual of the device and locate the pins that support the DTM_TX and the DTM_RX. In this case, we will select the PTB1 and PTB2.  Set the ALT_MUX of the pin in the code to work as DTM   PORT_SetPinMux(PORTB, PIN1_IDX, kPORT_MuxAlt2);            /* PORTB1 (pin 17) is configured as DTM_RX */   PORT_SetPinMux(PORTB, PIN2_IDX, kPORT_MuxAlt3);            /* PORTB2 (pin 18) is configured as DTM_TX */‍‍‍‍‍‍‍‍‍‍ Configure the baud rate of the DTM pins, this can be achieved by writing to the DTM_2WIRE_CONFIG register. This register is not available in the header file by default, so there is the need to create a pointer to such address. To verify this data, you can check the chapter 45.2.3.1.4 Test and Debug Registers Descriptions for the Bluetooth Link Layer of the reference manual. #define DTM_2WIRE_CONFIG                0x580 #define BTLE_RF_DTM_2WIRE_CONFIG        (*(volatile uint16_t *) (BTLE_RF_BASE+DTM_2WIRE_CONFIG)) BTLE_RF_DTM_2WIRE_CONFIG = 0x0042;  /*Configure DTM pins baud rate of 115200*/‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

I got a question related to best practices to configure a GPIO if the pin is not used. To make it short, the recommendation is to leave the GPIO floating on the PCB and leave the GPIO in its "Default" state as shown in the Signal Multiplexing table in the Reference Manual. The Default state is either “Disabled” or an analog function.   Some Kinetis devices have analog only pins (PGAx/ADCx) while most have GPIO pins with analog functions (PTx/ADCx) or digital GPIO pins   Unused pins, whether analog only or GPIO, should be left floating. Analog only pins do not have input buffers that will cause shoot-through currents when the input floats. GPIO pins with analog functions default to analog functions, which disables the digital input buffer – no shoot-through current.   The digital GPIO pins default to "Disabled", which disables the input buffers - no shoot-through currents with floating inputs.   Finally, unused pins shall not be tied to VDD or VSS. Hence, when designing your board and there are some unused pins, leave them floating on the PCB and then make sure that the software leaves the GPIO in its Default state in the MUX register. 

This guide will show a way to set up and enable an I2C Serial Interface to send a string of data instances using one of the Wireless Bluetooth SDK examples and the Serial Manager API.

Introduction When a Bluetooth LE Central and Peripheral devices are in connection, data within the payload can be encrypted. Encryption of the channel can be achieved through pairing with others. Once the communication has been encrypted, the Bluetooth LE devices could distribute the keys to save it for future connections. The last is better known as bonding. When two Bluetooth LE devices are bonded, in a future connection, they do not need to exchange the keys since they already know the shared secret, thus, they can encrypt the channel directly, saving time and power. However, if an attacker is listening to the first time that both (Central and Peripheral) Bluetooth LE devices enter into a connection state, the security of the link could be vulnerated, since the attacker could decipher the original message. Fortunately, Out Of Band (OOB) provides the ability (obviously, if both devices support it) to share the keys on an unknown medium for an attacker listening Bluetooth LE (for instance, NFC, SPI, UART, CAN, etc), increasing the security of the communication. This document explains how to enable OOB pairing on Bluetooth LE connectivity examples, basing on FRDM-KW36 SDK HID Host and HID Device examples.   Dedicated Macros and APIs for OOB Pairing The connectivity software stack contains macros and APIs that developers should implement to interact with the host stack and handle the events necessary for OOB. The following sections explain the main macros, variables, and APIs that manage OOB in our software.   Definitions and Variables gAppUsePairing_d It is used to enable or disable pairing to encrypt the link. Values Result 0 Pairing Disabled 1 Pairing Enabled   gAppUseBonding_d It is used to enable or disable bonding to request and save the keys for future connections. Values Result 0 Bonding Disabled 1 Bonding Enabled   gBleLeScOobHasMitmProtection_c This flag must be set if the application requires Man In the Middle protection, in other words, if the link must be authenticated. You can determine whether your software needs to set or clear this flag from the GAP Security Mode and Level. Red instances of the following table indicate that gBleLeScOobHasMitmProtection_c must be set to 1.   gPairingParameters This struct contains the pairing request or the pairing response (depending on the device's GAP role) payload. To enable and configure OOB pairing, oobAvailable field of the struct must be set to 1.   APIs bleResult_t Gap_ProvideOob (deviceId_t deviceId, uint8_t* aOob) This API must be implemented in response of gConnEvtOobRequest_c event in BleConnManager_GapPeripheralEvent or BleConnManager_GapCentralEvent functions (depending of the GAP role). This event only will be triggered if OOB is enabled and LE Legacy pairing is used. The gConnEvtOobRequest_c event occurs when the stack request the OOB data received from the peer device just after the gConnEvtPairingRequest_c or gConnEvtPairingResponse_c (depending of the GAP role). This API is valid only for LE Legacy pairing. Name of the Parameter Input/Output Description deviceId Input ID of the peer device aOob Input Pointer to OOB data previously received from the peer.   bleResult_t Gap_LeScGetLocalOobData (void) This API must be implemented either in response of gConnEvtPairingRequest_c or gConnEvtPairingResponse_c events  in BleConnManager_GapPeripheralEvent or BleConnManager_GapCentralEvent functions (depending of the GAP role) to get the local OOB data generated from the controller and in response of gLeScPublicKeyRegenerated_c event at BleConnManager_GenericEvent. Each time that Gap_LeScGetLocalOobData is executed in the application to obtain the OOB data, it triggers the gLeScLocalOobData_c generic event to inform that OOB data must be read from pGenericEvent->eventData.localOobData to send it to the peer device. This API is valid only for LE Secure Connections pairing.   bleResult_t Gap_LeScSetPeerOobData (deviceId_t deviceId, gapLeScOobData_t* pPeerOobData) This API must be implemented in response of gConnEvtLeScOobDataRequest_c event in BleConnManager_GapPeripheralEvent or BleConnManager_GapCentralEvent functions(depending of the GAP role). This event occurs when the stack requires the OOB data previously recieved from the peer. This API is valid only for LE Secure Connections pairing. Name of the Parameter Input/Output Description deviceId Input ID of the peer device aOob Input Pointer to gapLeScOobData_t struct that contains the OOB data received from the peer.   Enabling OOB on KW36 Bluetooth LE Peripheral Device The following example is based on the HID Device software included in the FRDM-KW36 SDK. It explains the minimum code needed to enable OOB. In the following sections, brown color indicates that such definition or API takes part in the stack and violet color indicates that such definition does not take part in the stack and its use is only for explanation purposes in this document.   Changes in app_preinclude.h file The app_preinclude.h header file contains definitions for the management of the application. To enable OOB pairing, you must ensure that gAppUseBonding_d and gAppUsePairing_d are set to 1. You can also set the value of the gBleLeScOobHasMitmProtection_c in this file, depending on the security mode and level needed in your application.  This example makes use of two custom definitions: gAppUseOob_d and gAppUseSecureConnections_d. Such definitions are used to explain how to enable/disable OOB and, if OOB is enabled, how to switch between LE Secure Connections pairing or LE Legacy paring.   /*! Enable/disable use of bonding capability */ #define gAppUseBonding_d 1 /*! Enable/disable use of pairing procedure */ #define gAppUsePairing_d 1 /*! Enable/disable use of privacy */ #define gAppUsePrivacy_d 0 #define gPasskeyValue_c 999999 /*! Enable/disable use of OOB pairing */ #define gAppUseOob_d 1 /*! Enable MITM protection when using OOB pairing */ #if (gAppUseOob_d) #define gBleLeScOobHasMitmProtection_c TRUE #endif /*! Enable/disable Secure Connections */ #define gAppUseSecureConnections_d 1‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Using the code above, you can enable or disable OOB using gAppUseOob_d, also you can decide whether to use LE Secure Connections (gAppUseSecureConnections_d = 1) or LE Legacy (gAppUseSecureConnections_d = 0)     Changes in app_config.c file The following portion fo code depicts how to fill gPairingParameters struct depending on which pairing method is used by the application.   /* SMP Data */ gapPairingParameters_t gPairingParameters = { .withBonding = (bool_t)gAppUseBonding_d, /* If Secure Connections pairing is supported, then set Security Mode 1 Level 4 */ /* If Legacy pairing is supported, then set Security Mode 1 Level 3 */ #if (gAppUseSecureConnections_d) .securityModeAndLevel = gSecurityMode_1_Level_4_c, #else .securityModeAndLevel = gSecurityMode_1_Level_3_c, #endif .maxEncryptionKeySize = mcEncryptionKeySize_c, .localIoCapabilities = gIoKeyboardDisplay_c, /* OOB Available enabled when app_preinclude.h file gAppUseOob_d macro is true */ .oobAvailable = (bool_t)gAppUseOob_d, #if (gAppUseSecureConnections_d) .centralKeys = (gapSmpKeyFlags_t) (gIrk_c), .peripheralKeys = (gapSmpKeyFlags_t) (gIrk_c), #else .centralKeys = (gapSmpKeyFlags_t) (gLtk_c | gIrk_c), .peripheralKeys = (gapSmpKeyFlags_t) (gLtk_c | gIrk_c), #endif /* Secure Connections enabled when app_preinclude.h file gAppUseSecureConnections_d macro is true */ .leSecureConnectionSupported = (bool_t)gAppUseSecureConnections_d, .useKeypressNotifications = FALSE, };‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Additionally, the serviceSecurity struct registers which are the security mode and level of each Bluetooth LE service, so if Secure Connections is selected (gAppUseSecureConnections_d = 1), mode = 1 level = 4.   static const gapServiceSecurityRequirements_t serviceSecurity[3] = { { .requirements = { #if (gAppUseSecureConnections_d) .securityModeLevel = gSecurityMode_1_Level_4_c, #else .securityModeLevel = gSecurityMode_1_Level_3_c, #endif .authorization = FALSE, .minimumEncryptionKeySize = gDefaultEncryptionKeySize_d }, .serviceHandle = (uint16_t)service_hid }, { .requirements = { #if (gAppUseSecureConnections_d) .securityModeLevel = gSecurityMode_1_Level_4_c, #else .securityModeLevel = gSecurityMode_1_Level_3_c, #endif .authorization = FALSE, .minimumEncryptionKeySize = gDefaultEncryptionKeySize_d }, .serviceHandle = (uint16_t)service_battery }, { .requirements = { #if (gAppUseSecureConnections_d) .securityModeLevel = gSecurityMode_1_Level_4_c, #else .securityModeLevel = gSecurityMode_1_Level_3_c, #endif .authorization = FALSE, .minimumEncryptionKeySize = gDefaultEncryptionKeySize_d }, .serviceHandle = (uint16_t)service_device_info } };‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     Changes in ble_conn_manager.c file LE Legacy Pairing If your application will use LE Legacy Pairing, then you have to implement Gap_ProvideOob in response to the gConnEvtOobRequest_c event at the BleConnManager_GapPeripheralEvent function. In this example, gOobReceivedTKDataFromPeer is an array that stores the data previously received OOB from the peer device (using SPI, UART, I2C, etc), therefore, the procedure to fill this array with the data received from the peer depends entirely on your application. Notice that gOobReceivedTKDataFromPeer must contain the data received from the peer before to execute Gap_ProvideOob.   static uint8_t gOobReceivedTKDataFromPeer[16]; void BleConnManager_GapPeripheralEvent(deviceId_t peerDeviceId, gapConnectionEvent_t* pConnectionEvent) { switch (pConnectionEvent->eventType) { case gConnEvtConnected_c: { ... ... ... } break; ... ... ... #if (gAppUseOob_d && !gAppUseSecureConnections_d) case gConnEvtOobRequest_c: { /* The stack has requested the LE Legacy OOB data*/ (void)Gap_ProvideOob(peerDeviceId, &gOobReceivedTKDataFromPeer[0]); } break; #endif ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     LE Secure Connections Pairing When using Secure Connections Pairing, the application must handle two events at the BleConnManager_GapPeripheralEvent function. In gConnEvtPairingRequest_c event, you must implement Gap_LeScGetLocalOobData API to generate the local (r, Cr) values. The gConnEvtLeScOobDataRequest_c event indicates that the application is requesting the (r, Cr) values previously received OOB from the peer device (using SPI, UART, I2C, etc). Such values are contained into gOobReceivedRandomValueFromPeer and gOobReceivedConfirmValueFromPeer buffers. You must implement Gap_LeScSetPeerOobData in response to gConnEvtLeScOobDataRequest_c, This function has two parameters, the device ID of the peer and a pointer to a gapLeScOobData_t type struct. This struct is filled with the data contained in gOobReceivedRandomValueFromPeer and gOobReceivedConfirmValueFromPeer buffers.   gapLeScOobData_t gPeerOobData; static uint8_t gOobReceivedRandomValueFromPeer[gSmpLeScRandomValueSize_c]; /*!< LE SC OOB r (Random value) */ static uint8_t gOobReceivedConfirmValueFromPeer[gSmpLeScRandomConfirmValueSize_c]; /*!< LE SC OOB Cr (Random Confirm value) */ void BleConnManager_GapPeripheralEvent(deviceId_t peerDeviceId, gapConnectionEvent_t* pConnectionEvent) { switch (pConnectionEvent->eventType) { case gConnEvtConnected_c: { ... ... ... } break; case gConnEvtPairingRequest_c: { #if (defined(gAppUsePairing_d) && (gAppUsePairing_d == 1U)) gPairingParameters.centralKeys = pConnectionEvent->eventData.pairingEvent.centralKeys; (void)Gap_AcceptPairingRequest(peerDeviceId, &gPairingParameters); #if (gAppUseOob_d && gAppUseSecureConnections_d) /* The central has requested pairing, get local LE Secure Connections OOB data */ (void)Gap_LeScGetLocalOobData(); #endif #else (void)Gap_RejectPairing(peerDeviceId, gPairingNotSupported_c); #endif } break; ... ... ... #if (gAppUseOob_d && gAppUseSecureConnections_d) case gConnEvtLeScOobDataRequest_c: { /* The stack has requested the peer LE Secure Connections OOB data. Fill the gPeerOobData struct and provide it to the stack */ FLib_MemCpy(gPeerOobData.randomValue, &gOobReceivedRandomValueFromPeer[0], gSmpLeScRandomValueSize_c); FLib_MemCpy(gPeerOobData.confirmValue, &gOobReceivedConfirmValueFromPeer[0], gSmpLeScRandomConfirmValueSize_c); Gap_LeScSetPeerOobData(peerDeviceId, &gPeerOobData); } break; #endif ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   The gLeScPublicKeyRegenerated_c event in the BleConnManager_GenericEvent function must be handled using the Gap_LeScGetLocalOobData API as depicted below. Each time that Gap_LeScGetLocalOobData is executed by the software, it generates, asynchronously, the gLeScLocalOobData_c event (also handled in the BleConnManager_GenericEvent function) indicating that the local (r, Cr) values were successfully generated and you can read them using the pGenericEvent->eventData.localOobData pointer to send it OOB to the peer device. In this example, Oob_SendLocalRandomValueToPeer and Oob_SendLocalConfirmValueToPeer  are custom synchronous functions that demonstrate how you can implement a custom API that sends the local (r, Cr) read from pGenericEvent->eventData.localOobData pointer to the peer device using other protocols (SPI, UART, I2C, etc).   void BleConnManager_GenericEvent(gapGenericEvent_t* pGenericEvent) { switch (pGenericEvent->eventType) { case gInitializationComplete_c: { ... ... ... } break; ... ... ... #if (defined(gAppUsePairing_d) && (gAppUsePairing_d == 1U)) case gLeScPublicKeyRegenerated_c: { /* Key pair regenerated -> reset pairing counters */ mFailedPairings = mSuccessfulPairings = 0; /* Local Secure Connections OOB data must be refreshed whenever this event occurs */ #if (gAppUseOob_d && gAppUseSecureConnections_d) (void)Gap_LeScGetLocalOobData(); #endif } break; #endif ... ... ... #if (gAppUseOob_d && gAppUseSecureConnections_d) case gLeScLocalOobData_c: { /* Get the local Secure Connections OOB data and send to the peer */ Oob_SendLocalRandomValueToPeer((uint8_t*)pGenericEvent->eventData.localOobData.randomValue); Oob_SendLocalConfirmValueToPeer((uint8_t*)pGenericEvent->eventData.localOobData.confirmValue); } break; #endif ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     Enabling OOB on KW36 Bluetooth LE Central Device The following example is based on the HID Host software included in the FRDM-KW36 SDK. It explains the minimum code needed to enable OOB. In the following sections, brown color indicates that such definition or API takes part in the stack and violet color indicates that such definition does not take part in the stack and its use is only for explanation purposes in this document.   Changes in app_preinclude.h file The app_preinclude.h header file contains definitions for the management of the application. To enable OOB pairing, you must ensure that gAppUseBonding_d and gAppUsePairing_d are set to 1. You can also set the value of the gBleLeScOobHasMitmProtection_c in this file, depending on the security mode and level needed in your application.  This example makes use of two custom definitions: gAppUseOob_d and gAppUseSecureConnections_d. Such definitions are used to explain how to enable/disable OOB and, if OOB is enabled, how to switch between LE Secure Connections pairing or LE Legacy paring.   /*! Enable/disable use of bonding capability */ #define gAppUseBonding_d 1 /*! Enable/disable use of pairing procedure */ #define gAppUsePairing_d 1 /*! Enable/disable use of privacy */ #define gAppUsePrivacy_d 0 #define gPasskeyValue_c 999999 /*! Enable/disable use of OOB pairing */ #define gAppUseOob_d 1 /*! Enable MITM protection when using OOB pairing */ #if (gAppUseOob_d) #define gBleLeScOobHasMitmProtection_c TRUE #endif /*! Enable/disable Secure Connections */ #define gAppUseSecureConnections_d 1‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Using the code above, you can enable or disable OOB using gAppUseOob_d, also you can decide whether to use LE Secure Connections (gAppUseSecureConnections_d = 1) or LE Legacy (gAppUseSecureConnections_d = 0)     Changes in app_config.c file The following portion fo code depicts how to fill gPairingParameters struct depending on which pairing method is used by the application.   /* SMP Data */ gapPairingParameters_t gPairingParameters = { .withBonding = (bool_t)gAppUseBonding_d, /* If Secure Connections pairing is supported, then set Security Mode 1 Level 4 */ /* If Legacy pairing is supported, then set Security Mode 1 Level 3 */ #if (gAppUseSecureConnections_d) .securityModeAndLevel = gSecurityMode_1_Level_4_c, #else .securityModeAndLevel = gSecurityMode_1_Level_3_c, #endif .maxEncryptionKeySize = mcEncryptionKeySize_c, .localIoCapabilities = gIoKeyboardDisplay_c, /* OOB Available enabled when app_preinclude.h file gAppUseOob_d macro is true */ .oobAvailable = (bool_t)gAppUseOob_d, #if (gAppUseSecureConnections_d) .centralKeys = (gapSmpKeyFlags_t) (gIrk_c), .peripheralKeys = (gapSmpKeyFlags_t) (gIrk_c), #else .centralKeys = (gapSmpKeyFlags_t) (gLtk_c | gIrk_c), .peripheralKeys = (gapSmpKeyFlags_t) (gLtk_c | gIrk_c), #endif /* Secure Connections enabled when app_preinclude.h file gAppUseSecureConnections_d macro is true */ .leSecureConnectionSupported = (bool_t)gAppUseSecureConnections_d, .useKeypressNotifications = FALSE, };‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     Changes in ble_conn_manager.c file LE Legacy Pairing If your application will use LE Legacy Pairing, then you have to implement Gap_ProvideOob in response to the gConnEvtOobRequest_c event at the BleConnManager_GapCentralEvent function. In this example, gOobOwnTKData is an array that stores the TK data which will be sent OOB to the peer device (using SPI, UART, I2C, etc)  and, at the same time, is the TK data that will be provided to the stack using Gap_ProvideOob. This data must be common on both Central and Peripheral devices, so the procedure to share the TK depends entirely on your application. Oob_SendLocalTKValueToPeer is a custom synchronous function that demonstrates how you can implement a custom API that sends the local TK to the peer device using other protocols (SPI, UART, I2C, etc).   static uint8_t gOobOwnTKData[16] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F}; void BleConnManager_GapCentralEvent(deviceId_t peerDeviceId, gapConnectionEvent_t* pConnectionEvent) { switch (pConnectionEvent->eventType) { case gConnEvtConnected_c: { ... ... ... } break; ... ... ... case gConnEvtPairingResponse_c: { /* Send Legacy OOB data to the peer */ #if (gAppUseOob_d & !gAppUseSecureConnections_d) Oob_SendLocalTKValueToPeer(&gOobOwnTKData[0]); #endif } break; ... ... ... #if (gAppUseOob_d && !gAppUseSecureConnections_d) case gConnEvtOobRequest_c: { /* The stack has requested the LE Legacy OOB data*/ (void)Gap_ProvideOob(peerDeviceId, &gOobOwnTKData[0]); } break; #endif‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     LE Secure Connections Pairing When using Secure Connections Pairing, the application must handle two events at the BleConnManager_GapCentralEvent function. In gConnEvtPairingResponse_c event, you must implement Gap_LeScGetLocalOobData API to generate the local (r, Cr) values. The gConnEvtLeScOobDataRequest_c event indicates that the application is requesting the (r, Cr) values previously received OOB from the peer device (using SPI, UART, I2C, etc). Such values are contained into gOobReceivedRandomValueFromPeer and gOobReceivedConfirmValueFromPeer buffers. You must implement Gap_LeScSetPeerOobData in response to gConnEvtLeScOobDataRequest_c, This function has two parameters, the device ID of the peer and a pointer to a gapLeScOobData_t type struct. This struct is filled with the data contained in gOobReceivedRandomValueFromPeer and gOobReceivedConfirmValueFromPeer buffers.   gapLeScOobData_t gPeerOobData; static uint8_t gOobReceivedRandomValueFromPeer[gSmpLeScRandomValueSize_c]; /*!< LE SC OOB r (Random value) */ static uint8_t gOobReceivedConfirmValueFromPeer[gSmpLeScRandomConfirmValueSize_c]; /*!< LE SC OOB Cr (Random Confirm value) */ void BleConnManager_GapCentralEvent(deviceId_t peerDeviceId, gapConnectionEvent_t* pConnectionEvent) { switch (pConnectionEvent->eventType) { case gConnEvtConnected_c: { ... ... ... } break; ... ... ... case gConnEvtPairingResponse_c: { /* The peripheral has acepted pairing, get local LE Secure Connections OOB data */ #if (gAppUseOob_d && gAppUseSecureConnections_d) (void)Gap_LeScGetLocalOobData(); #endif } break; ... ... ... #if (gAppUseOob_d && gAppUseSecureConnections_d) case gConnEvtLeScOobDataRequest_c: { /* The stack has requested the peer LE Secure Connections OOB data. Fill the gPeerOobData struct and provide it to the stack */ FLib_MemCpy(gPeerOobData.randomValue, &gOobReceivedRandomValueFromPeer[0], gSmpLeScRandomValueSize_c); FLib_MemCpy(gPeerOobData.confirmValue, &gOobReceivedConfirmValueFromPeer[0], gSmpLeScRandomConfirmValueSize_c); Gap_LeScSetPeerOobData(peerDeviceId, &gPeerOobData); } break; #endif ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   The gLeScPublicKeyRegenerated_c event in the BleConnManager_GenericEvent function must be handled using the Gap_LeScGetLocalOobData API as depicted below. Each time that Gap_LeScGetLocalOobData is executed by the software, it generates, asynchronously, the gLeScLocalOobData_c event (also handled in the BleConnManager_GenericEvent function) indicating that the local (r, Cr) values were successfully generated and you can read them using the pGenericEvent->eventData.localOobData pointer to send it OOB to the peer device. In this example, Oob_SendLocalRandomValueToPeer and Oob_SendLocalConfirmValueToPeer  are custom synchronous functions that demonstrate how you can implement a custom API that sends the local (r, Cr) read from pGenericEvent->eventData.localOobData pointer to the peer device using other protocols (SPI, UART, I2C, etc).   void BleConnManager_GenericEvent(gapGenericEvent_t* pGenericEvent) { switch (pGenericEvent->eventType) { case gInitializationComplete_c: { ... ... ... } break; ... ... ... #if (defined(gAppUsePairing_d) && (gAppUsePairing_d == 1U)) case gLeScPublicKeyRegenerated_c: { /* Key pair regenerated -> reset pairing counters */ mFailedPairings = mSuccessfulPairings = 0; /* Local LE Secure Connections OOB data must be refreshed whenever this event occurs */ #if (gAppUseOob_d && gAppUseSecureConnections_d) (void)Gap_LeScGetLocalOobData(); #endif } break; #endif ... ... ... #if (gAppUseOob_d && gAppUseSecureConnections_d) case gLeScLocalOobData_c: { /* Get the local LE Secure Connections OOB data and send to the peer */ Oob_SendLocalRandomValueToPeer((uint8_t*)pGenericEvent->eventData.localOobData.randomValue); Oob_SendLocalConfirmValueToPeer((uint8_t*)pGenericEvent->eventData.localOobData.confirmValue); } break; #endif ... ... ... } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍     Simplified Flow Diagram of OOB Central and Peripheral Events LE Legacy Pairing The following figure shows a simplified flow diagram of the LE Legacy OOB pairing example in this document. The LE Central device is the one that contains the OOB TK data that will be shared OOB using the custom Oob_SendLocalTKValueToPeer function. It must be implemented at the gConnEvtPairingResponse_c event to ensure that both devices know the OOB TK before to execute Gap_ProvideOob since this function requests this data. If the OOB data is correct on both sides, the pairing procedure ends, and it is noticed through gConnEvtPairingComplete_c. LE Secure Connections Pairing The following figure shows a simplified flow diagram of the LE Secure Connections OOB pairing example in this document. After both devices enter in connection, the data that will be shared OOB using the custom Oob_SendLocalRandomValueToPeer and Oob_SendLocalConfirmValueToPeer  functions is yielded by Gap_LeScGetLocalOobData on both sides. The last one must be implemented at gConnEvtPairingResponse_c and gConnEvtPairingRequest_c events to ensure that both devices know the Peripheral and Central (r, Cr) OOB data before to execute Gap_LeScSetPeerOobData since this function requests this data. If the OOB data is correct on both sides, the pairing procedure ends, and it is noticed through gConnEvtPairingComplete_c. This is how OOB pairing can be implemented in your project. I hope this document will be useful to you. Please, let us know any questions or comments. 

