STM32F411RE CAN Communication Project Issue

[nwnd]

Hello,

I am trying to build a part of the project.I want my three microcontrollers to communicate with each other via CANBus.What i am trying to achieve in this part is reading the digital sensor value from my hall effect sensor and sending this information to the other controller but for now just to see if it is working i am using a Waveshare USB-CAN A,CANBus adapter before conencting the second controller to observe if the project is working so far.I am using a MCP 2551 transcevier and I also connected the 120 ohm resistor between the CAN H and CAN L.I checked the resistance with my multimeter and I get 60 ohms in between them,as i should.

 The problem is when I click the debugger even the LED that i connected to test how far my code goes in debug never lights up.It doesn't even blink for the first line of code int main().I don't understand the reason behind it.It might be about the CAN and adapter settings,clock configuration etc. but i can't tell for sure.Just to let you know,I also checked the voltage values to see if my sensor and transcevier gets the correct voltages and they do.I also don't think it is an issue but I connect the adapter and the controller to the same PC.There is no data showing in the adapter and its CAN H and CAN L lights don't even light up meaning it doesn't most probably detect them.

I can give you more details or share more photos if you wish.I'm a begginer who is trying to learn through videos and forums so I'd really appriciate it if you can help me understand what is wrong and teach me how to fix it.

/* 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"

/* 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 ---------------------------------------------------------*/
CAN_HandleTypeDef hcan1;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CAN1_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

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

CAN_TxHeaderTypeDef TxTransmitter;
uint8_t count;
uint8_t TxData[8];
uint32_t TxMailbox;
uint8_t trunk_status;

/* USER CODE END 0 */

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

  /* USER CODE BEGIN 1 */
	HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, GPIO_PIN_SET); HAL_Delay(100);
  /* 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_CAN1_Init();
  /* USER CODE BEGIN 2 */

  CAN_FilterTypeDef canfilterconfig;
  canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
  canfilterconfig.FilterBank = 0;
  canfilterconfig.FilterFIFOAssignment = CAN_FILTER_FIFO0;
  canfilterconfig.FilterIdHigh = 0;
  canfilterconfig.FilterIdLow = 0;
  canfilterconfig.FilterMaskIdHigh = 0;
  canfilterconfig.FilterMaskIdLow = 0;
  canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
  canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
  HAL_CAN_ConfigFilter(&hcan1, &canfilterconfig);

  if (HAL_CAN_Start(&hcan1) != HAL_OK) {
       HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, GPIO_PIN_SET); // Turn on LED if CAN fails
       while (1);  // Stop program here
   }


  TxTransmitter.StdId = 0x37;

  TxTransmitter.DLC = 1;

  TxTransmitter.IDE = CAN_ID_STD;

  /* USER CODE END 2 */

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

	         // Read sensor value
	         trunk_status = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_5);

	         // Set CAN data
	         TxData[0] = trunk_status;

	         // Transmit CAN message
	         if (HAL_CAN_AddTxMessage(&hcan1, &TxTransmitter, TxData, &TxMailbox) != HAL_OK) {
	             // Transmission error (optional debug)
	        	 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, GPIO_PIN_SET);  // Turn ON LED (error)
	        	} else {
	        	    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, GPIO_PIN_RESET); // Turn OFF LED (success)

	         }

	         HAL_Delay(100);  // Send every 100ms
	     }

    /* 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
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);

  /** 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;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 84;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 2;
  RCC_OscInitStruct.PLL.PLLR = 2;
  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_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief CAN1 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_CAN1_Init(void)
{

  /* USER CODE BEGIN CAN1_Init 0 */

  /* USER CODE END CAN1_Init 0 */

  /* USER CODE BEGIN CAN1_Init 1 */

  /* USER CODE END CAN1_Init 1 */
  hcan1.Instance = CAN1;
  hcan1.Init.Prescaler = 12;
  hcan1.Init.Mode = CAN_MODE_NORMAL;
  hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
  hcan1.Init.TimeSeg1 = CAN_BS1_3TQ;
  hcan1.Init.TimeSeg2 = CAN_BS2_3TQ;
  hcan1.Init.TimeTriggeredMode = DISABLE;
  hcan1.Init.AutoBusOff = DISABLE;
  hcan1.Init.AutoWakeUp = DISABLE;
  hcan1.Init.AutoRetransmission = DISABLE;
  hcan1.Init.ReceiveFifoLocked = DISABLE;
  hcan1.Init.TransmitFifoPriority = DISABLE;
  if (HAL_CAN_Init(&hcan1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN CAN1_Init 2 */

  /* USER CODE END CAN1_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_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_10, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA10 */
  GPIO_InitStruct.Pin = GPIO_PIN_10;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : PB5 */
  GPIO_InitStruct.Pin = GPIO_PIN_5;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

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

/* USER CODE BEGIN 4 */

/* 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 */

[MHoll.2]

Hi,

welcome ti the STM32 Forum.

1) You should not used HAL_xx function before the HAL_Init() call.

2) You should use HAL_GPIO_xx function only after calling MX_GPIO_Init().

So this could explain why you don't see the LED.

For the CAN bus i don't see a obvious error, when You single step with the debugger do You get in some error state?

[nwnd]

Thank you for the warm welcome and your help.I moved that line below the functions that you mentioned and i put bunch of breakpoints to observe what is going on.My LED still doesn't light on and when I observe the code,it goes to the stm32fxx_hal.c library and it seems to be sort of stuck in some part of this library.At first,I assumed this is because of some issue with the Delay function even though my LED didn't light up either however I still deleted the delay part just to make sure and it didn't light up again.About the CAN part,since it seems like I am not even going that far in the code I can't tell yet.I changed some clock settings etc. to see if it changes anything and it didn't help also.It's safe to say that I'm a bit lost of what to do here so I'd really appreciate your insight on it.

[MHoll.2]

Ok, so Your problem is probably in the configuration of the HAL Timer.

Can You share your project (select the Project and the export General->Archive File), or if this is not possible, at least the modified main.c and the *.ioc file

[nwnd]

I attached the project file.Please let me know if you have any difficulty opening it.

[mƎALLEm]

Hello,

First, did you check with a very simple project if the LED can blink without issues?

Second, did you try the CAN in loopback? before going ahead with Normal mode, you need first to try the Loopback mode at least to check the transmit and receive, the code execution (your use case) as well as the filters in the receive. Refer to this article: Guide to CAN (bxCAN/CAN2.0) configuration in Loop back mode on STM32 MCUs