FEZ T18 Rev D as native STM32F401 target (FreeRTOS / RTX)

Off Topic
1

I have two FEZ T18 Rev D boards, one with WiFi and one without. I know these boards are discontinued, but I hate to see things go to waste.

My goal is to completely remove the GHI software stack and use the board as a native STM32F401 development target with either:

  • STM32CubeIDE + FreeRTOS
  • Keil MDK + RTX5

I’ve already identified:

  • PA13 = SWDIO
  • PA14 = SWCLK
  • BOOT0 button present
  • NRST available
  • STM32F401xD/xE MCU

Before I connect an ST-LINK and erase the device, I’d like to verify a few board-specific details:

  1. Is there any protection mechanism, option-byte configuration, or flash-region reservation on the FEZ T18 that would interfere with a complete chip erase and replacement with native STM32 firmware?

  2. Has anyone successfully used ST-LINK/V2 or ST-LINK/V3 to completely erase and reprogram a FEZ T18 as a generic STM32F401 target?

  3. Does GHI have any board-support package, startup code, linker script, CMSIS package, CubeMX project, Keil project, or FreeRTOS/RTX example project that was used when the board documentation stated support for Keil OS and FreeRTOS?

  4. Is the actual MCU part number on all T18 Rev D boards the same, or were both STM32F401xD and STM32F401xE devices shipped?

  5. After a mass erase, are there any board-specific peripherals that require special initialization beyond what is shown in the schematic (USB interface, WiFi module, power control, etc.)?

  6. Are there any known issues using the exposed SWD header as the primary programming/debugging interface?

My intention is to treat the board as a standard STM32F401 target and perform all development with native ARM tools, rather than NETMF or TinyCLR.

Thanks for your time and consideration.

2

We do not traditionally have support for what you are trying to do. That said, you might be able to do full erase in the chip and then you just have an ST chip.

The protection level might prevent you from doing an eraser all but it is easy give it a try. Good luck

3

The reason I even thought this might be possible was this statement on the page for the FEZT18 from your web site in 2018: “FEZ works with several third party tools, like Arduino®, mbed®, MicroPython, Keil, GCC, FreeRTOS. The very popular STM32F401 microcontroller utilized on FEZ opens the door to almost every single maker and commercial platform.”

4

Aha then this was an open source board. I can’t remember. You should have no problem using it then.