Thread is a secure, wireless, simplified IPv6-based mesh networking protocol developed by industry leading technology companies, including Freescale, for connecting devices to each other, to the internet and to the cloud. Before starting a Thread Network implementation, users should be familiar with some concepts and how they are related to Thread protocol. IPv6 Addressing Devices in the Thread stack support IPv6 addressing IPv6 addresses are 128-bit identifiers (IPv4 is only 32-bit) for interfaces and sets of interfaces.  Thread supports the following types of addresses: Unicast:  An identifier for a single interface.  A packet sent to a unicast address is delivered to the interface identified by that address. Multicast: An identifier for a set of interfaces (typically belonging to different nodes).  A packet sent to a multicast address is delivered to all interfaces identified by that address. NOTES There are no broadcast addresses in IPv6, their function being superseded by multicast addresses. Each device joining the Thread Network is also assigned a 16-bit short address as specified in IEEE 802.15.4. 6LoWPAN All Thread devices use 6LoWPAN 6LoWPAN stands for “IPv6 over Low Power Wireless Personal Networks”. 6LoWPAN is a set of standards defined by the Internet Engineering Task Force (IETF), which enables the efficient use of IPv6 over low-power, low-rate wireless networks on simple embedded devices through an adaptation layer and the optimization of related protocols. Its main goal is to send/receive IPv6 packets over 802.15.4 links. Next figure compares IP and 6LoWPAN protocol stacks: The following concepts would explain the transport layer. ICMP Thread devices support the ICMPv6 (Internet Control Message Protocol version 6) protocol and ICMPv6 error messages, as well as the echo request and echo reply messages. The Internet Control Message Protocol (ICMP) is an error reporting and diagnostic utility and is considered a required part of any IP implementation. ICMPs are used by routers, intermediary devices, or hosts to communicate updates or error information to other routers, intermediary devices, or hosts. For instance, ICMPv6 is used by IPv6 nodes to report errors encountered in processing packets, and to perform other internet-layer functions, such as diagnostics. ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems, nor is it regularly employed by end-user network applications.  The ICMPv6 messages have the following general format: The type field indicates the type of the message.  Its value determines the format of the remaining data. The code field depends on the message type.  It is used to create an additional level of message granularity. The checksum field is used to detect data corruption in the ICMPv6 message and parts of the IPv6 header. ICMPv6 messages are grouped into two classes: error messages and informational messages.  Error messages are identified as such by a zero in the high-order bit of their message Type field values.  Thus,   error messages have message types from 0 to 127; informational messages have message types from 128 to 255. UDP The Thread stack supports UDP for messaging between devices. This User Datagram Protocol  (UDP)  is defined  to  make available  a datagram   mode of  packet-switched   computer communication  in  the environment  of an  interconnected  set  of  computer  networks, assuming that the Internet  Protocol (IP) is used as the underlying protocol. With UDP, applications can send data messages to other hosts on an IP network without prior communications to set up special transmission channels or data paths. UDP is suitable for purposes where error checking and correction is either not necessary or is performed in the application, avoiding the overhead of such processing at the network interface level. The UDP format is as follows: Source Port is an optional field, when meaningful, it indicates the port of the sending  process,  and may be assumed  to be the port  to which a reply should be addressed  in the absence of any other information.  If not used, a value of zero is inserted. Destination Port has a meaning within the context of a particular internet destination address. Length is the length in octets of this user datagram including this header and the data.   (This means the minimum value of the length is eight.) Checksum is the 16-bit one's complement of the one's complement sum of a pseudo header of information from the IP header, the UDP header, and the data, padded  with zero octets at the end (if  necessary)  to  make  a multiple of two octets. References White papers available at http://threadgroup.org/ “6LoWPAN: The Wireless Embedded Internet” by Zach Shelby and Carsten Bromann RFC 4291, RFC 4944, RFC 4443 and RFC 768 from https://www.ietf.org

FRDM-KW36 Software Development Kit (SDK) includes drivers and examples of FlexCAN module for KW36 which can be easily configured for a custom communication. For example, if user want to change the default baud rate from FlexCAN driver demo examples then the only needed change is the default value on "config->baudRate" and "config->baudRateFD" from "FLEXCAN_GetDefaultConfig" function (See Figure 1). Segments within a bit time will be automatically configured to obtain the desired baud rate. By default, demos are configured to work with CAN FD communication. Figure 1. FRDM-KW36's default baudrate from flexcan_interrupt_transfer driver example Even so, there are cases where segments within a bit time are not well configured and it's necessary that user configure segments manually. An example occurs by setting the maximum FD baud rate "3.2MHz" using the 32MHz xtal or "2.6MHz" using a 26MHz xtal where demo reports an error. See Figure 2. Figure 2. Error by setting maximum baud rate When this error occurs, the fix is on setting the timing config parameters correctly by including the definition of SET_CAN_QUANTUM on application source file (see Figure 3) and then declare and initialize the timing config parameters shown in Figure 4. Figure 3. SET_CAN_QUANTUM define Figure 4. Custom timing config parameters For this example we are going to show how to calculate timing config parameters in an scenario where a CAN FD communication is used with baud rate of 500kHz on nominal phase and 3.2MHz on FD phase. See Figure 5.  To do it, we need to calculate Time Quanta and value of segments within the bit time.    Figure 5. Custom CAN FD baudrate KW36 Reference Manual in chapter "37.4.8.7 Protocol timing" shows the segments within a bit time for CAN nominal phase configured in "CAN_CTRL1" register (see Figure 6), and segments for FD phase configured in CAN_FDCBT register (see Figure 7). Figure 6. Segment within a bit time for CAN nominal phase Figure 7. Segment within a bit time for CAN FD phase Before calculating the value of segments, first we need to calculate the Time Quanta which is the atomic number of time handled by the CAN engine. The formula to calculate Time Quanta is shown in Figure 8 taken from KW36 Reference Manual. Figure 8. Time Quanta Formula CANCLK can be selected by CLKSRC bits on CAN_CTRL1 register as shown in Figure 9, where the options are Peripheral clock=20MHz or Oscillator clock (16MHz if using 32MHz xtal or 13MHz if using 26MHz xtal). The recomiendation is to use the Oscillator clock due to peripheral clock can have jitter that affect communication.  Figure 9. CAN clocks To select the Oscillator clock, search for flexcanConfig.clkSrc definition and set it to kFLEXCAN_ClkSrcOsc as shown in Figure 10. Figure 10. CANCLK selection Next step is selecting the PRESDIV value for nominal phase and FPRESDIV for FD phase. You have to select the right value to achieve the TQ needed to obtain the configured baudrate. For this example, let's set FPRESDIV value to 0 and PRESDIV value to 3. TQ calculation for nominal phase: TQ = (PRESDIV + 1) / CANCLK = (3 + 1) / 16000000 = 0.00000025 TQ calculation for FD phase: TQ = (FPRESDIV + 1) / CANCLK = (0 + 1) / 16000000 = 0.0000000625 The bit rate, which defines the rate of CAN message is given by formula shown in Figure 11 taken from KW36 Reference Manual. Figure 11. CAN Bit Time and Bit Rate Formulas With this info and with our TQ calculated, we can deduce that we need: For Nominal phase: 8 = Number of Time Quanta in 1 bit time For FD phase: 5 = Number of Time Quanta in 1 bit time Now, let's define the value of segments. For nominal phase: Bit Time =  (number of Tq in 1 bit time) x Tq CAN Bit Time = (1 + (PROPSEG + PSEG1 + 2) + (PSEG2 + 1) ) x Tq CAN Bit Time = (1 + (1 + 2  + 2) + (1 + 1) ) x Tq = 8 x 0.00000025 =  Baud rate = 1/ CAN Bit Time = 500KHz For FD phase: CAN Bit Time = (number of Tq in 1 bit time) x Tq CAN Bit Time = (1 + (FPROPSEG + FPSEG1 + 1) + (FPSEG2 + 1) ) x Tq CAN Bit Time = (1 + (0 + 1 + 1) + (1 + 1) ) x Tq = 5 x Tq =  0.0000003125 Bit Rate = 1/CAN Bit Time = 1 / 0.0000003125 =  3.2MHz To finish, just update the calculated values on your firmware on flexcanConfig.timingConfig structure.  Notes: FRDM-KW36 Software Development Kit (SDK) can be downloaded from MCUXpresso webpage. FlexCAN driver examples are located in path: "SDK_2.2.0_FRDM-KW36\boards\frdmkw36\driver_examples" from your downloaded FRDM-KW36 SDK. Take in consideration that not all the baud rates are achievables and will depend on the flexcan clock and segment values used.

