Modification of BLE Temperature service KW45

[sshrivastava]

Hi, 

We modified the BLE temperature service to send and receive more data (48 Bytes). Below are the changes that are done.

Server:

1. gatt_db.h

PRIMARY_SERVICE_UUID128(service_temperature, uuid_service_temperature)
    CHARACTERISTIC(char_temperature, gBleSig_Temperature_d, (gGattCharPropWriteWithoutRsp_c))
        VALUE(value_temperature, gBleSig_Temperature_d, (gPermissionFlagReadable_c | gPermissionFlagWritable_c), 48, 0x00, 0xB4)
        DESCRIPTOR(desc_temperature, gBleSig_CharPresFormatDescriptor_d, (gPermissionFlagReadable_c | gPermissionFlagWritable_c), 7, 0x0E, 0xFE, 0x2F, 0x27, 0x00, 0x00, 0x00)

2. ble_constants.h

/*! Default value of the ATT_MTU */
#define gAttDefaultMtu_c                (48U)

Client:

1. ble_constants.h

/*! Default value of the ATT_MTU */
#define gAttDefaultMtu_c                (48U)

Everything goes well during pairing, we can send and receive on both sides 48 bytes.

After disconnecting and connecting the BLE, We receive only 20 bytes of data.

Are we missing any configuration settings? 

#KW45 KW45B41Z-EVK 

[Itzel_UV]

Hello,

I will be helping you with your question.

For more information on GATT database definitions, please consult the Chapter 7.1.3.2 from the SDK_KW45B41Z-EVK\docs\wireless\BluetoothSDKKW45\Bluetooth Low Energy Application Developer’s Guide to see what's supposed to be done to declare the Characteristic Value.

For other reference check the Costum profile, keep on mind that this example is done on the QN9090, but the process is more or less the same.

On the other hand, for more information on ATT_MTU, you could look for more details on the MTU Exchange on the chapter 5.1.2 from the previous guide. Some Server considerations can also be found in chapter 5.2.

Regards.

Itzel Uribe