STM32 Serial To TCP Bridge Client

STM32 based client for SerialToTCPBridgeProtocol gateway service.

Open a TCP connection to a server from the STM32 using just UART. (No shields or network HW)
See this for more information on the protocol and for the Protocol Gateway you will need to run on the host the STM32 is connected to serially.
Currently, there is a MQTT protocol implementation over this connection as an example.

Used

• Atollic TrueSTUDIO for ARM Lite 5.5.2+
• STM32CubeMX plugin for Eclipse (4.15.1.201606091139)
• STM32F3 firmware package (1.5.0)
• STM32 Nucleo F334R8 board

How to

• Install software.
• Clone repo in your Atollic workspace.
• Open Atollic by clicking .project file.
• In Atollic, open the STM32CubeMX perspective.
• Inside STM32CubeMX, open STM32SerialToTCPBridgeClient.ioc file. Click Generate source code.
• In Atollic, open C/C++ perspective and click Rebuild.
• Get the Protocol Gateway and build it.
• Change the gateway's config to listen on the COM port connected to your STM32 and start it.
• With the STM32 Nucleo ST-Link debugger connected, click Debug to load the program.
• Once in the Debug perspective, click Resume to start program on STM32.

Details

• The protocol provides the app an in order, duplicates free and error checked byte stream by adding a CRC32 and simple retry mechanism. See this for background.
• The Protocol utilizes the internal CRC32 unit on the STM32 for communication error checking.
• The Protocol Gateway opens a real TCP connection to a set destination on behalf of the Protocol Client running on the STM32, and forwards traffic bi-directionally.

Included Example

• A stripped down version of knolleary's MQTT library for Arduino is used.
• When the microcontroller starts up it dials to a HiveMQ MQTT broker running on the host. (127.0.0.1, 1883)
• Pressing the button on the Nucleo board the first time causes it to subscribe to topic led/#. Subsequent presses publishes a message on another MQTT topic.
• Publishing 1 from another MQTT client to the led topic will power on the led on the Nucleo board. Publishing 2 will power it off.

Future plans

• Optimization & more protocol feature complete
• Unit tests