This document describes how to update and sniff Bluetooth LE wireless applications on the USB-KW41 Programming the USB-KW41 as sniffer   It was noticed that there are some issues trying to follow a Bluetooth LE connection, even if the sniffer catches the connection request. These issues have been fixed in the latest binary file which can be found in the Test Tool for Connectivity Products 12.8.0.0 or newest.   After the Test Tool Installation, you’ll find the sniffer binary file at the following path. C:\NXP\Test Tool 12.8.1.0\images\KW41_802.15.4_SnifferOnUSB.bin   Programming Process. 1. Connect the USB-KW41Z to your PC, and it will be enumerated as Mass Storage Device 2. Drag and drop the "KW41_802.15.4_SnifferOnUSB.bin" included in Test tool for Connectivity Products.    "C:\NXP\Test Tool 12.8.0.0\images\KW41_802.15.4_SnifferOnUSB.bin"   3. Unplug the device and hold the RESET button of the USB-KW41Z, plug to your PC and the K22 will enter in bootloader mode. 4. Drag and drop the "sniffer_usbkw41z_k22f_0x8000.bin" included in Test tool for Connectivity Products.    "C:\NXP\Test Tool 12.8.5.9\images\sniffer_usbkw41z_k22f_0x8000.bin"   5. Then, unplug and plug the USB-KW41Z to your PC.                                                                                                          Note: If the USB-KW41 is not enumerated as Mass Storage Device, please look at the next thread https://community.nxp.com/thread/444708   General Recommendations   Software Tools  Kinetis Protocol Analyzer Wireshark version (2.4.8) Hardware Tools 1 USB-KW41 (updated with KW41_802.15.4_SnifferOnUSB.bin from Test Tool 12.8 or later)   The Kinetis Protocol Analyzer provides the ability to monitor the Bluetooth LE Advertisement Channels. It listens to all the activity and follows the connection when capturing a Connection Request.   Bluetooth LE Peripheral device transmits packets on the 3 advertising channels one after the other, so the USB-KW41 will listen to the 3 channels one by one and could or not catch the connection request.   Common use case The USB-KW41 will follow the Bluetooth LE connection if the connection request happens on the same channel that It is listening. If is listening to a different channel when the connection request is sent, it won't be able to follow it.   A Simple recommendation is the Bluetooth LE Peripheral should be set up to send the adv packets only to one channel and the sniffer just capturing on the same channel.   Improvement Use 3 USB-KW41, each of them will be dedicated to one channel and will catch the connection request.   Configure Kinetis Protocol Analyzer and Wireshark Network Analyzer   Note: For better results, address filter can be activated. When you are capturing all the packets in the air, you will notice 3 adv packets. Each packet will show the adv channel that is getting the adv frame.       One of the three sniffers will capture the Connection Request. In this case, it happens on channel 38.       You will be able to follow the connection, see all the data exchange.   For a better reference, you can look at the USB-KW41 Getting Started     Hope it helps   Regards, Mario

Introduction HCI Application is a Host Controller Interface application which provides a serial communication to interface with the KW40/KW41/KW35/KW36/QN9080 BLE radio part. It enables the user to have a way to control the radio through serial commands. The format of the HCI Command Packet it’s composed of the following parts:     Each command is assigned a 2 byte Opcode which it’s divided into two fields, called the OpCode Group Field (OGF) and OpCode Command Field (OCF). The OGF uses the upper 6 bits of the Opcode, while the OCF corresponds to the remaining 10 bits. The OGF of 0x3F is reserved for vendor-specific debug commands. The organization of the opcodes allows additional information to be inferred without fully decoding the entire Opcode. For further information regarding this topic, please check the BLUETOOTH SPECIFICATION Version 5.0 | Vol 2, Part E, 5.4 EXCHANGE OF HCI-SPECIFIC INFORMATION.   Adding HCI Custom Commands Example This document will guide you through the implementation of custom HCI commands in the KW36. For this example, we will include the following set of custom commands: 01 50 FC 00 – This command is to send a continuous unmodulated wave using a defined channel and output power (default: frequency 2.402GHz and PA_POWER register set to 0x3E).  01 4F FC 00 – This command is to stop the continuous unmodulated wave and configure the radio in Bluetooth LE mode again. This way you can continue sending adopted HCI commands. 01 00 FC 00 – Set the Channel 0 Freq 2402 MHz 01 01 FC 00 – Set the Channel 19 Freq 2440 MHz 01 02 FC 00 – Set the Channel 39 Freq 2480 MHz 01 10 FC 00 – Set the PA_POWER 1 01 11 FC 00 – Set the PA_POWER 32 01 12 FC 00 – Set the PA_POWER 62 The changes described in the following sections were based on the HCI Black Box SDK example (it is located at wireless_examples -> bluetooth -> hci_bb)   Changes in hci_transport.h The "hci_transport.h" file is located at bluetooth->hci_transport->interface folder. Include the following macros in ''Public constants and macros" #define gHciCustomCommandOpcodeUpper (0xFC50) #define gHciCustomCommandOpcodeLower (0xFC00) #define gHciInCustomVendorCommandsRange(x) (((x) <= gHciCustomCommandOpcodeUpper) && \ ((x) >= gHciCustomCommandOpcodeLower))‍‍‍‍‍‍‍‍ Declare a function to install the custom command as follows: void Hcit_InstallCustomCommandHandler(hciTransportInterface_t mCustomInterfaceHandler);‍   Changes in hcit_serial_interface.c The "hci_transport.h" file is located at bluetooth->hci_transport->source folder. Add the following in "Private memory declarations" static hciTransportInterface_t mCustomTransportInterface = NULL;‍ Modify the Hcit_SendMessage function as follows: static inline void Hcit_SendMessage(void) { uint16_t opcode = 0; /* verify if this is an event packet */ if(mHcitData.pktHeader.packetTypeMarker == gHciEventPacket_c) { /* verify if this is a command complete event */ if(mHcitData.pPacket->raw[0] == gHciCommandCompleteEvent_c) { /* extract