stm32 can总线参考例程

//CAN初始化 //tsjw:重新同步跳跃时间单元.范围:1~3; CAN_SJW_1tq CAN_SJW_2tq CAN_SJW_3tq CAN_SJW_4tq //tbs2:时间段2的时间单元.范围:1~8; //tbs1:时间段1的时间单元.范围:1~16; CAN_BS1_1tq ~CAN_BS1_16tq //brp :波特率分频器.范围:1~1024;(实际要加1,也就是1~1024) tq=(brp)*tpclk1 //注意以上参数任何一个都不能设为0,否则会乱. //波特率=Fpclk1/((tsjw+tbs1+tbs2)*brp); //mode:0,普通模式;1,回环模式; //Fpclk1的时钟在初始化的时候设置为36M,如果设置CAN_Normal_Init(1,8,7,5,1); //则波特率为:36M/((1+8+7)*5)=450Kbps //返回值:0,初始化OK; // 其他,初始化失败; u8 CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode) { GPIO_InitTypeDef GPIO_InitStructure; CAN_InitTypeDef CAN_InitStructure; CAN_FilterInitTypeDef CAN_FilterInitStructure; #if CAN_RX0_INT_ENABLE NVIC_InitTypeDef NVIC_InitStructure; #endif RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//使能PORTA时钟 RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);//使能CAN1时钟 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽 GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化IO GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉输入 GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化IO //CAN单元设置 CAN_InitStructure.CAN_TTCM=DISABLE; //非时间触发通信模式 // CAN_InitStructure.CAN_ABOM=DISABLE; //软件自动离线管理 // CAN_InitStructure.CAN_AWUM=DISABLE; //睡眠模式通过软件唤醒(清除CAN->MCR的SLEEP位)// CAN_InitStructure.CAN_NART=ENABLE; //禁止报文自动传送 // CAN_InitStructure.CAN_RFLM=DISABLE; //报文不锁定,新的覆盖旧的 // CAN_InitStructure.CAN_TXFP=DISABLE; //优先级由报文标识符决定 // CAN_InitStructure.CAN_Mode= mode; //模式设置： mode:0,普通模式;1,回环模式; // //设置波特率 CAN_InitStructure.CAN_SJW=tsjw; //重新同步跳跃宽度(Tsjw)为tsjw+1个时间单位 CAN_SJW_1tq CAN_SJW_2tq CAN_SJW_3tq CAN_SJW_4tq CAN_InitStructure.CAN_BS1=tbs1; //Tbs1=tbs1+1个时间单位CAN_BS1_1tq ~CAN_BS1_16tq CAN_InitStructure.CAN_BS2=tbs2;//Tbs2=tbs2+1个时间单位CAN_BS2_1tq ~ CAN_BS2_8tq CAN_InitStructure.CAN_Prescaler=brp; //分频系数(Fdiv)为brp+1 // CAN_Init(CAN1, &CAN_InitStructure); // 初始化CAN1 CAN_FilterInitStructure.CAN_FilterNumber=0; //过滤器0 CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask; CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; //32位 CAN_FilterInitStructure.CAN_FilterIdHigh=0x0000;32位ID CAN_FilterInitStructure.CAN_FilterIdLow=0x0000; CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;//32位MASK CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000; CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0;//过滤器0关联到FIFO0 CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; //激活过滤器0 CAN_FilterInit(&CAN_FilterInitStructure);//滤波器初始化 #if CAN_RX0_INT_ENABLE CAN_ITConfig(CAN1,CAN_IT_FMP0,ENABLE);//FIFO0消息挂号中断允许. NVIC_InitStructure.NVIC_IRQChannel = USB_LP_CAN1_RX0_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; // 主优先级为1 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; // 次优先级为0 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); #endif return 0; } #if CAN_RX0_INT_ENABLE //使能RX0中断 //中断服务函数 void USB_LP_CAN1_RX0_IRQHandler(void) { CanRxMsg RxMessage; int i=0; CAN_Receive(CAN1, 0, &RxMessage); for(i=0;i<8;i++) printf("rxbuf[%d]:%d\r\n",i,RxMessage.Data[i]); } #endif //can发送一组数据(固定格式:ID为0X12,标准帧,数据帧) //len:数据长度(最大为8) //msg:数据指针,最大为8个字节. //返回值:0,成功; // 其他,失败; u8 Can_Send_Msg(u8* msg,u8 len) { u8 mbox; u16 i=0; CanTxMsg TxMessage; TxMessage.StdId=0x12; // 标准标识符 TxMessage.ExtId=0x12; // 设置扩展标示符 TxMessage.IDE=CAN_Id_Standard; // 标准帧 TxMessage.RTR=CAN_RTR_Data; // 数据帧 TxMessage.DLC=len; // 要发送的数据长度 for(i=0;i<len;i++) TxMessage.Data[i]=msg[i]; mbox= CAN_Transmit(CAN1, &TxMessage); i=0; while((CAN_TransmitStatus(CAN1, mbox)==CAN_TxStatus_Failed)&&(i<0XFFF))i++; //等待发送结束 if(i>=0XFFF)return 1; return 0; } //can口接收数据查询 //buf:数据缓存区; //返回值:0,无数据被收到; // 其他,接收的数据长度; u8 Can_Receive_Msg(u8 *buf) { u32 i; CanRxMsg RxMessage; if( CAN_MessagePending(CAN1,CAN_FIFO0)==0)return 0; //没有接收到数据,直接退出 CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);//读取数据 for(i=0;i<8;i++) buf[i]=RxMessage.Data[i]; return RxMessage.DLC; }