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By default the clock configuration on the KW2xD demos is set to PLL Engaged External (PEE). In this mode the system clock is derived from the output of the PLL and controlled by an external reference clock. The modem provides a programmable clock source output CLK_OUT that can be used as the external reference clock for the PLL. In the Figure 1 we can see that the CLK_OUT modem signal is internally connected to EXTAL0 in the MCU.   The CLK_OUT output frequency is controlled by programming the modem 3-bit field CLK_OUT_DIV [2:0] in the CLK_OUT_CTRL Register. The default frequency is either 32.787 kHz or 4 MHz depending on the state of the modem GPIO5 at reset determined by the MCU. See section 4.4.2 and 5.6.2 from the MKW2xD Reference Manual for more information on the clock output feature. If the GPIO5 modem pin is low upon POR, then the frequency will be 4 MHz. If this GPIO5 modem pin is high upon POR, then the frequency will be 32.78689 kHz.   In the KW2xD demos, the GPIO5 (PTC0) is held low during the modem reset so the CLK_OUT has a frequency of 4MHz. The clock configuration structure g_defaultClockConfigRun is defined in board.c. Figure 1. Internal Functional Interconnects   In this example project, another clock configuration will be added to the Connectivity Test Project: FLL Engaged Internal (FEI). In this mode, the system clock is derived from the FLL clock that is controlled by the 32kHz Internal reference clock.   In FEI mode the MCU doesn’t need the clock source output CLK_OUT from the modem, so we can disable the radio’s clock output and then set the radio to Hibernate to save power when we are not using the radio.   If the low-power module from the connectivity framework is used to go to a low-power mode, the clock configuration is changed automatically when entering a sleep mode (See the Connectivity Framework Reference Manual for more information about the low-power library).   System Requirements Kinetis MKW2xD and MCR20A Connectivity Software (REV 1.0.0) TWR-KW24D512 IAR Embedded Workbench for ARM 7.60.1 or later Attached project files Application Description The clock configuration can be changed with shortcuts on the serial console: Press “c” to use the PEE clock configuration (default). Press “v” to use the FEI clock configuration and set the radio to Autodoze. Press “b” to use the FEI clock configuration and set the radio to Hibernate.   You must be in the main menu in order to change the radio mode, the mode automatically changes to Autodoze when entering a test menu.   Hibernate mode can only be changed when in FEI mode. This is because in hibernate the radio disables the CLK_OUT and the PEE configuration needs this clock.   Current Measurements The following measurements were done in a TWR-KW24D256 through J2 5-6 to measure the radio current. Table 1. Radio Current Measurements Clock mode/Radio mode Radio Current PEE/Autodoze 615µA FEI/Autodoze 417µA FEI/Hibernate 0.3µA   Code Modifications The following modifications to the source files were made: \boards\twrkw24d512\Board.c Added clock user configuration Added array of clock configs and configuration struct for clock callback   \boards\twrkw24d512\Board.h Include for fsl_clock_manager.h Declaration of clock callback and configuration array used in CLOCK_SYS_Init() function.   \boards\twrkw24d512\Hardware_init.c Added calibration code after BOARD_ClockInit(), this is to calibrate internal clock using the bus clock.   \examples\smac\Connectivity_Test\common\Connectivity_TestApp.c Initialize the clock manager. Disable PTC0 because it is only used at modem reset to select the CLK_OUT default frequency (4MHz). Return clock configuration on idle state. Prepare radio to go to Autodoze when entering a test menu.   \examples\smac\Connectivity_Test\twrkw24d512\common\Connectivity_Test_Platform.c Changed length of the lines to be erased in PrintTestParameters() from 65 to 80 Added clock config and radio mode to be printed in the test parameters. Added the cases in the shortcut parser to change the clock and radio configuration with the keys “c”, “v” and “b”. Added functions at end of file (Explained in the next section).   \examples\smac\Connectivity_Test\twrkw24d512\common\Connectivity_Test_Platform.h Macros for the clock and radio modes. Function prototypes from the source file.   \examples\smac\Connectivity_Test\twrkw24d512\common\ConnectivityMenus.c Shortcuts descriptions.   The modified source files can be found attached to this document.   Functions added The functions PWRLib_Radio_Enter_Hibernate() and PWRLib_Radio_Enter_AutoDoze() were taken from the file PWRLib.c located at <Connectivity_Software_Path>\ConnSw\framework\LowPower\Source\KW2xD. The PWRLib.c file is part of the low-power library from the connectivity framework.   The Clock_Callback() function was implemented to handle when the clock configuration is updated. Inside the function there is a case to handle before and after the clock configuration is changed. Before the clock configuration is changed, the UART clock is disabled and if the clock configuration is PEE, the radio is set to AutoDoze and the CLK_OUT is enabled. After the clock configuration has changed, the Timer module is notified that the clock has changed, the UART is re-initialized and if the clock configuration is FEI, the CLK_OUT is disabled. This behavior is shown in Figure 2. Figure 2. Clock callback diagram   The prepareRadio() function is used when entering a test mode to make sure the radio is set to AutoDoze in case it was in hibernate. The restoreRadio() function is used when leaving the test menu and going to hibernate if it was previously set.
