UART Transfer failed - STM32C031C6 UART1 - NUCLEO-C031C6

[dramanovic]

Hi all, 

I am trying to display output through uart in a terminal doing every step of the following tutorial:

How to redirect the printf function to a UART for ... - STMicroelectronics Community

However i still do not receive any terminal output using the NUCLEO-C031C6... I changed the UART2 from the tutorial to the corresponding UART1 of the NUCLEO Board and building and running the project works without issues!

However, still no display on Serial Terminal.

David

[Tesla DeLorean · Accepted solution]

We can't see your code, you have it on GitHub?

https://www.st.com/resource/en/user_manual/dm00834035.pdf

SB = Solder bridges, Solder or Zero-Ohm Resistor

Check SB27/SB32=ON (UART2 PA2/PA3) vs SB31/SB33=ON (UART1 PB6/PB7)

Only enable ONE UART, and do basic send character to test. Make sure baud rates match on UART vs VCP COM Port

[Andrew Neil]

---

@dramanovic wrote:

I am trying to display output through uart in a terminal doing every step of the following tutorial:

How to redirect the printf function to a UART for ... - STMicroelectronics Community

---

As @Tesla DeLorean said, before getting printf involved, make sure you can just send characters directly from the UART.

[dramanovic]

Hi, thanks!

I have configured my UART like it is demonstrated in the tutorial. Asynchronous with a baud rate of 115200 and 8 Bits(including Parity),1 Stop bit.Then generated the corresponding code using the "Device configuration Tool Code Generation". When debugging and running the following code, nothing appears in the serial output connection with the same baud rate. As a COM Port, it is displayed "ST-Link VCP Ctrl". I have connected my board only via micro-usb cable to the laptop. THE VCP TX and RX are mapped to PA2/3. USART1_TX/RX are mapped to PA0/1.

Any recommendations?

The following code describes my issue:

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

COM_InitTypeDef BspCOMInit;

UART_HandleTypeDef huart1;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);
/* USER CODE BEGIN PFP */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t tx_buff[]={65,66,67,68,69,70,71,72,73,74};
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{

  /* USER CODE BEGIN 1 */

  /* 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_USART1_UART_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Initialize leds */
  BSP_LED_Init(LED_GREEN);

  /* Initialize USER push-button, will be used to trigger an interrupt each time it's pressed.*/
  BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);

  /* Initialize COM1 port (115200, 8 bits (7-bit data + 1 stop bit), no parity */
  BspCOMInit.BaudRate   = 115200;
  BspCOMInit.WordLength = COM_WORDLENGTH_8B;
  BspCOMInit.StopBits   = COM_STOPBITS_1;
  BspCOMInit.Parity     = COM_PARITY_NONE;
  BspCOMInit.HwFlowCtl  = COM_HWCONTROL_NONE;
  if (BSP_COM_Init(COM1, &BspCOMInit) != BSP_ERROR_NONE)
  {
    Error_Handler();
  }

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	  /*printf("Hello World\n\r");*/

	  uint8_t Test[] = "Hello World !!!\r\n"; //Data to send
	  HAL_UART_Transmit(&huart1,Test,sizeof(Test),10);// Sending in normal mode
	  HAL_Delay(1000);
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSE;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief USART1 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_USART1_UART_Init(void)
{

  /* USER CODE BEGIN USART1_Init 0 */

  /* USER CODE END USART1_Init 0 */

  /* USER CODE BEGIN USART1_Init 1 */

  /* USER CODE END USART1_Init 1 */
  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  huart1.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart1.Init.ClockPrescaler = UART_PRESCALER_DIV1;
  huart1.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetTxFifoThreshold(&huart1, UART_TXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_SetRxFifoThreshold(&huart1, UART_RXFIFO_THRESHOLD_1_8) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_UARTEx_DisableFifoMode(&huart1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART1_Init 2 */

  /* USER CODE END USART1_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOF_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pins : PB8 PB9 */
  GPIO_InitStruct.Pin = GPIO_PIN_8|GPIO_PIN_9;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.Alternate = GPIO_AF6_I2C1;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
/**
  * @brief  Retargets the C library printf function to the USART.
  * @PAram  None
  * @retval None
  */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @PAram  file: pointer to the source file name
  * @PAram  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

[Andrew Neil]

You have this twice:

#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)

but you never actually define the __io_putchar function!

Take another look at the Knowledgebase article - the function definition is at the end of the code shown:

/* USER CODE BEGIN 4 */
/**
  * @brief  Retargets the C library printf function to the USART.
  *   None
  * @retval None
  */
PUTCHAR_PROTOTYPE
{
  /* Place your implementation of fputc here */
  /* e.g. write a character to the USART1 and Loop until the end of transmission */
  HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xFFFF);

  return ch;
}

/* USER CODE END 4 */

But, again, before you do that, make sure you can just write direct to the UART

[Pavel A.]

So: is the "COM1" of BSP USART1 or another U(S)ART?  Which of them is  connected to the VCP of ST-LINK?

[Karl Yamashita]

---

@dramanovic wrote:

I changed the UART2 from the tutorial to the corresponding UART1 of the NUCLEO Board

---

The VCP is on UART2. If you changed to UART1, how are you connecting UART1 to the serial program? Using a USB to TTL Serial interface?