STM32: Missing peripherals for bluepill_f103c8 in targets.json

[cesarvandevelde]

Description

I've encountered a problem using the CAN peripheral on the STM32 bluepill_f103c8 board. The following code does not compile when the target is set to bluepill_f103c8, but it does compile when the target is set to nucleo_f103rb:

#include <mbed.h>
#include <CAN.h>

CAN can(PB_8, PB_9);

int main() {
  while (true) {}
  return 0;
}

I'm using the PlatformIO toolchain to compile the code, with the following platformio.ini file:

[env:stm32]
platform = ststm32
board = bluepill_f103c8
;board = genericSTM32F103C8
;board = nucleo_f103rb
framework = mbed
lib_ignore = mbed-LWIP, mbed-mbedtls
build_flags =
  -D PIO_FRAMEWORK_MBED_RTOS_PRESENT

There should not be a difference between the two targets, the only difference between the STM32F103RB and the STM32F103C8 is that the former has more flash memory.

Some digging revealed that FEATURE_CAN is not defined on bluepill_f103c8, hence why the CAN class is not defined. I managed to get the target to build by making the following modifications:

platformio.ini:

[env:stm32]
platform = ststm32
board = bluepill_f103c8
;board = genericSTM32F103C8
;board = nucleo_f103rb
framework = mbed
lib_ignore = mbed-LWIP, mbed-mbedtls
build_flags =
  -D PIO_FRAMEWORK_MBED_RTOS_PRESENT
  -D FEATURE_CAN=1

variants/BLUEPILL_F103C8/BLUEPILL_F103C8.json, line 1377:
Added "DEVICE_CAN=1".

    "symbols": [
        "DEVICE_SLEEP=1",
        "DEVICE_PWMOUT=1",
        "TRANSACTION_QUEUE_SIZE_SPI=2",
        ...
        "DEVICE_INTERRUPTIN=1",
        "TARGET_LIKE_MBED",
        "DEVICE_CAN=1"
    ],

targets/targets.json, line 3680:
Copied the device_has_add key from the NUCLEO_F103RB target.

    "BLUEPILL_F103C8": {
        "inherits": ["FAMILY_STM32"],
        "core": "Cortex-M3",
        "default_toolchain": "GCC_ARM",
        "extra_labels_add": ["STM32F1", "STM32F103C8"],
        "supported_toolchains": ["GCC_ARM"],
        "device_has_add": ["CAN", "SERIAL_FC", "SERIAL_ASYNCH", "FLASH"],
        "device_has_remove": ["RTC", "STDIO_MESSAGES"]
    },

Issue request type

[ ] Question
[ ] Enhancement
[X] Bug

[0xc0170]

I would assume it might be that it was not tested and not enabled but might be a different reason

cc @zgoda Please review

[0xc0170]

cc @ARMmbed/team-st-mcd

[ciarmcom]

ARM Internal Ref: MBOTRIAGE-1472

[adustm]

Hello,
Bluepill platform is not supported by ST team.
CAN is supported on NUCLEO_F103RB within mbed-os.

I confirm that the code for STM32F103C8 is compatible with the one on STM32F103RB.
Adding "CAN" in targets.json should work (CAN pins are already present in

mbed-os/targets/TARGET_STM/TARGET_STM32F1/TARGET_BLUEPILL_F103C8/PeripheralPins.c

Line 173 in 8292aff

const PinMap PinMap_CAN_RD[] = {

)

The community is free to create the pull request to add "CAN" in targets.json.
ST team cannot do it because we cannot validate it.

Kind regards

[0xc0170]

Thanks @adustm for the detailed info about F103 MCU.

@cesarvandevelde feel free to send PR adding CAN for the target

[cesarvandevelde]

Thanks for the follow-up, @0xc0170 and @adustm, I'll take a look and see what I can do.
I'll need a bit of time to figure out how/where the mbed and PlatformIO toolchains interact with one another though, just to make sure I don't accidentally break things... :)

[jeromecoutant]

I think we can close this issue, and follow pull requests now ?

[screamerbg]

@jeromecoutant Agreed.