STM32F3—CAN通信自发自收

CAN通信是STM32中比较复杂的东西之一，它的初始化主要分为两个部分，一个是CAN的初始化，一个是过滤器的初始化。自发自收只需要一个器件，CAN的模式选择回环(Loopback)模式，这种模式下发出的数据也会被CAN本身接收回来，只需要检查接收到的数据和发送的数据是否一样，就能测试发送是否成功。

代码：

void CAN_Config(void)

{

CAN_InitTypeDef CAN_InitStructure;

CAN_FilterInitTypeDef CAN_FilterInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1,ENABLE);

CAN_DeInit(CAN1);

CAN_StructInit(&CAN_InitStructure);

CAN_InitStructure.CAN_TTCM = DISABLE;

CAN_InitStructure.CAN_ABOM = DISABLE;

CAN_InitStructure.CAN_AWUM = DISABLE;

CAN_InitStructure.CAN_NART = DISABLE;

CAN_InitStructure.CAN_RFLM = DISABLE;

CAN_InitStructure.CAN_TXFP = DISABLE;

CAN_InitStructure.CAN_Mode=CAN_Mode_LoopBack;//回环模式

CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;//1

CAN_InitStructure.CAN_BS1=CAN_BS1_9tq;//9

CAN_InitStructure.CAN_BS2=CAN_BS2_8tq;//8

CAN_InitStructure.CAN_Prescaler=16;//16分频

CAN_Init(CAN1,&CAN_InitStructure);

CAN_FilterInitStructure.CAN_FilterNumber=0;

CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;//屏蔽模式

CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;

CAN_FilterInitStructure.CAN_FilterIdHigh = 0x0000;

CAN_FilterInitStructure.CAN_FilterIdLow = 0x0000;

CAN_FilterInitStructure.CAN_FilterMaskIdHigh = 0x0000;

CAN_FilterInitStructure.CAN_FilterMaskIdLow = 0x0000;

CAN_FilterInitStructure.CAN_FilterFIFOAssignment = CAN_FilterFIFO0;

CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;

CAN_FilterInit(&CAN_FilterInitStructure);

}

配置完成，开始发送和接收：

void CAN_Test(void)

{

CanTxMsg TXmessage;

CanRxMsg RXmessage;

uint8_t TxMailbox=0;

uint8_t ret=0;

CAN_Config();

TXmessage.StdId=0x123;//ID,标识符

TXmessage.IDE=CAN_ID_STD;//标准ID

TXmessage.RTR=CAN_RTR_DATA;//传送的是数据帧

TXmessage.DLC=3;//数据个数。不能超过8个

TXmessage.Data[0]=0x01;//传送的数据

TXmessage.Data[1]=0x10;

TXmessage.Data[2]=0xFF;

TxMailbox=CAN_Transmit(CAN1,&TXmessage);//发送，返回的是当前邮箱号

while(CAN_TransmitStatus(CAN1,TxMailbox) !=CANTXOK);//等待发送完成

while(CAN_MessagePending(CAN1,CAN_FIFO0)<1);//查询接受状态位，看是否有信息(报文)到达

RXmessage.StdId=0x00;//初始化接受结构体

RXmessage.IDE=CAN_ID_STD;

RXmessage.DLC=0;

RXmessage.Data[0]=0;

RXmessage.Data[1]=0;

RXmessage.Data[2]=0;

CAN_Receive(CAN1,CAN_FIFO0,&RXmessage);//接收信息(报文)

//最后检查所接收到的数据每一个项和发送的是否一样，如果全部一样则发送成功，否则发送失败

//设置标志位对结果进行保存，用串口打印或者LED显示不同的状态来表示发送接收情况

}