Antoniolinux B.

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10 years ago.

stm32L152, serial4 and serial 5

Hi to all i have this strange situation i write this code

#include "mbed.h"
 //Serial pc(PC_10,PC_11); //Serial 4  TX,  RX   ko
  Serial pc(PB_10,PB_11); //Serial 3  TX,  RX  //ok
 //Serial pc(PC_12,PD_2); //Serial 5  TX,  RX  //ko


DigitalOut myled(LED1);

int main() {
  int i = 1;
  pc.printf("Hello World !\n");
  while(1) {
      wait(1);
     pc.printf("This program runs since %d seconds.\n", i++);
      myled = !myled;
  }
}

if i use Serial 3 all work well, if i use serial 4 or serial 5 don't work, can you give where is the error ?

can you help me?

best regards A.

2 Answers

bco stm
10 years ago.

If this is the case (viewing the serial output on USB), you can also add a wire from the SERIALn_TX pin you want to the CN3-RX connector. And one wire between the SERIALn_RX pin to the CN3-TX connector.

Accepted Answer
Brian Daniels
10 years ago.

Hi Antoniolinux,

Are you trying to view this serial output through your serial console via the USB interface on the NUCLEO board?

If so then Serial 4 and 5 won't work because they aren't attached to the interface chip on the NUCLEO board. To read from Serial 4 and 5 you'll need an external serial adapter or another microcontroller/mbed.

Hope that helps, Brian