重学STM32---（十） ——CAN通信(二)

#include "can.h"
//#include "stm32f10x.h"
#include "sys.h"


#define CAN_INT_ENABLE    0


void CAN_Init(u8 sjw, u8 ts2, u8 ts1,u16 brp, u8 mode)
{
    sjw -= 1;
    ts1 -= 1;
    ts2 -= 1;
    brp -= 1;
    
    /*开启CAN_TX与CAN_RX的时钟PB*/
    RCC->APB2ENR |= 1 << 3;                                               
    /*开启CAN时钟*/
    RCC->APB1ENR |= 1 << 25;

    /*设置PB11上拉输入，PB12推挽输出*/
    GPIOB->CRH &= ~(0xff << 12);
    GPIOB->CRH |= 0xB3 << 12;
    GPIOB->ODR |= 1<<11;
    
    /*对CAN初始化*/
    CAN1->MCR |= 1 << 15;          //软复位 
    CAN1->MCR &= ~(1 << 1);
    CAN1->MCR |= 1 << 0;           //设置初始化模式
    while(!(CAN1->MSR & 1 << 0));   //等待确认初始化
    
    CAN1->MCR |= 0 << 7;           //禁止时间触发模式
    CAN1->MCR |= 0 << 6;           //禁止自动离线
    CAN1->MCR |= 0 << 5;            //禁止自动唤醒
    CAN1->MCR |= 1 << 4;            //报文只传送一次，禁止自动重传
    CAN1->MCR |= 0 << 2;            //优先级由报文的标识符决定
    /* 设置CAN位时序*/
    CAN1->BTR &= 0x00000000;        //
    CAN1->BTR |= mode << 30;        //正常模式或环回模式
    CAN1->BTR |= sjw << 24;            //设置sjw
    CAN1->BTR |= ts2 << 20;            //
    CAN1->BTR |= ts1 << 16;            //
    CAN1->BTR |= brp << 0;

    CAN1->MCR &= ~(1 << 0);            //退出初始化
    while(CAN1->MSR & 1 << 0);        //确认退出初始化
    
    /* 设置过滤器组 */
    
    CAN1->FMR |= 1 << 0;            //过滤器组设置在初始化模式
    CAN1->FA1R &= ~(1 << 0);        //过滤器禁用
    CAN1->FM1R &= ~(1<< 0);   //过滤器组工作在标识符屏蔽位模式
    CAN1->FS1R |= 1<<0;         //过滤器组位宽为32位
    CAN1->FFA1R &= ~(1 << 0);  //关联到fifo0
    CAN1->sFilterRegister[0].FR1 = 0X00000000;     //全都为0 ，什么数据都接受
    CAN1->sFilterRegister[0].FR2 = 0X00000000;
    CAN1->FA1R |= 1 << 0;        //激活过滤器
    CAN1->FMR &= 0 << 0;         //退出滤波器初始化模式
    
#if CAN_INT_ENABLE
    CAN1->IER |= 1 << 1;   //FIFO0消息挂号中断使能
    MY_NVIC_Init(2,2,USB_LP_CAN1_RX0_IRQn,2);
#endif

}



ide 0：标准帧  1：扩展帧
id  标识id
rtr  0：数据帧  1：远程帧
len 数据长度
*data 指向要发送数据的指针
u8 CAN_TX_Msg(u8 ide, u32 id, u8 rtr, u8 len, u8 *data)
{
    u8 mbox;
    if(CAN1->TSR & 1<<26) mbox = 0;   //邮箱0为空
    if(CAN1->TSR & 1<<27) mbox = 1;
    if(CAN1->TSR & 1<<28) mbox = 2;
    else return 0xff;
    
    /*为标准id时*/
    if(ide == 0)
    {
        id = id & 0x07ff;          //取11位
        id <<= 21;
    }
    /*为扩展ID时*/
    if(ide == 1)
    {
        id <<= 3;
    }
    CAN1->sTxMailBox[mbox].TIR = 0;
    CAN1->sTxMailBox[mbox].TIR |= ide << 2;        //  
    CAN1->sTxMailBox[mbox].TIR |= id ;             //
    CAN1->sTxMailBox[mbox].TIR &= ~(1<<1);         //
    CAN1->sTxMailBox[mbox].TDTR |= len&0xf;        //
    
