Arduino for STM32

You haven't modified PeripheralPins.c, but its default configuration might interfere with your USART2 setup. I recommend manually defining pin mappings for USART2 in `variant_mydevice.h`. #define PA2_ALT_FUNC STM_PIN_DATA(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_USART2) #define PA3_ALT_FUNC STM_PIN_DAT...