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CAN Transmit mailbox callback function understanding
Hi
My board is STM32F407G so I want to understand the tx mailbox callback once interrupt hit I am sharing project in which I am sending CAN1 to CAN2 and CAN2 to CAN1 in loop back mode same ID.
So rxindication is working fine and this is the project I got from one of your technical executive ,so how will "hcan->TxMailbox0CompleteCallback(hcan);" get called because in above line we are clearing "
/* Clear the Transmission Complete flag (and TXOK0,ALST0,TERR0 bits) */
__HAL_CAN_CLEAR_FLAG(hcan, CAN_FLAG_RQCP0);"
which also clears "if ((tsrflags & CAN_TSR_TXOK0) != 0U)" TXOK0 bit also so if condition will not satisfy . please guide me
/* Transmit Mailbox empty interrupt management *****************************/
if ((interrupts & CAN_IT_TX_MAILBOX_EMPTY) != 0U)
{
/* Transmit Mailbox 0 management *****************************************/
if ((tsrflags & CAN_TSR_RQCP0) != 0U)
{
/* Clear the Transmission Complete flag (and TXOK0,ALST0,TERR0 bits) */
__HAL_CAN_CLEAR_FLAG(hcan, CAN_FLAG_RQCP0);
if ((tsrflags & CAN_TSR_TXOK0) != 0U)
{
/* Transmission Mailbox 0 complete callback */
#if USE_HAL_CAN_REGISTER_CALLBACKS == 1
/* Call registered callback*/
hcan->TxMailbox0CompleteCallback(hcan);
#else
/* Call weak (surcharged) callback */
HAL_CAN_TxMailbox0CompleteCallback(hcan);
#endif /* USE_HAL_CAN_REGISTER_CALLBACKS */
}
/* 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;
CAN_HandleTypeDef hcan2;
/* USER CODE BEGIN PV */
CAN_FilterTypeDef sFilterConfig;
__IO uint32_t i = 0;
// CAN1
CAN_TxHeaderTypeDef CAN1_TxHeader;
CAN_RxHeaderTypeDef CAN1_RxHeader[9];
uint8_t CAN1_TxData[2] = {0};
uint8_t CAN1_RxData[2] = {0};
uint32_t CAN1_TxMailbox;
uint32_t CAN1_Tx_ID_List[3] = {0x501,0x502,0x503};
__IO uint8_t CAN1_Rx_cnt = 0;
// CAN2
CAN_TxHeaderTypeDef CAN2_TxHeader;
CAN_RxHeaderTypeDef CAN2_RxHeader[9];
uint8_t CAN2_TxData[2] = {0};
uint8_t CAN2_RxData[2] = {0};
uint32_t CAN2_TxMailbox;
uint32_t CAN2_Tx_ID_List[3] = {0x501,0x502,0x503};
__IO uint8_t CAN2_Rx_cnt = 0;
/* 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_CAN2_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_CAN2_Init();
/* USER CODE BEGIN 2 */
sFilterConfig.FilterBank = 0;
sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
sFilterConfig.FilterIdHigh = 0x0000;
sFilterConfig.FilterIdLow = 0x0000;
sFilterConfig.FilterMaskIdHigh = 0x0000;
sFilterConfig.FilterMaskIdLow = 0x0000;
sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
sFilterConfig.FilterActivation = ENABLE;
sFilterConfig.SlaveStartFilterBank = 1;
if(HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig) != HAL_OK)
{
/* Filter configuration Error */
Error_Handler();
}
sFilterConfig.FilterBank = 1;
sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK;
sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;
sFilterConfig.FilterIdHigh = 0x0000;
sFilterConfig.FilterIdLow = 0x0000;
sFilterConfig.FilterMaskIdHigh = 0x0000;
sFilterConfig.FilterMaskIdLow = 0x0000;
sFilterConfig.FilterFIFOAssignment = CAN_RX_FIFO0;
sFilterConfig.FilterActivation = ENABLE;
sFilterConfig.SlaveStartFilterBank = 1;
if(HAL_CAN_ConfigFilter(&hcan2, &sFilterConfig) != HAL_OK)
{
/* Filter configuration Error */
Error_Handler();
}
if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
{
/* Notification Error */
