STM32CUBEMX配置圖
1.配置CAN引腳。
2.配置MCU時鐘
3.配置CAN外設相關的參數、波特率、工作模式等。
CAN波特率的計算
1.因為CAN的時鐘是AHB1外設時鐘,這裡為8MHZ。
2.根據圖上的設定,CAN波特率=8M/Prescaler/(Bit Segment 1+Bit Segment 2+Jump Width) Fcan=8/(8+7+1)=500K
3.這裡我們用預設的Normal模式。
4.打開CAN中斷
5.生成代碼之後修改一下代碼,代碼如下:
CAN_FilterConfTypeDef sFilterConfig;
static CanTxMsgTypeDef TxMassage;
static CanRxMsgTypeDef RxMassage;
main()
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_CAN_Init();
MX_NVIC_Init();
hcan.pTxMsg=&TxMassage;
hcan.pRxMsg=&RxMassage;
Configure_Filter();
HAL_CAN_Receive_IT(&hcan, CAN_FIFO0);
hcan.pTxMsg->StdId=0x123;
hcan.pTxMsg->ExtId=0x123;
hcan.pTxMsg->RTR=CAN_RTR_DATA;
hcan.pTxMsg->IDE=CAN_ID_STD;
hcan.pTxMsg->DLC=8;
hcan.pTxMsg->Data[0] = 1;
hcan.pTxMsg->Data[1] = 2;
hcan.pTxMsg->Data[2] = 3;
hcan.pTxMsg->Data[3] = 4;
hcan.pTxMsg->Data[4] = 5;
hcan.pTxMsg->Data[5] = 6;
hcan.pTxMsg->Data[6] = 7;
hcan.pTxMsg->Data[7] = 8;
if(HAL_CAN_Transmit(&hcan, 10) != HAL_OK)//測試一下是否能正常發送。
{
/* Transmition Error */
//Error_Handler();
}
while (1)
{
if(Flag_CANRxOver==1)
{
Flag_CANRxOver=0;
hcan.pTxMsg->StdId = hcan.pRxMsg->StdId;
hcan.pTxMsg->Data[0] = hcan.pRxMsg->Data[0];
hcan.pTxMsg->Data[1] = hcan.pRxMsg->Data[1];
hcan.pTxMsg->Data[2] = hcan.pRxMsg->Data[2];
hcan.pTxMsg->Data[3] = hcan.pRxMsg->Data[3];
hcan.pTxMsg->Data[4] = hcan.pRxMsg->Data[4];
hcan.pTxMsg->Data[5] = hcan.pRxMsg->Data[5];
hcan.pTxMsg->Data[6] = hcan.pRxMsg->Data[6];
hcan.pTxMsg->Data[7] = hcan.pRxMsg->Data[7];
if(HAL_CAN_Transmit(&hcan, 10) != HAL_OK)//發送剛剛接收到的CAN資料
{
/* Transmition Error */
//Error_Handler();
}
}
}
}
void HAL_CAN_RxCpltCallback(CAN_HandleTypeDef* hcan)
{
HAL_CAN_Receive_IT(hcan, CAN_FIFO0);
Flag_CANRxOver=1;
}
void Configure_Filter(void)
{
sFilterConfig.FilterNumber = 0; //過濾器組0
sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK; //辨別符屏蔽位模式
sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT;//濾波器位寬為單個32位
sFilterConfig.FilterIdHigh =(((unsigned int)0x0000<<3)&0xFFFF0000)>>16; //要過濾的ID高位,因為這個代碼設定不是過濾ID的,是以随意填了一個ID
sFilterConfig.FilterIdLow = (((unsigned int)0x0000<<3)|CAN_ID_STD|CAN_RTR_DATA)&0xFFFF;//要過濾的ID低位
//sFilterConfig.FilterMaskIdHigh = 0xffff;
//sFilterConfig.FilterMaskIdLow = 0xffff; //1表示來自發送端的ID與接收端FilterId比對才接收資料
sFilterConfig.FilterMaskIdHigh = 0; //這裡設定接收任意ID的CAN資料
sFilterConfig.FilterMaskIdLow = 0; //0表示接收來自發送端任意ID的資料
sFilterConfig.FilterFIFOAssignment =CAN_FILTER_FIFO0;//過濾器指向FIFO0;
sFilterConfig.FilterActivation = ENABLE;//使能過濾器
//sFilterConfig.BankNumber = 14;
HAL_CAN_ConfigFilter(&hcan, &sFilterConfig);
}