CAN Loopback Test using STM32 NUCLEO-L452RE

OH · ‎2025-09-15

It seems like the program is getting stuck in the Error_Handler loop and not coming out. Could there be a problem with my code?

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2025 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"
#include "can.h"
#include "usart.h"
#include "gpio.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 */

/* USER CODE END PD */

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

/* USER CODE END PM */

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

/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef TxHeader;
CAN_RxHeaderTypeDef RxHeader;
uint8_t TxData[8];
uint8_t RxData[8];
uint32_t TxMailbox;
uint8_t button_pressed_flag = 0;
uint8_t message_received_flag = 0;

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* 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_USART2_UART_Init();
  MX_CAN1_Init();
  /* USER CODE BEGIN 2 */
  // 1. CAN 수신 필터 설정 (Loopback에서도 필수는 동일)
    CAN_FilterTypeDef canfilterconfig;
    canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
    canfilterconfig.FilterBank = 0;
    canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
    canfilterconfig.FilterIdHigh = 0x0000;
    canfilterconfig.FilterIdLow = 0x0000;
    canfilterconfig.FilterMaskIdHigh = 0x0000;
    canfilterconfig.FilterMaskIdLow = 0x0000;
    canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
    canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;

    if (HAL_CAN_ConfigFilter(&hcan1, &canfilterconfig) != HAL_OK)
    {
        Error_Handler();
    }

    // 2. CAN 통신 시작
    if (HAL_CAN_Start(&hcan1) != HAL_OK)
    {
        Error_Handler();
    }

    // 3. CAN 수신 메시지 알림(인터럽트) 활성화
    if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
    {
        Error_Handler();
    }

    // 4. 전송할 메시지 헤더 기본 설정
    TxHeader.IDE = CAN_ID_STD;
    TxHeader.StdId = 0x123;         // 메시지 ID
    TxHeader.RTR = CAN_RTR_DATA;
    TxHeader.DLC = 1;               // 데이터 길이 (1바이트)
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	  // 1. 버튼이 눌렸으면 메시지 전송
	      if (button_pressed_flag == 1)
	      {
	        button_pressed_flag = 0; // 플래그 초기화

	        TxData[0]++; // 보낼 때마다 데이터 1씩 증가

	        if (HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailbox) != HAL_OK)
	        {
	          Error_Handler();
	        }
	      }

	      // 2. 메시지가 수신되었으면 LED 토글
	      if (message_received_flag == 1)
	      {
	        message_received_flag = 0; // 플래그 초기화
	        HAL_GPIO_TogglePin(LD2_GPIO_Port, LD2_Pin); // 녹색 LED 깜빡이기
	      }
    /* 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};

  /** Configure the main internal regulator output voltage
  */
  if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 64;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 1;
  RCC_OscInitStruct.PLL.PLLN = 10;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  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_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */
/**
  * @brief  CAN 메시지 수신 완료 시 호출되는 콜백 함수
  */
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
  if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData) == HAL_OK)
  {
    // 수신된 ID가 내가 보낸 ID와 일치하는지 확인
    if (RxHeader.StdId == 0x123)
    {
      message_received_flag = 1; // 수신 플래그 설정
    }
  }
}
/**
  * @brief  외부 인터럽트(버튼) 발생 시 호출되는 콜백 함수
  */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
  if (GPIO_Pin == B1_Pin)
  {
    button_pressed_flag = 1; // 버튼 플래그 설정
  }
}
/* 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)
  {
	  // 오류 발생 시 녹색 LED가 매우 빠르게 깜빡이도록 설정
	      HAL_GPIO_TogglePin(LD2_GPIO_Port, LD2_Pin);
	      HAL_Delay(100);
  }
  /* 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.
  *   file: pointer to the source file name
  *   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 */

mƎALLEm · ‎2025-09-15

Hello @OH and welcome to the St community,

You didn't share the CAN configuration? The GPIOs configuration of Tx/Rx? and you didn't tell on which Error_Handler() it was stuck? which line?

You can also refer to this article: Guide to CAN (bxCAN/CAN2.0) configuration in Loop back mode on STM32 MCUs

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