Error_Handler();
}
if (HAL_CAN_ActivateNotification(&hcan2, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
{
/* Notification Error */
Error_Handler();
}
CAN1_TxHeader.ExtId = CAN2_TxHeader.ExtId = 0x01;
CAN1_TxHeader.RTR = CAN2_TxHeader.RTR = CAN_RTR_DATA;
CAN1_TxHeader.IDE = CAN2_TxHeader.IDE = CAN_ID_STD;
CAN1_TxHeader.DLC = CAN2_TxHeader.DLC = 2;
CAN1_TxHeader.TransmitGlobalTime = CAN2_TxHeader.TransmitGlobalTime = DISABLE;
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
CAN1_TxHeader.StdId = CAN1_Tx_ID_List[i];
CAN1_TxData[0] ++;
CAN1_TxData[1] --;
if (HAL_CAN_AddTxMessage(&hcan1, &CAN1_TxHeader, CAN1_TxData, &CAN1_TxMailbox) != HAL_OK)
{
/* Transmission request Error */
Error_Handler();
}
HAL_Delay(10);
CAN2_TxHeader.StdId = CAN2_Tx_ID_List[i];
if (HAL_CAN_AddTxMessage(&hcan2, &CAN2_TxHeader, CAN2_TxData, &CAN2_TxMailbox) != HAL_OK)
{
/* Transmission request Error */
Error_Handler();
}
HAL_Delay(10);
i++;
if (i == 3) i = 0;
/* 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_SCALE1);
/** 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 = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 8;
RCC_OscInitStruct.PLL.PLLN = 168;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
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_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
/**
* @brief CAN1 Initialization Function
* 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 = 4;
hcan1.Init.Mode = CAN_MODE_LOOPBACK;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_15TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_5TQ;
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 */
if (HAL_CAN_Start(&hcan1) != HAL_OK)
{
/* Start Error */
Error_Handler();
}
/* USER CODE END CAN1_Init 2 */
}
/**
* @brief CAN2 Initialization Function
* None
* @retval None
*/
static void MX_CAN2_Init(void)
{
/* USER CODE BEGIN CAN2_Init 0 */
/* USER CODE END CAN2_Init 0 */
/* USER CODE BEGIN CAN2_Init 1 */
/* USER CODE END CAN2_Init 1 */
hcan2.Instance = CAN2;
hcan2.Init.Prescaler = 4;
hcan2.Init.Mode = CAN_MODE_LOOPBACK;
hcan2.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan2.Init.TimeSeg1 = CAN_BS1_15TQ;
hcan2.Init.TimeSeg2 = CAN_BS2_5TQ;
hcan2.Init.TimeTriggeredMode = DISABLE;
hcan2.Init.AutoBusOff = DISABLE;
hcan2.Init.AutoWakeUp = DISABLE;
hcan2.Init.AutoRetransmission = DISABLE;
hcan2.Init.ReceiveFifoLocked = DISABLE;
hcan2.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN CAN2_Init 2 */
if (HAL_CAN_Start(&hcan2) != HAL_OK)
{
/* Start Error */
Error_Handler();
}
/* USER CODE END CAN2_Init 2 */
}
/**
* @brief GPIO Initialization Function
* None
* @retval None
*/
static void MX_GPIO_Init(void)
{
/* 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_GPIOB_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
/* Get RX message */
if(hcan->Instance == CAN1)
{
if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &CAN1_RxHeader[CAN1_Rx_cnt++], CAN1_RxData) != HAL_OK)
{
/* Reception Error */
Error_Handler();
}
if(CAN1_Rx_cnt == 9) CAN1_Rx_cnt = 0;
}
else if(hcan->Instance == CAN2)
{
if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &CAN2_RxHeader[CAN2_Rx_cnt++], CAN2_RxData) != HAL_OK)
{
/* Reception Error */
Error_Handler();
}
if(CAN2_Rx_cnt == 9) CAN2_Rx_cnt = 0;
}
}
/* 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.
* 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 */