the first opcode to verify if it is a custom command */ opcode = mHcitData.pPacket->raw[3] | (mHcitData.pPacket->raw[4] << 8); } } /* verify if command packet */ else if(mHcitData.pktHeader.packetTypeMarker == gHciCommandPacket_c) { /* extract opcode */ opcode = mHcitData.pPacket->raw[0] | (mHcitData.pPacket->raw[1] << 8); } if(gHciInCustomVendorCommandsRange(opcode)) { if(mCustomTransportInterface) { mCustomTransportInterface( mHcitData.pktHeader.packetTypeMarker, mHcitData.pPacket, mHcitData.bytesReceived); } } else { /* Send the message to HCI */ (void)mTransportInterface(mHcitData.pktHeader.packetTypeMarker, mHcitData.pPacket, mHcitData.bytesReceived); } mHcitData.pPacket = NULL; mPacketDetectStep = mDetectMarker_c; }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Develop the function to install the custom command as follows:   void Hcit_InstallCustomCommandHandler(hciTransportInterface_t mCustomInterfaceHandler) { OSA_InterruptDisable(); mCustomTransportInterface = mCustomInterfaceHandler; OSA_InterruptEnable(); }‍‍‍‍‍‍   Changes in hci_black_box.c This is the main application file, and it is located at source folder. Include the following files to support our HCI custom commands #include "hci_transport.h" #include "fsl_xcvr.h"‍‍ Define the following macros which represent the opcode for each custom command #define CUSTOM_HCI_CW_ON (0xFC50) #define CUSTOM_HCI_CW_OFF (0xFC4F) #define CUSTOM_HCI_CW_SET_CHN_0 (0xFC00) /*Channel 0 Freq 2402 MHz*/ #define CUSTOM_HCI_CW_SET_CHN_19 (0xFC01) /*Channel 19 Freq 2440 MHz*/ #define CUSTOM_HCI_CW_SET_CHN_39 (0xFC02) /*Channel 39 Freq 2480 MHz*/ #define CUSTOM_HCI_CW_SET_PA_PWR_1 (0xFC10) /*PA_POWER 1 */ #define CUSTOM_HCI_CW_SET_PA_PWR_32 (0xFC11) /*PA_POWER 32 */ #define CUSTOM_HCI_CW_SET_PA_PWR_62 (0xFC12) /*PA_POWER 62 */ #define CUSTOM_HCI_CW_EVENT_SIZE (0x04) #define CUSTOM_HCI_EVENT_SUCCESS (0x00) #define CUSTOM_HCI_EVENT_FAIL (0x01)‍‍‍‍‍‍‍‍‍‍‍ Add the following application variables static uint16_t channelCC = 2402; static uint8_t powerCC = 0x3E; uint8_t eventPacket[6] = {gHciCommandCompleteEvent_c, CUSTOM_HCI_CW_EVENT_SIZE, 1, 0, 0, 0 };‍‍‍‍‍‍ Declare the handler for our custom commands bleResult_t BleApp_CustomCommandsHandle(hciPacketType_t packetType, void* pPacket, uint16_t packetSize);‍ Find the "main_task" function, and register the handler for the custom commands through "Hcit_InstallCustomCommandHandler" function. You can include it just after BleApp_Init(); /* Initialize peripheral drivers specific to the application */ BleApp_Init(); /* Register the callback for the custom commands */ Hcit_InstallCustomCommandHandler((hciTransportInterface_t)&BleApp_CustomCommandsHandle); /* Create application event */ mAppEvent = OSA_EventCreate(TRUE); if( NULL == mAppEvent ) { panic(0,0,0,0); return; }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Develop the handler of our custom commands as follows: bleResult_t BleApp_CustomCommandsHandle(hciPacketType_t packetType, void* pPacket, uint16_t packetSize) { uint16_t opcode = 0; if(gHciCommandPacket_c == packetType) { opcode = ((uint8_t*)pPacket)[0] | (((uint8_t*)pPacket)[1] << 8); switch(opcode) { /*@CC: Set Channel */ case CUSTOM_HCI_CW_SET_CHN_0: /*@CC: Set Channel 0 Freq 2402 MHz */ channelCC=2402; break; case CUSTOM_HCI_CW_SET_CHN_19: /*@CC: Channel 19 Freq 2440 MHz*/ channelCC=2440; break; case CUSTOM_HCI_CW_SET_CHN_39: /*@CC: Channel 39 Freq 2480 MHz */ channelCC=2480; break; /*@CC: Set PA_POWER */ case CUSTOM_HCI_CW_SET_PA_PWR_1: /*@CC: Set PA_POWER 1 */ powerCC=0x01; break; case CUSTOM_HCI_CW_SET_PA_PWR_32: /*@CC: Set PA_POWER 32 */ powerCC=0x20; break; case CUSTOM_HCI_CW_SET_PA_PWR_62: /*@CC: Set PA_POWER 62 */ powerCC=0x3E; break; /*@CC: Generate a Continuous Unmodulated Signal ON / OFF */ case CUSTOM_HCI_CW_ON: /*@CC: Generate a Continuous Unmodulated Signal when pressing SW3 */ XCVR_DftTxCW(channelCC, 6); XCVR_ForcePAPower(powerCC); break; case CUSTOM_HCI_CW_OFF: /*@CC: Turn OFF the transmitter */ XCVR_ForceTxWd(); /* Initialize the PHY as BLE */ XCVR_Init(BLE_MODE, DR_1MBPS); break; default: eventPacket[5] = CUSTOM_HCI_EVENT_FAIL; break; } eventPacket[3] = (uint8_t)opcode; eventPacket[4] = (uint8_t)(opcode >> 8); eventPacket[5] = CUSTOM_HCI_EVENT_SUCCESS; Hcit_SendPacket(gHciEventPacket_c, eventPacket, sizeof(eventPacket)); } else { return gBleUnexpectedError_c; } return gBleSuccess_c; }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Testing Custom HCI Commands Using NXP Test Tool 12 To test HCI Black Box software, we need to install NXP Test Tool 12, from the NXP Semiconductors | Automotive, Security, IoT official web site. Once you have installed Test Tool, attach the FRDM-KW36 board to your PC and open the serial port enumerated in the start page clicking twice on the icon. Then, select "Raw Data" checkbox and type any of our custom commands, for instance, "01 01 FC 00" (Set the Channel 19 Freq 2440 MHz). Shift out the command clicking on the "Send Raw..." button. You will see the HCI Tx and Rx in the right upper corner of your screen

The FRDM-KW36 comes with the OpenSDA circuit which allows users to program and debug the evaluation board. There are different solutions to support such OpenSDA circuits: 1. The J-Link (SEGGER) firmware.  2. The CMSIS-DAP (mbed) firmware. The FRDM-KW36 comes pre-programmed with the CMSIS-DAP firmware. However, if you want to update the firmware version, you need to perform the next steps.  Press and hold the Reset button (SW1 push button in the board).  Unplug and plug the FRDM-KW36 again to the PC.  The board will be enumerated as "DAPLINKBOOT" device. Drag and drop the binary file to update the OpenSDA firmware.  If the J-Link version is programmed, the board will be enumerated as "FRDM-KW36J". On the other hand, if the CMSIS-DAP version is programmed, the board will be enumerated as "FRDM-KW36". The binary for the J-link version can be downloaded from the next link: SEGGER - The Embedded Experts - Downloads - J-Link / J-Trace  The binary for the CMSIS-DAP version can be found in the next link: OpenSDA Serial and Debug Adapter|NXP    Hope this helps... 

