This demo application connects to Google Cloud IoT through MQTT and publishes messages.
It requires a registered device.
The following describes the various components and the configuration settings.
Once the application is configured you can:
- Build the application.
- Connect the debugger.
- Run the application and view messages in a debug printf or terminal window.
The file demo.c configures the connection to Google IoT with these settings:
PROJECT_ID: Project IDCLOUD_REGION: Cloud regionREGISTRY_ID: Registry IDDEVICE_ID: Device ID
Note: These settings need to be configured by the user!
The file pkey.h configures the device private key.
Note: The device private key needs to be provided by the user!
The real-time operating system FreeRTOS implements the resource management.
It is configured with the following settings:
- Minimal stack size [words]: 768
- Total heap size [bytes]: 24000
- Preemption interrupt priority: 128
- Event Recorder configuration
- Initialize Event Recorder: 1
Refer to Configure CMSIS-FreeRTOS for a detailed description of all configuration options.
This implementation uses an IoT socket layer that connects to a CMSIS-Driver WiFi.
The file socket_startup.c configures the WiFi connection with these settings:
- SSID: network identifier
- PASSWORD: network password
- SECURITY_TYPE: network security
Note: These settings need to be configured by the user!
The WiFi shield based on ESP8266 SoC is connected via an Arduino header using a USART interface. It exposes a CMSIS-Driver WiFi.
This module was tested with the ESP8266 AT command set firmware revision 1.6.2. Refer to Espressif Product Support Download for more information.
The tables below list the device configuration for this board. The board layer for the NXP FRDM-K32L3A6 is using the software component ::Board Support: SDK Project Template: project_template (Variant: frdmk32l3a6) from NXP.FRDM-K32L3A6_BSP.13.0.0 pack.
The heap/stack setup and the CMSIS-Driver assignment is in configuration files of related software components.
The example project can be re-configured to work on custom hardware. Refer to "Configuring Example Projects with MCUXpresso Config Tools" for information.
| System Component | Setting |
|---|---|
| Device | K32L3A60VPJ1A:cm4 |
| Board | FRDM-K32L3A6 |
| SDK Version | ksdk2_0 |
| Heap | 64 kB (configured in linker script K32L3A60xxx_cm4*.scf file) |
| Stack (MSP) | 1 kB (configured in linker script K32L3A60xxx_cm4*.scf file) |
| Clock | Setting |
|---|---|
| FIRC | 48 MHz |
| FIRC DIV1 clock | 48 MHz |
| FIRC DIV2 clock | 48 MHz |
| FIRC DIV3 clock | 48 MHz |
| LPUART0 clock | 48 MHz |
| LPUART1 clock | 48 MHz |
| LPSPI0 clock | 48 MHz |
| LPI2C3 clock | 48 MHz |
Note: configured with Functional Group: BOARD_BootClockRUN
| Functional Group | Pin | Peripheral | Signal | Identifier | Pin Settings | Usage |
|---|---|---|---|---|---|---|
| BOARD_InitDEBUG_UART | N2 | LPUART0 | TX | DEBUG_UART0_TX | default | LPUART0 TX for debug console (PTC8) |
| BOARD_InitDEBUG_UART | P3 | LPUART0 | RX | DEBUG_UART0_RX | default | LPUART0 RX for debug console (PTC7) |
| BOARD_InitLEDs | D6 | GPIOA | GPIO, 24 | RGB_RED | default | User LED1 (PTA24) |
| BOARD_InitLEDs | E6 | GPIOA | GPIO, 23 | RGB_GREEN | default | User LED2 (PTA23) |
| BOARD_InitLEDs | B6 | GPIOA | GPIO, 22 | RGB_BLUE | default | User LED3 (PTA22) |
| BOARD_InitButtons | B10 | GPIOA | GPIO, 0 | SW2 | default | User Button SW2 (PTA2) |
| BOARD_InitButtons | P16 | GPIOE | GPIO, 8 | SW3 | default | User Button SW3 (PTE8) |
| BOARD_InitButtons | N16 | GPIOE | GPIO, 9 | SW4 | default | User Button SW4 (PTE9) |
| BOARD_InitButtons | L12 | GPIOE | GPIO, 12 | SW5 | default | User Button SW5 (PTE12) |
| BOARD_InitARDUINO_UART | A5 | LPUART1 | TX | ARDUINO_LPUART1_TX | default | Arduino UNO R3 pin D1 (PTA26) |
| BOARD_InitARDUINO_UART | B5 | LPUART1 | RX | ARDUINO_LPUART1_RX | default | Arduino UNO R3 pin D0 (PTA27) |
| BOARD_InitARDUINO_SPI | C2 | LPSPI0 | SCK | ARDUINO_SPI_SCK | default | Arduino UNO R3 pin D13 (PTB4) |
| BOARD_InitARDUINO_SPI | D2 | LPSPI0 | SOUT | ARDUINO_SPI_MOSI | default | Arduino UNO R3 pin D11 (PTB5) |
| BOARD_InitARDUINO_SPI | E2 | LPSPI0 | SIN | ARDUINO_SPI_MISO | default | Arduino UNO R3 pin D12 (PTB7) |
| BOARD_InitARDUINO_SPI | E1 | GPIOB | GPIO, 6 | ARDUINO_SPI_SSN | Direction Output, GPIO initial state 1 | Arduino UNO R3 pin D10 (PTB6) |
| BOARD_InitPins_Arduino_PTB3 | C1 | GPIOB | GPIO, 3 | ARDUINO_PTB3 | Direction Input | Arduino UNO R3 pin D9 (PTB3) |
| NVIC Interrupt | Priority |
|---|---|
| LPUART1 | 4 |
| LPSPI0 | 4 |
STDIO is routed to debug console through Virtual COM port (DAP-Link, peripheral = LPUART0, baudrate = 115200)
| CMSIS-Driver | Peripheral |
|---|---|
| USART1 | LPUART1 |
| SPI0 | LPSPI0 |
| CMSIS-Driver VIO | Physical board hardware |
|---|---|
| vioBUTTON0 | User Button SW2 |
| vioBUTTON1 | User Button SW3 |
| vioBUTTON2 | User Button SW4 |
| vioBUTTON3 | User Button SW5 |
| vioLED0 | User LED RED |
| vioLED1 | User LED GREEN |
| vioLED2 | User LED BLUE |
| vioMotionAccelero | MEMS accelerometer(FXOS8700CQ) |
| vioMotionMagneto | MEMS magnetometer (FXOS8700CQ) |