topquark12 / cybathlonsensornode

firmware for HKUST Cybathlon sensor node (IMU and magnetic encoder)

IMU and magnetic encoder sensor node

This repositry stores PCB files and firmware for HKUST Cybathlon sensor node.
Repositry created and maintained by Alex Wong.

Hardware

Function

Each sensor node is intended to contain either a ICM-20602 IMU or MA730 magnetic rotary encoder. It is also possible for one node to contain both sensors.
The sensor nodes are designed to be mounted on various points on the exoskeleton to sense limb attitude or joint angle.

Communication

Sensor nodes communicate through a 1Mbaud CAN bus network, each node broadcasts sensor readings to the network.
All sensor nodes should be daisy-chained with JST GH 8-pin cables for power and data.
Termination connectors must be connected to both ends of the daisy chain to ensure signal integrity.
Data from all the sensors can be read out at any one of the sensor nodes, through the on-board USB-C port and USB to serial converter.
It is also possible for sensor nodes to log sensor or CAN bus data to the on-board SD-card slot.

Power

Sensor nodes can either be powered through the two JST GH 8-pin connectors or through the USB type-C connector.
Nominal voltage input range: 4.5v to 6v.
All sensor nodes are protected from over voltage and reversed voltage, surviving from -64v to 64v (limited by testing method).
Each sensor node is rated at 200mA in normal operation, and will draw at most 350mA at short circuit.

Software

Dependencies

Build tool: GNU Make
Tool Chain: arm-gcc-none-eabi
HAL: STM32Cube (files included in repositry)
Middlewares: freeRTOS, fatfs (files included in repositry)

Flashing and debugging

There are multiple options for flashing firmware and optionally debug the board.

1. On-board 1.27mm 2x5-pin SWD debug port (with SWO)
   ARM debug probes (e.g. STLink, J-link, uLink etc.) can be connected to this port fo program and debug the on-board MCU. Segger J-Link and Segger Ozone is recommended.

2. On-board USB type-C port and USB to serial converter
   The USB to serial chip is connected to the USART1 port of the STM32F405RG MCU, allowing the MCU to be programmed through the USB port without additional hardware. To use this feature, set the on-board BOOT0 switch to 1, before pressing the reset button. Use software tools like the FLASHER-STM32 to flash binaries into the MCU. After flashing, set the on-board BOOT0 switch to 0, then reset the MCU and the new code will run. This method does not provide debugging capabilities.