I'm experimenting with bluepill, I have set USART3 to DMA circular mode. I've enabled the HAL_UARTEx_ReceiveToIdle_DMA in the main() and then again in the HAL_UARTEx_RxEventCallback, the half complete receive callback is disabled in both main() and in the RxEventCallback. When I start up the bluepill with a serial terminal on windows via uart3, it works fine; but if I unplug the serial line from PC (with the bluepill on) and then plug it back to PC, the uart3 won't receive anything (even though I can see the PC sending bytes on the RX line with a scope). I've placed a breakpoint inside the RxEventCallback, and it won't trigger after uplugging and plugging the serial line back. What's the problem here?
