STM32F4 example project
This example shows how to use mongoose on STM32 boards. To run it you will need:
- STM32F429-Discovery dev board
- CC3100 WiFi network processor
Wiring scheme
By default, example uses SPI4 for communication with CC3100 and UART1 for
the debug output. All parameters are described in file stm32f4xx_hal_msp.h,
they can be changed to use another SPI and/or UART
To use default scheme connect (CC3100 -> STM32-DISCO) connect:
DO -> PE5
DIN -> PE6
CLK -> PE2
CS -> PB12
IRQ -> PA0
HIB -> PB0
Building firmware
Change user_params.h, put correct WiFi SSID and password there,
also change MQTT_BROKER_ADDRESS to the real broker address.
make in mongoose/STM32F4_CC3100 will download required docker image and make
firmware. Result will be in STM32F4_CC3100/out folder.
Uploading firmare
Uploading firmware method depends on how you connected STM32 board to your
computer. If it is connected via USB ST-LINK connected it is appears as
a flash drive and in order to upload firmware just copy out/example.bin
to that drive.
Running
Compile two additional samples: mqtt_broker and mqtt_client and run them
in different terminals.
Press reset (or repower) STM board.
The board will connect to broker and will start to publish its uptime in
/stuff channel. mqtt_client is subscribed on this channel as well, so
it should start to print
Got incoming message /stuff: Current tick: 99000
Forwarding to /test
Got incoming message /stuff: Current tick: 100120
Forwarding to /test
Got incoming message /stuff: Current tick: 101250
Forwarding to /test
...
If you connect UART to serial port monitor (pin PA9 or ST-LINK device, like /dev/ttyACM0) you should see device output:
**** Hello ****
Initializing CC3100 on SPI4
Starting WiFi connect
Done, waiting for events
Connected to WiFi
Got IP
Connected to 192.168.1.108:1883
Connected to broker
Subscribing to /test
Subscription acknowledged
Publishing message with tick=1
Got incoming message /test: Current tick: 4487
Publishing message with tick=2
Got incoming message /test: Current tick: 5597
Publishing message with tick=3
Got incoming message /test: Current tick: 6717
...
This output looks like this because the device sends messages Current tick: ....
into /stuff channel, mqtt_client receives all messages in this channel
and sends them to /test channel. But the device is subscribed to this channel
so, it receives it back.