I try to get the CAN working. But currently I'm not sure what I'm missing.
I use the STM32CubeIDE v1.18.0. The boards I use is own hardware with SN65HVD232.
The hardware seems to work well. on the picture you see the screenshot from my oscilloscope, CANTX, CANRX, CANL, CANH after calling:
HAL_CAN_AddTxMessage(&hcan1, &TxHeader, &TxData[0], &TxMailbox)
The complete code is here:
/* 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 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define TX_BUF 48
#define RX_BUF 16
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
CAN_HandleTypeDef hcan1;
UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
uint8_t u8TxBuf[TX_BUF];
uint8_t u8Message[RX_BUF];
uint8_t u8RxBuf[RX_BUF];
uint8_t u8Receive[RX_BUF];
uint8_t u8MsgAvl = 0;
uint8_t u8RxCnt = 0;
CAN_TxHeaderTypeDef TxHeader;
CAN_RxHeaderTypeDef RxHeader;
uint32_t TxMailbox = 0;
uint8_t TxData[8];
uint8_t RxData[8];
uint32_t msg_count = 0;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_CAN1_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 */
HAL_StatusTypeDef HALstat;
/* 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 */
CAN_FilterTypeDef canfilterconfig;
canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
canfilterconfig.FilterBank = 0; // anything between 0 to SlaveStartFilterBank
canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
//canfilterconfig.FilterIdHigh = 0x103<<5;
canfilterconfig.FilterIdHigh = 0x0000;
canfilterconfig.FilterIdLow = 0x0000;
//canfilterconfig.FilterMaskIdHigh = 0x1<<13;
canfilterconfig.FilterMaskIdHigh = 0x5000;
canfilterconfig.FilterMaskIdLow = 0x0;
canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
canfilterconfig.SlaveStartFilterBank = 13;
HALstat = HAL_CAN_ConfigFilter(&hcan1, &canfilterconfig);
HALstat = HAL_CAN_Start(&hcan1);
HAL_CAN_ActivateNotification(&hcan1,CAN_IT_RX_FIFO0_MSG_PENDING);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_0);
if(0 != u8MsgAvl) {
u8MsgAvl = 0;
/*clear the answer buffer*/
memset(&u8TxBuf[0], 0, TX_BUF);
/* auswerten, was in der Nachricht stand*/
switch(u8Message[0]){
case 'F':
sprintf((char*) &u8TxBuf[0],"F ok\r");
break;
case 'R':
sprintf((char*) &u8TxBuf[0],"R ok\r");
break;
case 'L':
sprintf((char*) &u8TxBuf[0],"T ok\r");
break;
case 'S':
sprintf((char*) &u8TxBuf[0],"S ok\r");
break;
case 'X':
sprintf((char*) &u8TxBuf[0],"X ok\r");
break;
case 'P':
sprintf((char*) &u8TxBuf[0],"P ok\r");
break;
}
HAL_UART_Transmit_IT(&huart2, &u8TxBuf[0], strlen((char*)u8TxBuf));
HAL_Delay(5);
}
HAL_Delay(1000);
TxHeader.DLC = 4;
TxHeader.ExtId = 0;
TxHeader.IDE = CAN_ID_STD;
TxHeader.RTR = CAN_RTR_DATA;
TxHeader.StdId = 0x104;
TxHeader.TransmitGlobalTime = DISABLE;
if (HAL_CAN_AddTxMessage(&hcan1, &TxHeader, &TxData[0], &TxMailbox) != HAL_OK)
{
Error_Handler();
}
/* 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_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 = 8;
RCC_OscInitStruct.PLL.PLLN = 168;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
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_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != 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 = 42;
hcan1.Init.Mode = CAN_MODE_NORMAL;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_1TQ;
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 USART2 Initialization Function
* @PAram None
* @retval None
*/
static void MX_USART2_UART_Init(void)
{
/* USER CODE BEGIN USART2_Init 0 */
/* USER CODE END USART2_Init 0 */
/* USER CODE BEGIN USART2_Init 1 */
/* USER CODE END USART2_Init 1 */
huart2.Instance = USART2;
huart2.Init.BaudRate = 115200;
huart2.Init.WordLength = UART_WORDLENGTH_8B;
huart2.Init.StopBits = UART_STOPBITS_1;
huart2.Init.Parity = UART_PARITY_NONE;
huart2.Init.Mode = UART_MODE_TX_RX;
huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
huart2.Init.OverSampling = UART_OVERSAMPLING_16;
if (HAL_UART_Init(&huart2) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN USART2_Init 2 */
/* USER CODE END USART2_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();
__HAL_RCC_GPIOC_CLK_ENABLE();
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_RESET);
/*Configure GPIO pin Output Level */
HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0, GPIO_PIN_RESET);
/*Configure GPIO pins : PA4 PA5 */
GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/*Configure GPIO pins : PA6 PA7 */
GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
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 : PB0 */
GPIO_InitStruct.Pin = GPIO_PIN_0;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
/*Configure GPIO pins : PC10 PC11 PC12 */
GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_NOPULL;
HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}
/* USER CODE BEGIN 4 */
/**
* @brief UART Rx IRQ function.
*
* The UART is configured to call this function for each received
* character. Here the characters will be collected until CR received.
*
*
* @PAram huart UART handle
* @retval None
*/
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
u8Receive[u8RxCnt] = u8RxBuf[0];
if(13 != u8Receive[u8RxCnt]) {
HAL_UART_Receive_IT(&huart2, &u8RxBuf[0], 1);
u8RxCnt = u8RxCnt + 1;
if(u8RxCnt >= RX_BUF) {
u8RxCnt = 0;
}
} else {
memcpy(&u8Message[0],&u8Receive[0],u8RxCnt);
u8Message[u8RxCnt] = 0;
u8MsgAvl = 1;
u8RxCnt = 0;
HAL_UART_Receive_IT(&huart2, &u8RxBuf[0], 1);
}
return;
}
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
//DBG("HAL_CAN_RxFifo0MsgPendingCallback");
if (HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &RxHeader, RxData) == HAL_OK) {
//DBG("Got message %lu - id = 0x%04lx len = 0x%lx, data=%02x%02x%02x%02x%02x%02x%02x%02x", msg_count + 1, RxHeader.StdId, RxHeader.DLC, RxData[0], RxData[1], RxData[2], RxData[3], RxData[4], RxData[5], RxData[6], RxData[7]);
}
msg_count++;
}
/* 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 */
I tried a lot of suggestions from this forum and also other examples.
On a WeAct Module with quartz also not more than this one pulse on the CANTX appear. Where is my fault, what am I not seeing here?
I would expect at least a frame until the ACK.
