STM32F767 Nucleo board printf to console

Question

For the last couple of days I have been trying to get printf to work to print a debug message to a STM32CubeIDE console. However, with no luck. I have gone through numerous forum threads and discussions and none of them appear to have fully solved this weird issue that is well known.

I have just generated a brand new project with STM32CubeMX and used a default configuration for the Nucleo board. I am just using USB cable with build in ST-link to program the device.

What I have been suggested to do so far is to add a few lines of code that apparently should have fixed the issue but it didint:

#ifdef __GNUC__
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif


PUTCHAR_PROTOTYPE
{
  HAL_UART_Transmit(&huart3, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}

I have also included :

#include "stdio.h"

The actual code:

int main(void)
{
  /* USER CODE BEGIN 1 */
    uint8_t uart3_data[20] = "hello from uart3";
    uint8_t uart1_data[20] = "hello from uart1";
  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART3_UART_Init();
  MX_USART1_UART_Init();
  MX_TIM10_Init();
  /* USER CODE BEGIN 2 */
  HAL_TIM_Base_Start_IT(&htim10);
  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
      //Toggle_leds(GPIOB,GPIO_PIN_0,100);

      HAL_Delay(1000);
      printf("UART Printf Example: retarget the C library printf function to the UART \n\r");
      printf("** Test finished successfully. ** \n\r");
      HAL_UART_Transmit(&huart3,uart3_data, sizeof(uart3_data), 50); // just to see what happens

      //HAL_UART_Transmit(&huart1,uart1_data, sizeof(uart1_data), 50); // just to see what happens


  }
  /* USER CODE END 3 */
}

When I open up a terminal and connect to the device , I can see the messages coming as expected: enter image description here

However, I cannot understand why I am not able to see messages dispalyed on the stm32cubeIDE console. Am I missing some additional configuration?

STM32CubeIDE console displays the output of commands run locally on your PC. It's not meant to display serial output coming from the MCU. Either continue to use an external program or search and install an Eclipse add-in (like TM Terminal). — Codo

Lukas Petrikas Lukas Petrikas · Accepted Answer · 2021-01-11T05:56:31

I have managed to get it working. Those who are having the same problem, just follow these simple steps:

Add a custom _write function to syscalls.c or even main.c:

int _write(int file, char *ptr, int len)
{
  /* Implement your write code here, this is used by puts and printf for example */
  int i=0;
  for(i=0 ; i<len ; i++)
    ITM_SendChar((*ptr++));
  return len;
}

In the debug configuration, enable the SWV tracing and set the core clock to the SYSCLK of your device. (See the image below)

Debug configuration

Debug your code and go to Windows -> Show view -> SWV -> SWV ITM Data console

Now you should have enabled SWV data console, check the image below: SWV ITM Data console

Open up the SWV ITM Data console settings and make sure the port 0 is ticked(See image below): Enable port 0

5.When you run the code, make sure start tracing is enabled: Enable start tracing

Have fun printing message to the console

Detailed guide on youtube can be found here: https://www.youtube.com/watch?v=Ti-1X8HfVrc&ab_channel=RADAS

Unfortunately, there is still a hassle using this method. everytime you debug your code, you need to start tracing. There must be a simple method to display a message in the console without using the tracing

STM32F767 Nucleo board printf to console

1 Answers