STM32 N6 FSBL USART doesn't work

[HANITALY]

Hi,

I have been trying to study how to use the N657X0 Nulceo board. 

When I tried to test the USART of the board with an FSBL project, there was no print on the serial monitor, and I could not find the reason. Could somebody check what the problem is with my project? 

I have attached my projects below.

[RomainR. · Accepted solution]

@HANITALY 

To use strlen(), the string header must be added.

#include <string.h>

To use printf, you must also redirect stdio fputc to USART1.

See the main.c file modified in attachment and the terminal result below using PC4 USART1_TX.

The printf and UART Transmit are working now.

In your code:
PC4 USART1_TX is available on AF4
PF12 USART1_RX is available on AF12

PC4 is available on MORPHO connector CN3 pin #13
PF12 is connected to Ethernet LAN8742A device on board, and it is not available on MORPHO connectors.

If you need TX and RX you can also use PD9 USART3_RX and PD8 USART3_TX on CN15 pin #35 and #37.  

Note: PE5 USART1_TX and PE6 USRT1_RX are also connected to embedded STLinkV3 Virtual COM Port.
Refer to the example below:
STM32Cube_FW_N6_V1.1.1\Projects\NUCLEO-N657X0-Q\Examples\UART\UART_Printf

Best regards,

Romain,