STM32Duino core does not do well with Maple bootloader

[fpiSTM]

Yes. MCU with USB non OTG requires a PU while USB OTG has internal PU anyway several board with it has an external PU.

[Phono]

The fact is that this toggling was done in Roger's core, and is no more done in the STM32Duino core. So I must add the few lines above before initializing the Serial port.

[fpiSTM]

This is done in the core Phono. As I said before. ..

[fpiSTM]

But I just think that you talk about a discovery pin. So in your variant you have to define it.

[Phono]

You are right, my board has the discovery pin. And this one is not automatically handled by the core.

[ag123]

hi Phono,
if you make a variant, you may like to contribute that to the core. i think many people has this board
i.e. the stm32f103rb from Olimex
https://www.olimex.com/Products/Duino/S ... e-hardware
it is a nice board, one of those features they replicated is they use a separate LDO for the ADC supply, that reduce noise
it has a micro-sd card slot on SPI2
and an on board lipo charger and power supply

[Phono]

You are right, this is a good board especially for the applications where the CAN bus is needed.

[ag123]

the only slight dislike is the use of micro pins for swd/jtag, which requires a connecting adapter and it makes some pins that has double functions less accessible there. but the rb has quite a lot of pins, so it is normally adequate at other ports

[fpiSTM]

Phono if you use the generic variant then define the USB disc pin:
#define USB_DISC_PIN PYn


You can use the hal_conf_extra.h or the build_opt.h to do this

[stevestrong]

Just for reference, the USB_DISC pin toggling is implemented here:
https://github.com/stm32duino/Arduino_C ... #L131-L152