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Commissioner Authentication server for new Thread devices and the authorizer for providing the network credentials they require to join the network. A device capable of being elected as a Commissioner is called a Commissioner Candidate. Devices without Thread interfaces may perform this role, but those that have them may combine this role with all other roles except the Joiner. This device may be, for example, a cell phone or a server in the cloud, and typically provides the interface by which a human administrator manages joining a new device to the Thread Network. Commissioner Candidate A device that is capable of becoming the Commissioner, and either intends or is currently petitioning the Leader to become the Commissioner, but has not yet been formally assigned the role of Commissioner. Commissioner Credential A human-scaled passphrase for use in authenticating that a device may petition to become the commissioner of the network. This credential can be thought of as the network administrator password for a Thread Network. The first device in a network, typically the initial Leader, MUST be out-of-band commissioned to inject the correct user generated Commissioning Credential into the Thread Network, or provide a known default Commissioning Credential to be changed later. Joiner A device to be added by a human administrator to a commissioned Thread Network. This role requires a Thread interface to perform and cannot be combined with another role in one device. The Joiner does not have network credentials. Joiner Router An existing Thread router or REED (Router-Eligible End Device) on the secure Thread Network that is one radio hop away from the Joiner. The Joiner Router requires a Thread interface to operate, and may be combined in any device with other roles except the Joiner role. Information extracted from the Thread Whitepapers available at threadgroup.org
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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 a s 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
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The image below shows the different types of devices in a Thread Network. Router Routers provide routing services to network devices. Routers also provide joining and security services for devices trying to join the network. Routers are not designed to sleep. Routers can downgrade their functionality and become REEDs (Router-eligible End Devices). A Router can become a Leader and start a Thread network. Border Router A Border Router is a type of Router that provides connectivity from the 802.15.4 network to adjacent networks on other physical layers (for example, Wi-Fi and Ethernet). Border Routers provide services for devices within the 802.15.4 network, including routing services for off-network operations. There may be one or more Border Routers in a Thread Network. The Border Router also serves as an interface point for the Commissioner when the Commissioner is on a non-Thread Network; it requires a Thread interface and may be combined in any device with other Thread roles except the Joiner. Leader A Router or Border Router can assume a Leader role for certain functions in the Thread Network. This Leader is required to make decisions within the network. For example, the Leader assigns Router addresses and allows new Router requests. The Leader role is elected and if the Leader fails, another Router or Border Router assumes the Leader role. It is this autonomous operation that ensures there is no single point of failure. Router-eligible End Device REEDs have the capability to become Routers but due to the network topology or conditions these devices are not acting as Routers. These devices do not generally forward messages or provide joining or security services for other devices in the Thread Network. The Thread Network manages REEDs becoming Routers if necessary without user interaction. Sleepy End Device Sleepy end devices are host devices. They communicate only through their Parent Router and cannot forward messages for other devices References: Thread Whitepapers available at http://threadgroup.org 
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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.
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