How to setup UART on STM32 Nucleo board for a peripheral UART device?

516 views Asked by At

What I've been trying to do is send UART communications from an STM32 L152RE Nucleo board to an ESP32, however when I attempt to send these communications I get nothing on the ESP serial monitor. What I am able to see is the STM32 sending messages to its own serial monitor which is great but not what I want.

What I've read so far is that UART 2 is connected to ST-Link so that it can do specifically what I've been witnessing and it explains how this can be reconfigured to allow for the messages to be sent to a peripheral UART device but I'm not sure exactly how to do that.

So in the picture below it says to do this I need to "turn off" SB13 and SB14 and "turn on" SB62 and SB63. I don't really understand how to interpret that, other than to mean "remove resistors from SB13 and SB14 and Place them on SB62 and SB63", is this correct? STM32 L152RE UART

I know there are another set of UART pins on the board, can I use those instead somehow?

1

There are 1 answers

0
Blue On

Your guess ist correct. "SB" means "Solder Bridge". It is just a pair of pads which can be connected with a solder ball, like a simple jumper. Setting SB13 to ON means to connect the pads with a solder ball, setting SB62 to OFF means to remove an existing solder ball connection.

Using a different USART is even easier. Have a look at the STM32L151xE Datasheet to find out that e.g. USART1 is available on pins PA9 (TX) and PA10 (RX). According to user manual of the NUCLEO-L152RE board these pins are available on the ST morpho connector CN10: PA9 at Pin 21 and PA10 at Pin 33.