Arduino for STM32

Solved my issue. Not sure what my initial problem was. For those with similar issues - here is a basic example of canfd with g4:

https://github.com/owennewo/youtube_can ... c/main.cpp
https://github.com/owennewo/youtube_can ... pleCan.cpp

There is something very wrong with FDCAN1 peripheral registers for my board. It is like they are unsettable (or badly mapped).
For instance if I call init HAL_FDCAN_Init with mode=FDCAN_MODE_INTERNAL_LOOPBACK:
uint32_t cccr = READ_REG(FDCAN1->CCCR);
Serial.print("cccr - before: "); Serial.println ...

I've made a first attempt at getting a "hello world" send/receive. The `HAL_FDCAN_AddMessageToTxFifoQ()` returns HAL_OK but I don't see the CAN_H and CAN_L lines moving from midpoint (2V) on the scope and the polling receive also finds no message. I've tried `FDCAN_MODE_NORMAL` and `FDCAN_MODE ...

TLDR: Any advice, links to getting FDCAN1 working on stm32g431 using stm32duino appreciated. I'm coding in PlatformIO but use Cube IDE as a reference.

Some of the newer stm32 chips come with FDCAN instead of CAN. I suspect I'm not interested with additional benefits of FDCAN for my modest robotics ...

mlundin - thankyou, thankyou, thankyou!

So that daughterboard TX is connected to mainboard RX and was holding high. Makes sense.

For some reason I'd given up on using the USB for printf - but it seems to work! I'll be putting my ftdi back in the draw and using USB.

For completeness here are the ...

I'm in the process of adding the b-g431b-esc1 disco done kit to stm32duino, PR here:
https://github.com/stm32duino/Arduino_Core_STM32/pull/1236/files

The new variant mostly works but I'm having trouble with Serial2 RX. I'm not sure if it is a hardware fault / soldering fault / or pin setup fault ...