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ASten.1
Associate
June 16, 2022
Solved

STM32L432KC CAN bus does not transmit

  • June 16, 2022
  • 3 replies
  • 2289 views

Hi! I have been trying for a while now to get the STM32L432KC to transmit on a CAN bus but to no avail. I have been using a MCP2551 as tranciver and i know it works since i have gotten it to work with a STM32L476 board. The interesting part is that when i try and measure the output on P12 (D2/CAN1_TX this is on the MCU) with an oscilloscope all i get is a high signal and no message out (Have tried this with the MCP2551 connected and disconnected same result). I have run the same code (almost same) on a STM32L476 with a MCP2551 and it works. I have no idea what the problem could be. Is it something in my code that does not work? I'm using the stm32Cube IDE auto code generation. Most of the code i have written is between lines 78 - 79.

Thanks in advance!

/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file : main.c
 * @brief : Main program body
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2022 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 variables ---------------------------------------------------------*/
CAN_HandleTypeDef hcan1;
 
UART_HandleTypeDef huart1;
 
/* USER CODE BEGIN PV */
CAN_TxHeaderTypeDef txHeader;
CAN_RxHeaderTypeDef rxHeader;
uint32_t txMailbox;
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CAN1_Init(void);
static void MX_USART1_UART_Init(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_CAN1_Init();
 MX_USART1_UART_Init();
 /* USER CODE BEGIN 2 */
 
 txHeader.StdId = 0x123;
 txHeader.IDE = CAN_ID_STD;
 txHeader.RTR = CAN_RTR_DATA;
 txHeader.DLC = 8;
 
 HAL_CAN_Start(&hcan1);
 
 uint8_t msg[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x01};
 
 HAL_CAN_AddTxMessage(&hcan1, &txHeader, msg, &txMailbox);
 
 /* USER CODE END 2 */
 
 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
 while (1)
 {
 /* 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_MSI;
 RCC_OscInitStruct.MSIState = RCC_MSI_ON;
 RCC_OscInitStruct.MSICalibrationValue = 0;
 RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
 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_MSI;
 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_0) != 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 = 2;
 hcan1.Init.Mode = CAN_MODE_NORMAL;
 hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
 hcan1.Init.TimeSeg1 = CAN_BS1_2TQ;
 hcan1.Init.TimeSeg2 = CAN_BS2_1TQ;
 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 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.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
 if (HAL_UART_Init(&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 Ports Clock Enable */
 __HAL_RCC_GPIOA_CLK_ENABLE();
 
}
 
/* 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 */
 

This topic has been closed for replies.
Best answer by ASten.1

Changing

hcan1.Init.AutoWakeUp = DISABLE;

to ENABLE solved my issue.​

3 replies

Tooky
Associate
June 16, 2022

Does it mean that the receive is working correctly (Sent by an external node) ? Using the right speed and so on.

ASten.1
ASten.1Author
Associate
June 16, 2022

I have not tested is as extensively but when i did i still got nothing. Something to add to the above is that i have tested this (The Tx part of this problem) on 3 different STM32L432KC boards so it must be a config mistake on my part but i cant find anything. I have a CAN network connected to a PCAN-USB so i can both send and receive CAN messages through the PCAN-view software on a pc and have confirmed there that messages sent from the STM32L476 is detected

ASten.1
ASten.1AuthorBest answer
Associate
June 16, 2022

Changing

hcan1.Init.AutoWakeUp = DISABLE;

to ENABLE solved my issue.​