W2023 Firmware Architecture

Goal: Figure out a way to send commands from the Jetson to Cytron/other PWM motor controllers, via an intermediary system or other method, and read information back from those motor controllers (e.g: encoders on the motors).

Requirements:

• Needs to be able to powered by the battery/another rail

• Should be fast < 200ms response

• Controllable via Jetson pinout

• Needs to send commands over PWM

• Should be able to read from it as well; not only write (in case of encoders)

Architecture decisions:

• Decide on second board/module to use to use (e.g: nucleo or Adafruit 16-Channel I2C servo driver)

  • Nucleo:

    • Customizable

    • Hard real-time

    • Already have multiple boards in the bay

    • Familiar to firmware team

    • Extensible

    • Slowest to get working (freeRTOS, multiple threads, etc.)

  • Adafruit:

    • Has up to 12 PWM outputs

    • Has no customizable MCU; cannot write custom code, cannot read from encoders

    • Fastest to get working

  • Arduino:

    • Easy (libraries)

    • Fast to set up

• Decide on which RTOS to use (freeRTOS cool w yall?)

  • HAL

• Decide on which protocol to use to communicate from Jetson to nucleo if using nucleo; CAN or I2C?

Tasks to Allocate:

• Create a new repository for firmware

• Use STM32CubeIDE to set up the project with both freeRTOS and the STM32HAL; upload to the repository

• Create ~4 threads running from functions in separate files such that work can continue concurrently

• Create PWM code for basic control of current science mechansim motors

• Create PWM code for basic control of gimbal servo + gimbal slip ring motor

• ODrive wiring for arm

• Create code for reading and writing data over /CAN; assume the data coming from the Jetson over I2C/CAN is a struct such as the following:
  -> Gimbal servo desired location (0 to 360 deg)
  -> Gimbal slip ring desired location (0 to 360 deg)
  -> Science mechanism fan speed
  -> Science mechanism drill speed
  -> Science mechanism pulley speed
  etc...