代码如下:
- #include "mycan.h"
- //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:48M/((1+8+7)*5)=450Kbps
- void CAN_Mode_Init(uint8_t tsjw,uint8_t tbs2,uint8_t tbs1,uint16_t brp,uint8_t 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_SYSCFG, ENABLE);
- RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);//使能PORTA时钟
- SYSCFG->CFGR1 |= SYSCFG_CFGR1_PA11_PA12_RMP; //RMAP
- GPIO_PinAFConfig(GPIOA,GPIO_PinSource12,GPIO_AF_4);
- GPIO_PinAFConfig(GPIOA,GPIO_PinSource11,GPIO_AF_4);
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN, ENABLE);//使能CAN时钟
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11|GPIO_Pin_12;
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
- GPIO_Init(GPIOA, &GPIO_InitStructure);
-
- CAN_DeInit(CAN);
- //CAN单元设置
- CAN_InitStructure.CAN_TTCM=DISABLE; //非时间触发通信模式 //
- CAN_InitStructure.CAN_ABOM=ENABLE; //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(CAN, &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
- }
- #if CAN_RX0_INT_ENABLE //使能RX0中断
- //中断服务函数
- void CEC_CAN_IRQHandler(void)
- {
- CanRxMsg RxMessage;
- int i=0;
- CAN_Receive(CAN, 0, &RxMessage);
- //for(i=0;i<8;i++)
- //printf("rxbuf[%d]:%d\r\n",i,RxMessage.Data<i>);</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;
- uint8_t Can_Send_Msg(uint8_t* msg,uint8_t len)
- {
- uint8_t mbox;
- uint16_t i=0;
- CanTxMsg TxMessage;
- TxMessage.StdId=0x12; // 标准标识符为0
- TxMessage.ExtId=0x12; // 设置扩展标示符(29位)
- TxMessage.IDE=0; // 使用扩展标识符
- TxMessage.RTR=0; // 消息类型为数据帧,一帧8位
- TxMessage.DLC=len; // 发送两帧信息
- for(i=0;i<len;i++)
- TxMessage.Data=msg; // 第一帧信息
- mbox= CAN_Transmit(CAN, &TxMessage);
- i=0;
- while((CAN_TransmitStatus(CAN, 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;
- uint8_t Can_Receive_Msg(uint8_t *buf)
- {
- uint32_t i;
- CanRxMsg RxMessage;
- if( CAN_MessagePending(CAN,CAN_FIFO0)==0)return 0; //没有接收到数据,直接退出
- CAN_Receive(CAN, CAN_FIFO0, &RxMessage);//读取数据
- for(i=0;i<8;i++)
- buf=RxMessage.Data;
- return RxMessage.DLC;
- }
复制代码
注意:一定要根据自己的封装来设置
SYSCFG->CFGR1 |= SYSCFG_CFGR1_PA11_PA12_RMP;
如果不设置 CAN_Init(CAN, &CAN_InitStructure);会初始化失败
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