STM32L496ZGT6PU STLINK UART communication not working

[RiccardoMilici]

Goodmorning

I have a new STM32L496ZGT6PU board and I'm currently trying to print a message on the debugger serial terminal, I've followed many official guides step by step failing every time.

In particular, I perform the following:

1. Connect the board through a USB type micro-B cable to my laptop (USB PWR connector).
2. Create a new STM32 project, selecting the NUCLEO-L496ZG-P board from the board selector -> target language C++ -> initialize the peripherals with their default mode (YES).
3. In Pinout & Configuration I go to Connectivity -> USART2 -> Mode Asynchronous and leave the default values.
4. Device Configuration Tool Code Generation
5. In Src/main.c simply write the following two lines of code in the main() function:

/* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
	  HAL_UART_Transmit(&huart2, (uint8_t*)"Ciao ", 6, 100);
	  HAL_Delay(1000);
  }
  /* USER CODE END 3 */

Then I build the project and start Debug keeping the default settings.

During the debug I create a new command shell console with

• Connection Type: Serial Port
• Serial port: COM6 (my PC seems to correctly recognize the STLINK on this COM port)
• Baudrate: 115200
• Data size: 8
• Parity: none
• Stop bits: 1

By clicking on "resume", the code seems to run, but nothing pops on the serial console.

 I tried to use an equal board, change the cable, and change USART interface but this didn't solve the problem.

[Imen.D]

Hello @RiccardoMilici ,

Check your pins configuration and I recommend you follow these articles :

• How to redirect the printf function to a UART for ... - STMicroelectronics Community
• Getting started with UART - stm32mcu

[Andrew Neil · Accepted solution]

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@RiccardoMilici wrote:

3. In Pinout & Configuration I go to Connectivity -> USART2 -> Mode Asynchronous and leave the default values.

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User manual says it's LPUART1 connected to the VCP:

https://www.st.com/resource/en/user_manual/um2179-stm32-nucleo144-boards-mb1312-stmicroelectronics.pdf#page=26

[mƎALLEm]

Hello, 

Simply because USART2 is not connected to STLINK virtual comport on NUCLEO-L496ZG-P board.

Based on the board schematics, you need to use LPUART1 instead:

[Andrew Neil]

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@Imen.D wrote:

Check your pins configuration and the USART2 alternate functions on which pins are mapped.

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It's LPUART1 - not USART2

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@Imen.D wrote:

I recommend you follow these articles :

• How to redirect the printf function to a UART for ... - STMicroelectronics Community
• Getting started with UART - stm32mcu

---

Yes, but they should be done in the opposite order:

• First: Getting started with UART - stm32mcu
• Then, if required: How to redirect the printf function to a UART for ... - STMicroelectronics Community

[Imen.D]

You are right, I didn't pay attention on the used board.

Thank you @Andrew Neil for pointing out to me.