stm32-service-node

How it works

• This is firmware for STM32F4 to communicate with the new microservices of CFSD over USB serial. The service code can be found at https://github.com/chalmersfsd/opendlv-device-stm32-lynx/tree/development
• STM32 receives GPIO/PWM requests from Docker side, and execute these requests.
• It it request-response communication where Docker side should send requests and STM would respond to them.

Dependencies

• ChibiOS 18.2. This is included in the repository.
• STM32F4 running a serial-over-usb connection (micro-usb), drivers for the board installed.
• Dockerized microservice running OpenDLV. This service can be found at https://github.com/chalmersfsd/opendlv-device-stm32-lynx/tree/development.
• Pin configuration is described in "stm32_pin_map.xlsx", and is configured at src/chibios182/os/hal/boards/ST_STM32F4_DISCOVERY/board.h. Change this file if you want another pin config.

Getting it working

Utilizing Makefile in root directory. Help output is available, free to run make and read it.

• Build all tools, firmware and flash: make all
• Create docker images for building and flashing firmware: make builder && make flasher
• Build firmware (given you have corresponding docker image): make build
• Flash firmware make flash

Function description

The code has 3 threads, whose purposes and related functions are described below:

• usbThread: blink the orange LED according to the Serial over USB status; slow blink (1Hz) means no connection, and fast blink (2Hz) means good connection.

• readThread: collects & decode the Netstring bytes sent from Docker side. The bytes are first received using sdReadTimeout & stored in chunkBuffer (a temporary buffer), then receiveBuffer (this is the main storing buffer, where most read actions are performed on). A char* pointer, writePtr, is used to keep track of where in receiveBuffer the reading is taking place. This is done by the following functions:

  • consumeNetstring(): a temporary function to remember the position of writePtr.
  • decodeNextNetstring(): the main reading function. It parses the bytes in receiveBuffer, looking for a valid Netstring by looking for the number of bytes (payload length of Netstring) using strtol. Once that number is found, it checks for the end delimeter of the Netstring (';'); if that is also found, then it means it found a valid Netstring, and will extract & decode the payload in decodeRequest(). The extracted payload is stored in messageBuffer. After that, the read Netstring are removed from receiveBuffer by memmove, and by moving the writePtr.
  • decodeRequest(): decodes the payload based on a pre-defined mesage format. The format is: "set|pinID|value". E.g: "set|compressor|1", "set|ebs_line|0", "set|steer_speed|50000",...

• writeThread: sends measurements to Docker side. The procedure is the opposite of reading: the measurements are first encoded according to the pre-defined format,e.g: "status|ebs_line|1234", "status|ebs_actuator|1234", then encoded as Netstring, and finally sent over USB using sdWriteTimeout().

• adcSampleThread: samples the raw Analog measurements.

Related board config

Control

• PB0 - PWM_LINEAR_ACTUATOR (alternate 2).
• PB1 - PWM_PRESSURE (alternate 2).
• PB5 - PWM_ASSI_RED (alternate 2).
• PB6 - PWM_ASSI_GREEN (alternate 2).
• PB7 - PWM_ASSI_BLUE (alternate 2).
• PB8 - CAN1_RX (alternate 9).
• PB9 - CAN1_TX (alternate 9).
• PB12 - CAN2_RX (alternate 9).
• PB13 - CAN2_TX (alternate 9).
• PD0 - PD_HEART_BEAT (output pushpull maximum).
• PD1 - PD_RACK_RIGHT (output pushpull maximum).
• PD2 - PD_RACK_LEFT (output pushpull maximum).
• PD3 - PD_SERVICE_BREAK (output pushpull maximum).
• PD4 - PD_REDUNDENCY (output pushpull maximum).
• PD6 - PD_SHUTDOWN (output pushpull maximum).
• PD7 - PD_SPARE (output pushpull maximum).
• PD8 - PD_CLAMP_SET (output pushpull maximum).
• PD9 - PD_COMPRESSOR (output pushpull maximum).
• PD10 - PD_EBS_RELIEF (output pushpull maximum).
• PD11 - PD_EBS_SPEAKER (output pushpull maximum).
• PD12 - PD_FINISHED (output pushpull maximum).
• PD13 - LED3 (output pushpull maximum).
• PD14 - LED5 (output pushpull maximum).
• PD15 - LED6 (output pushpull maximum).

Sensor reads

• PC0 - EBS_LINE_READ (analog).
• PC1 - EBS_ACTUATOR_READ (analog).
• PC2 - PRESSURE_RAD_READ (analog).
• PC3 - SERVICE_TANK_READ (analog).
• PC4 - POSITION_RACK_READ (analog).
• PC5 - STEARING_POS_READ (analog).
• PC13 - ASMS_READ (input pullup).
• PC14 - CLAMPED_SENS_READ (input pullup).
• PC15 - EBS_OK_READ (input pullup).

To-do

• Re-calibrate sensor measurements.
• Continue debugging to find possible bugs