ChibiOS Free Embedded RTOS

Hi,
I am using F401. Last time i was using UART for serial print and it was working fine. But unfortunately i lost my code. So, i was doing that again.
So, i configure Serial driver but now it is not working. I checked demo code for F401 nucleo code. For that also serial driver is not working.
I checked my USB2Serial device and it is working fine.
how to debug this one.

I am using SD1 driver and connected PA2 and PA3 pin of nucleo.

Hi,

Use an oscilloscope or a logic analyzer and see if the UART TX generates the frames.

Giovanni

If we are talking about STM32F401xE on PA2 and PA3 there is SD2 already connected to ST-Link and virtualized over USB

The ST dev boards have various jumpers and solder links on some of the I/O - sometimes these need changing. Check the circuit for the relevant board. (RoccoMarco obviously has - probably you can route these signals direct to pins if you want)

(Serial driver for the F407 certainly works fine, so I think you're looking for a hardware problem)

Problem is solved now.
As RoccoMarco and steved suggested, i was re-connecting USB to serial to the pins which were connected to ST-Link on board.