MTB-USB v4 Firmware

This repository contains firmware for main MCU STM32F103 of MTB-USB v4 module. MTB-USB module is a master module of MTBbus.

Module functionality

• Retransmit data between MTBbus and USB (PC).
• Do MTBbus (RS485) time-critical operations.
• Periodically poll MTBbus modules to let them report events.
• Maintain list of active & inactive modules. Poll active modules frequently, poll rest of the modules less frequently to allow to find new modules.
• Check if module responds to inquiry. When no response is get multiple times, report module as failed
• Behaves as CDC in PC.

LEDs behavior

• Red led: bad checksum of mtbbus received.
• Yellow led: USB send traffic.
  • Permanently on: computer does not read from USB CDC.
  • Permanently off: computer reads CDC, no data are sent.
  • Flashing: computer reads CDC, data are sent to computer.
• Green led: MTBbus activity: polling MTBbus modules.
• Blue led left: no meaning yet.
• Blue led right: MTBbus powered.

Build & requirements

• Development:

  • arm-none-eabi-gcc
  • bootloader: build it and symlink bootloader.bin to built binary.
  • make

    $ make

• Debugging:

  • openocd
  • arm-none-eabi-gdb

    $ openocd
    $ arm-none-eabi-gdb build/mtb-usb-4.elf
    (gdb) target extended-remote :3333
    (gdb) b main

• Flashing: There are two independent options for firmware flashing to MTB-USB.

  1. st-flash (via STlink) MTB-USB module contains programming connector. Use STlink to program the MCU.

     $ make flash_with_bootloader

  2. Via DFU bootloader in MTB-USB (if bootloader already present in MTB-USB).

     $ ./reboot_to_dfu.sh
     $ make flash_dfu

References

• MTB-USB v4 PCB
• MTBbus protocol
• PC – MTB-USB module protocol
• MTB project (in czech only)

License

This application is released under the Apache License v2.0 .