51822 p08 does not work as digital output if UART is enabled

[stiebrs]

Hi, I'm trying to work out, why p08 stops working as DO if mbed Serial is used.

Code is pretty minimalistic:

#include "mbed.h"

    int main() {
        //Serial pc(p15, p16);   
        DigitalOut myled(p8);
        myled = 1;
    }

Works perfectly fine with Serial commented out. Any ideas/comments/suggestions?

[monpetit]

What's your target board?

[monpetit]

In mbed platforms there are assigned pins already for certain functions. If you enable UART, cts and rts pins are set together, and you can't use those for GPIO. Check "PinName.h" of your target board.

RX_PIN_NUMBER = p11,
TX_PIN_NUMBER = p9,
CTS_PIN_NUMBER = p10,
RTS_PIN_NUMBER = p8,

[stiebrs]

It's a custom made board without predefined settings. Replaced prebuilt libraries with sources, remapped pins, now it works well. I was not aware of pins being hard-mapped in library sources, now I know. Thank you very much