General summary MCUBOOT, fsci_bootloader and otap_bootloader are 3 different bootloader applications that can be used depending on the use case. The MCU Flashloader is a separate implementation but it's also mentioned to avoid misunderstanding.   MCUBOOT The MCU bootloader provides support for multiple communication protocols (UART, SPI, I2C, CAN) and multiple applications to interface with it. Summary: - It's a configurable flash programming utility that operates over a serial connection on several Kinetis MCUs. - Host-side command line (blhost) and GUI tools are available to communicate with the bootloader.  -  By default, application starts at address 0xa000. - MCU Bootloader|NXP website - MCU Bootloader Reference Manual - MCU Bootloader Demo Application User's Guide   fsci_bootloader Framework Serial Connectivity Interface (FSCI) is an NXP propietary protocol that allows interfacing the Kinetis protocol stack with a host system or PC tool using a serial communication interface. The FSCI bootloader enables the FSCI module to communicate with the PC and transfer the image using the FSCI protocol. Summary: - It relies on the FSCI protocol to transfer the binary from a PC connected via UART, using a python and C applications. - To enter into bootloader mode (in FRDM-KW41Z), hold SW1 (Reset) and press SW4, then release SW1 first and SW4 second. Please refer to demo user's guide to get the specific steps for your platform. - By default, application starts at 0x4000. - FSCI Bootloader Manual   otap_bootloader The Connectivity SDK contains Over-the-Air firmware upgrade examples. The OTAP bootloader loads an image obtained from wireless communication, the OTAP bootloader only enters after an image was successfully transferred to the client device (internal or external flash). Summary: - It's used by over the air programmed devices. - The bootloader mode only enters if a flag is set after reset triggered by a successful reception of an image over the air. - By default, application starts at 0x4000. - Kinetis Thread Stack Over-the-Air (OTA) Firmware Update User’s Guide   mcu_flashloader The MCU flashloader is a specific implementation of the MCU bootloader. For the flashloader implementation, the MCU bootloader command interface is packaged as an executable that is loaded from flash and executed from RAM. This configuration allows the user application to be placed at the beginning of the on-chip flash where it is automatically launched upon boot from flash. Using the MCU flashloader to program a user application to the beginning of the flash makes this implementation of the bootloader a one-time programming aid. The MCU flashloader doesn't allow to jump to a different section after a timeout or button press like the other bootloaders, it's main purpose is to flash an application without the need of an external debugger, mainly used for factory programming. Summary: - It is pre-programmed into many Kinetis flash devices during manufacturing and enables flash programming without the need for a debugger. - After the user application is programmed into flash memory, the Kinetis flashloader is no longer available. - Documentation: Getting Started with the MCU Flashloader   You can select from the MCU Bootloader, FSCI_Bootloader and OTAP Bootloader, depending on your needs. JC

Introduction The MTU (Maximum Transmission Unit) in Bluetooth LE, is an informational parameter that indicates to the remote device, the maximum number of bytes that the local can handle in such channel, for example, the ATT_MTU for KW36 is fixed in 247 bytes. A few applications require to have long characteristics defined in the GATT database, and sometimes the length of the characteristic exceeds the MTU negotiated by the client and server Bluetooth LE devices. For this scenario, the Bluetooth LE specification defines a procedure to write and read the characteristic of interest. In summary, it consists in perform multiple writes and reads on the same characteristic value, using specific commands. For the "write long characteristic value" procedure, these commands are ATT_PREPARE_WRITE_REQ and ATT_EXECUTE_WRITE_REQ. For the "read long characteristic value" procedure, these commands are ATT_READ_REQ and ATT_READ_BLOB_REQ. This document provides an example of how to write and read long characteristic values, from the perspective of Client and Server devices.   APIs to Write and Read Characteristic Values Write Characteristic Values The GattClient_WriteCharacteristicValue API is used to perform any write operation. It is implemented by the GATT Client device. The following table describes the input parameters. Input Parameters Description deviceId_t deviceId Device ID of the peer device. gattCharacteristic_t * pCharacteristic Pointer to a gattCharacteristic struct type. This struct must contain a valid handle of the characteristic value in the "value.handle" field. The handle of the characteristic value that you want to write is commonly obtained after the service discovery procedure.  uint16_t valueLength This value indicates the length of the array pointed by aValue. const uint8_t * aValue Pointer to an array containing the value that will be written to the GATT database. bool_t withoutResponse If true, it means that the application wishes to perform a "Write Without Response", in other words, when the command will be ATT_WRITE_CMD or ATT_SIGNED_WRITE_CMD. bool_t signedWrite If withoutResponse and signedWrite are both true, the command will be ATT_SIGNED_WRITE_CMD. If withoutResponse is false, this parameter is ignored. bool_t doReliableLongCharWrites This field must be set to true if the application needs to write a long characteristic value. const uint8_t * aCsrk If withoutResponse and signedWrite are both true, this pointer must contain the CSRK to sign the data. Otherwise, this parameter is ignored.   Read Characteristic Values The GattClient_ReadCharacteristicValue API is used to perform read operations. It is implemented by the GATT Client device. The following table describes the input parameters. Input Parameters Description deviceId_t deviceId Device ID of the peer device. gattCharacteristic_t * pIoCharacteristic Pointer to a gattCharacteristic struct type. This struct must contain a valid handle of the characteristic value in the "value.handle" field. The handle of the characteristic value that you want to write is commonly obtained after the service discovery procedure. As well, the "value.paValue" field of this struct, must point to an array which will contain the characteristic value read from the peer. unit16_t maxReadBytes The length of the characteristic value that should be read. This API takes care of the long characteristics, so there is no need to worry about a special parameter or configuration. The following sections provide a functional example of how to write and read long characteristics. This example was based on the temperature collector and temperature sensor SDK examples. The example also shows how to create a custom service at the GATT database and how to discover its characteristics.   Bluetooth LE Server (Temperature Sensor) Modifications in gatt_uuid128.h Define the 128 bit UUID of the "custom service" which will be used for this example. Add the following code: /* Custom service */ UUID128(uuid_service_custom, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x00, 0x01, 0xFF, 0x01) UUID128(uuid_char_custom, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x01, 0x01, 0xFF, 0x01)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Modifications in gatt_db.h Define the characteristics of the "custom service", for this example, our service will have just one characteristic, it can be written or read, and it has a variable-length limited to 400 bytes (remember that the ATT_MTU of KW36 is 247 byte, so with this length, we ensure long writes and reads). Add the following code: PRIMARY_SERVICE_UUID128(service_custom, uuid_service_custom) CHARACTERISTIC_UUID128(char_custom, uuid_char_custom, (gGattCharPropWrite_c | gGattCharPropRead_c)) VALUE_UUID128_VARLEN(value_custom, uuid_char_custom, (gPermissionFlagWritable_c | gPermissionFlagReadable_c), 400, 1)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Modifications in app_preinclude.h One of the most important considerations to write and read long characteristics is the memory allocation needed for this. You must increment the current "AppPoolsDetails_c" configuration, the "_block_size_" and "_number_of_blocks_". Please ensure that "_block_size_" is aligned with 4 bytes. Once you have found the configuration that works in your application, please follow the steps in Memory Pool Optimizer on MKW3xA/KW3xZ Application Note, to found the best configuration without waste memory resources. For this example, configure "AppPoolsDetails_c" as follows: /* Defines pools by block size and number of blocks. Must be aligned to 4 bytes.