Please support the Nucleo C071RB

[DavidEGrayson]

I'd like to be able to program the Nucleo C071RB in PlatformIO.

The Nucleo C071RB is similar to the Nucleo G071RB, and it's already supported by the STM32Duino Arduino core, and it's even listed on your site here:

https://registry.platformio.org/tools/platformio/framework-arduinoststm32

However, I noticed that it's not in the big list of boards in PlatformIO's documentation, and the UI in the VSCode extension doesn't find it.

Having support for generic STM32C071 boards would also be nice.

It would also be helpful if someone could tell me how I go about compiling for this board before you add support for it. If I write "board = nucleo_c071rb" in my platformio.ini, it doesn't work, but maybe there's a way to grab some sort of board definition from ~/.platformio/packages/framework-arduinoststm32 instead?

[DavidEGrayson]

Thank you for moving this issue to the appropriate repository.

I found PlatformIO's Custom Embedded Boards documentation and found the nucleo_g071rb.json in this repository. Here is the board JSON I came up with and stored in ~/.platformio/boards/nucleo_c071rb.json:

{
  "build": {
    "core": "stm32",
    "cpu": "cortex-m0plus",
    "extra_flags": "-DSTM32C0 -DSTM32C0xx -DSTM32C071xx",
    "f_cpu": "48000000L",
    "framework_extra_flags": {
      "arduino": "-D__CORTEX_SC=0"
    },
    "mcu": "stm32c071rbt6",
    "product_line": "STM32C071xx",
    "variant": "STM32C0xx/C071R(8-B)T"
  },
  "debug": {
    "default_tools": [
      "stlink"
    ],
    "jlink_device": "STM32C071RB",
    "onboard_tools": [
      "stlink"
    ],
    "openocd_target": "stm32c0x",
    "svd_path": "STM32C071.svd"
  },
  "frameworks": [
    "arduino",
    "cmsis",
    "stm32cube"
  ],
  "name": "Nucleo C071RB",
  "upload": {
    "maximum_ram_size": 24576,
    "maximum_size": 131072,
    "protocol": "stlink",
    "protocols": [
      "stlink",
      "jlink",
      "cmsis-dap",
      "blackmagic",
      "mbed"
    ]
  },
  "url": "https://www.st.com/en/evaluation-tools/nucleo-c071rb.html",
  "vendor": "ST"
}

Then I used this platform.ini file in my project:

[env:nucleo_c071rb]
platform = ststm32
board = nucleo_c071rb
framework = arduino

I was able to successfully build, but when I tried to upload to the board, I see that OpenOCD printed this error:

embedded:startup.tcl:28: Error: Can't find target/stm32c0x.cfg

That file was added in 2023, and the OpenOCD maintainers also merged my patch in January 2025 to add support for the STM32C071xx. OpenOCD hasn't actually tagged a new release since v0.12.0 in 2023.

Can we update PlatformIO to use the latest OpenOCD version from its master branch?

Edit: Until the latest OpenOCD is available, I was able to at least get upload working by using the STM32CubeProgrammer to modify the ST-Link chip's firmware to enable the mass storage interface, and then adding these lines to platformio.ini:

upload_protocol = mbed
upload_port = E:

[valeros]

Hi @DavidEGrayson, thanks for the PR. We’re currently not planning to extend the list of supported STM32 MCU series.

[charlescao460]

Hi @valeros , can you reveal more details about the plan of STM32 MCU series? Will the support be eventually discontinued?

[valeros]

@charlescao460 Already supported MCU series remain unaffected — packages will be updated regularly, though support for new series is on hold for now.

[DavidEGrayson]

I think if PlatformIO just updates OpenOCD, that would go a long way towards allowing users to use the later STM32 chips, without needing official support.