    CAN1->sTxMailBox[mbox].TDLR =((u32)data[0]) | ((u32)data[1]<<8) | ((u32)data[2]<<16) | ((u32)data[3]<<24);
    CAN1->sTxMailBox[mbox].TDHR =((u32)data[4]) | ((u32)data[5]<<8) | ((u32)data[6]<<16) | ((u32)data[7]<<24);
    
    CAN1->sTxMailBox[mbox].TIR |= 1 << 0;
    return     mbox ;
}
 

//判断发送是成功
//state = 7成功
u8 CAN_TX_Statt(u8 mbox)
{
    u8 state;
    switch(mbox)
    {
        case 0:
            state |= (CAN1->TSR & 1<<0) | (CAN1->TSR & 1<<1) |((CAN1->TSR & 1<<26)>>24);
            break ;
        case 1:
            state |= (CAN1->TSR & 1<<8)>>8;
            state |= (CAN1->TSR & 1<<9)>>9;
            state |= (CAN1->TSR & 1<<27)>>25;
            break ;
        case 2:
            state |= (CAN1->TSR & 1<<16)>>16;
            state |= (CAN1->TSR & 1<<17)>>17;
            state |= (CAN1->TSR & 1<<28)>>26;
            break ;
        default :
            state = 0x05;
    }
    return state ;

}

//得到在FIFO0/FIFO1中接收到的报文个数.
//fifox:0/1.FIFO编号;
//返回值:FIFO0/FIFO1中的报文个数.
u8 CAN_Msg_Pend(u8 fifox)
{
    if(fifox==0)return CAN1->RF0R&0x03; 
    else if(fifox==1)return CAN1->RF1R&0x03; 
    else return 0;
}


参数同上
void CAN_RX_Msg(u8 *ide, u32* id, u8* rtr, u8* len, u8 *data, u8 fifox)
{
    *ide = (CAN1->sFIFOMailBox[fifox].RIR & 1<<2)>>2;
    if(*ide == 0)
    {
        *id = CAN1->sFIFOMailBox[fifox].RIR >> 21;
    }
    else 
    {
        *id = CAN1->sFIFOMailBox[fifox].RIR >> 3;
    }
    *rtr = (CAN1->sFIFOMailBox[fifox].RIR & 1<<1)>>1;
    
    *len = CAN1->sFIFOMailBox[fifox].RDTR & 0x0f;
    
        //接收数据
    data[0]=CAN1->sFIFOMailBox[fifox].RDLR&0XFF;
    data[1]=(CAN1->sFIFOMailBox[fifox].RDLR>>8)&0XFF;
    data[2]=(CAN1->sFIFOMailBox[fifox].RDLR>>16)&0XFF;
    data[3]=(CAN1->sFIFOMailBox[fifox].RDLR>>24)&0XFF;    
    data[4]=CAN1->sFIFOMailBox[fifox].RDHR&0XFF;
    data[5]=(CAN1->sFIFOMailBox[fifox].RDHR>>8)&0XFF;
    data[6]=(CAN1->sFIFOMailBox[fifox].RDHR>>16)&0XFF;
    data[7]=(CAN1->sFIFOMailBox[fifox].RDHR>>24)&0XFF;    
      if(fifox==0)CAN1->RF0R|=0X20;//释放FIFO0邮箱
    else if(fifox==1)CAN1->RF1R|=0X20;//释放FIFO1邮箱     

}



//
u8 CAN_Send_Msg(u8* data, u8 len)
{
    u8 mbox;
    u16 i = 0;
    mbox = CAN_TX_Msg(0,0X12,0,len,data);
    while((CAN_TX_Statt(mbox) != 7) && (i < 0xfff)) i++;
    return 0;
}


//返回0 接收失败
u8 CAN_Receive_Msg(u8* data)
{
    u32 id;
    u8 ide = 0,rtr = 0,len = 0;
    while(!CAN_Msg_Pend(0));
    CAN_RX_Msg(&ide,&id,&rtr,&len,data,0);
    if( id!=0x12 || ide!=0 || rtr!=0) return 0;
    else return len;
}