*/ #define AppPoolsDetails_c \ _block_size_ 264 _number_of_blocks_ 8 _eol_‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Bluetooth LE Client (Temperature Collector) Modifications in gatt_uuid128.h Define the 128 bit UUID of the "custom service" which will be used for this example. Add the following code: /* Custom service */ UUID128(uuid_service_custom, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x00, 0x01, 0xFF, 0x01) UUID128(uuid_char_custom, 0xE0, 0x1C, 0x4B, 0x5E, 0x1E, 0xEB, 0xA1, 0x5C, 0xEE, 0xF4, 0x5E, 0xBA, 0x01, 0x01, 0xFF, 0x01)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Modifications in temperature_collector.c 1. Define the following variables at the "Private type definitions" section: typedef struct customServiceConfig_tag { uint16_t hService; uint16_t hCharacteristic; } customServiceConfig_t; typedef struct appCustomInfo_tag { tmcConfig_t tempClientConfig; customServiceConfig_t customServiceClientConfig; }appCustomInfo_t; typedef enum { mCustomServiceWrite = 0, mCustomServiceRead }customServiceState_t;‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ 2. Add two arrays of 400 bytes, one to send and the other to receive the data from the server in "Private memory declarations" section: /* Dummy array for custom service */ uint8_t mWriteDummyArray[400]; uint8_t mReadDummyArray[400];‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ 3. Define a new function in "Private functions prototypes" section, to write and read the characteristic value: static void BleApp_SendReceiveCustomService (customServiceState_t state);‍‍‍‍ 4. Locate the "BleApp_Config" function, add the following code here to fill the "mWriteDummyArray" with a known pattern before to write our custom characteristic. static void BleApp_Config(void) { uint16_t fill_pattern; /* Fill pattern to write long characteristic */ for (fill_pattern = 0; fill_pattern<400; fill_pattern++) { mWriteDummyArray[fill_pattern] = (uint8_t)fill_pattern; } /* Configure as GAP Central */ BleConnManager_GapCommonConfig(); ... ... }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ 5. Locate the "BleApp_StoreServiceHandles" function. Modify this function to include our custom service in the service discovery procedure. This is to save the handle of the custom characteristic since it is used by GattClient_WriteCharacteristicValue and GattClient_ReadCharacteristicValue APIs. static void BleApp_StoreServiceHandles ( gattService_t *pService ) { uint8_t i,j; if ((pService->uuidType == gBleUuidType128_c) && FLib_MemCmp(pService->uuid.uuid128, uuid_service_temperature, 16)) { /* Found Temperature Service */ mPeerInformation.customInfo.tempClientConfig.hService = pService->startHandle; for (i = 0; i < pService->cNumCharacteristics; i++) { if ((pService->aCharacteristics[i].value.uuidType == gBleUuidType16_c) && (pService->aCharacteristics[i].value.uuid.uuid16 == gBleSig_Temperature_d)) { /* Found Temperature Char */ mPeerInformation.customInfo.tempClientConfig.hTemperature = pService->aCharacteristics[i].value.handle; for (j = 0; j < pService->aCharacteristics[i].cNumDescriptors; j++) { if (pService->aCharacteristics[i].aDescriptors[j].uuidType == gBleUuidType16_c) { switch (pService->aCharacteristics[i].aDescriptors[j].uuid.uuid16) { /* Found Temperature Char Presentation Format Descriptor */ case gBleSig_CharPresFormatDescriptor_d: { mPeerInformation.customInfo.tempClientConfig.hTempDesc = pService->aCharacteristics[i].aDescriptors[j].handle; break; } /* Found Temperature Char CCCD */ case gBleSig_CCCD_d: { mPeerInformation.customInfo.tempClientConfig.hTempCccd = pService->aCharacteristics[i].aDescriptors[j].handle; break; } default: ; /* No action required */ break; } } } } } } else if ((pService->uuidType == gBleUuidType128_c) && FLib_MemCmp(pService->uuid.uuid128, uuid_service_custom, 16)) { /* Found Custom Service */ mPeerInformation.customInfo.customServiceClientConfig.hService = pService->startHandle; if (pService->cNumCharacteristics > 0U && pService->aCharacteristics != NULL) { /* Found Custom Characteristic */ mPeerInformation.customInfo.customServiceClientConfig.hCharacteristic = pService->aCharacteristics[0].value.handle; } } else { ; } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ 6. Develop the "BleApp_SendReceiveCustomService" as shown below. This function is used to write and read the custom characteristic values using long operations. Focus your attention in this function, here is the example of how to use GattClient_WriteCharacteristicValue and GattClient_ReadCharacteristicValue APIs to write and read long characteristic values. Note that the "characteristic" struct was filled before to use the last APIs, with the handle of our custom characteristic and a destination address to receive the value read from the peer. Note that the "doReliableLongCharWrites" field must be TRUE to allow long writes using GattClient_WriteCharacteristicValue.  static void BleApp_SendReceiveCustomService (customServiceState_t state) { bleResult_t bleResult; gattCharacteristic_t characteristic; /* Verify if there is a valid peer */ if (gInvalidDeviceId_c != mPeerInformation.deviceId) { /* Fill the characteristic struct with a read destiny and the custom service handle */ characteristic.value.handle = mPeerInformation.customInfo.customServiceClientConfig.hCharacteristic; characteristic.value.paValue = &mReadDummyArray[0]; /* Try to write the custom characteristic value */ if(mCustomServiceWrite == state) { bleResult = GattClient_WriteCharacteristicValue(mPeerInformation.deviceId, &characteristic, (uint16_t)400, &mWriteDummyArray[0], FALSE, FALSE, TRUE, NULL); /* An error occurred while trying to write the custom characteristic value, disconnect */ if(gBleSuccess_c != bleResult) { (void)Gap_Disconnect(mPeerInformation.deviceId); } } /* Try to read the custom characteristic value */ else { bleResult = GattClient_ReadCharacteristicValue(mPeerInformation.deviceId, &characteristic, (uint16_t)400); /* An error occurred while trying to read the custom characteristic value, disconnect */ if(gBleSuccess_c != bleResult) { (void)Gap_Disconnect(mPeerInformation.deviceId); } } } }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ 7. Modify the "BleApp_GattClientCallback" as shown below. In this function, we implement the "BleApp_SendReceiveCustomService" which writes or reads the characteristic depending on the input parameter "state". The expected behavior of this example is, first, write the 400-byte pattern contained in the mWriteDummyArray to our custom characteristic value, just after to write the characteristic descriptor of the temperature service (which is indicated by this callback in the gGattProcWriteCharacteristicDescriptor_c event). When the write has been executed successfully, it is indicated in this callback, by the "gGattProcWriteCharacteristicValue_c" event, therefore, here we can execute our function to read the characteristic value. Then "gGattProcReadCharacteristicValue_c" event is triggered if the read has been completed, here, we compare the value written with the value read from the GATT server and, if both are the same, the green RGB led should turn on indicating that our long characteristic has been written and read successfully, otherwise, the GATT client disconnects from the GATT server.   static void BleApp_GattClientCallback( deviceId_t serverDeviceId, gattProcedureType_t procedureType, gattProcedureResult_t procedureResult, bleResult_t error ) { if (procedureResult == gGattProcError_c) { attErrorCode_t attError = (attErrorCode_t)(uint8_t)(error); if (attError == gAttErrCodeInsufficientEncryption_c || attError == gAttErrCodeInsufficientAuthorization_c || attError == gAttErrCodeInsufficientAuthentication_c) { /* Start Pairing Procedure */ (void)Gap_Pair(serverDeviceId, &gPairingParameters); } BleApp_StateMachineHandler(serverDeviceId, mAppEvt_GattProcError_c); } else { if (procedureResult == gGattProcSuccess_c) { switch(procedureType) { case gGattProcReadCharacteristicDescriptor_c: { if (mpCharProcBuffer != NULL) { /* Store the value of the descriptor */ BleApp_StoreDescValues(mpCharProcBuffer); } break; } case gGattProcWriteCharacteristicDescriptor_c: { /* Try to write to the custom service */ BleApp_SendReceiveCustomService(mCustomServiceWrite); } break; case gGattProcWriteCharacteristicValue_c: { /* If write to the custom service was completed, try to read the custom service */ BleApp_SendReceiveCustomService(mCustomServiceRead); } break; case gGattProcReadCharacteristicValue_c: { /* If read to the custom service was completed, compare write and read buffers */ if(FLib_MemCmp(&mWriteDummyArray[0], &mReadDummyArray[0], 400)) { Led3On(); } else { (void)Gap_Disconnect(mPeerInformation.deviceId); } } break; default: { ; /* No action required */ break; } } BleApp_StateMachineHandler(serverDeviceId, mAppEvt_GattProcComplete_c); } } /* Signal Service Discovery Module */ BleServDisc_SignalGattClientEvent(serverDeviceId, procedureType, procedureResult, error); }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ Modifications in app_preinclude.h One of the most important considerations to write and read long characteristics is the memory allocation needed for this. You must increment the current "AppPoolsDetails_c" configuration, the "_block_size_" and "_number_of_blocks_". Please ensure that "_block_size_" is aligned with 4 bytes. You can know when the current configuration of pools do not satisfy the application requirements if the return value of either "GattClient_WriteCharacteristicValue" or "GattClient_ReadCharacteristicValue " is "gBleOutOfMemory_c" instead of "gBleSuccess_c" (If it is the case, the device will disconnect to the peer according to the code in step 6 in "Modifications in temperature_collector.c"). Once you have found the configuration that works in your application, please follow the steps in Memory Pool Optimizer on MKW3xA/KW3xZ Application Note, to found the best configuration without waste memory resources. For this example, configure "AppPoolsDetails_c" as follows: /* Defines pools by block size and number of blocks. Must be aligned to 4 bytes.*/ #define AppPoolsDetails_c \ _block_size_ 112 _number_of_blocks_ 6 _eol_ \ _block_size_ 256 _number_of_blocks_ 3 _eol_ \ _block_size_ 280 _number_of_blocks_ 2 _eol_ \ _block_size_ 432 _number_of_blocks_ 1 _eol_‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Please let us know any question regarding this topic.