pic18f2480.c

pic18f2480的can模块初始化函数以及基本的收发操作

/**********************initcan***************************************/
void initcan(char CAN_ADRESS_H, char CAN_ADRESS_L)
{
/**********config the model of CAN********************************************/	
	trisb = (trisb | 0x08) & 0xfb;//config the rb3 for receive config the rb2 for send
	ecancon = 0x00;//config the legacy mode
	cancon= 0x80;//turn to config mode
	while((canstat&0x80)==0)//wait turn to the config mode success state
	{
		nop();
	}
	write_dbc(0,0,"config mode！");
/******************config the baud rate 80k*****************************************/	
	brgcon1 = 0x09;// config the SJW=1TQ, BRP=0x09
	brgcon2 = 0X98;//config the Phase_Seg1 = 4TQ, Prog_Seg = 1TQ
	brgcon3 = 0x83;//config the Phase_Seg2 = 4TQ
	//在这里需要注意到的是18F2480的指令周期是没有4分频的
/*********************
	the time = TQ*(Sync_Seg + Prop_Seg + Phase_seg1 + Phae_seg2)
	it must greater or equeal to 8TQ, 
	TQ = (2 * (BRP +1))/Fosc(Mhz)
************************************/
/************config the send mailbox and init the data for send********************/	
	txb0con = 0x03;//config the send priority for highest
	txb0sidl = CAN_ADRESS_L & 0xe0;//config the three low bit of adress the CAN_ADRESS_L is define by macro
	txb0sidh = CAN_ADRESS_H;//config the high eight bit of adreess the CAN_ADRESS_H is defined by marco
	txb0dlc = 0x08;//config the send code is 8 byte
	txb0d0 = 0xf0;//config the buff of sender
	txb0d1 = 0xf1;
	txb0d2 = 0xf2;
	txb0d3 = 0xf3;
	txb0d4 = 0xf4;
	txb0d5 = 0xf5;
	txb0d6 = 0xf6;
	txb0d7 = 0xf7;
/*************config the recever mailbox and init the data of receibe buffer**************************************************************/
	rxb0sidl = CAN_ADRESS_L & 0xe0;
	rxb0sidh = CAN_ADRESS_H;
	rxb0con = 0x20;//only receive the corresponding ID filhit0=0 means thar the rxb0 use the filer0
	rxb0dlc = 0x08;//config the length of the data
	rxb0d0 = 0x00;
	rxb0d1 = 0x01;
	rxb0d2 = 0x02;
	rxb0d3 = 0x03;
	rxb0d4 = 0x04;
	rxb0d5 = 0x05;
	rxb0d6 = 0x06;
	rxb0d7 = 0x07;
/*******init the filter 0 and mask*******************************************/	
	rxf0sidh = CAN_ADRESS_H;
	rxf0sidl = CAN_ADRESS_L;
	rxm0sidh = 0xff;
	rxm0sidl = 0xe0;
/**********config the work mode of the CAN****************************************/	
	cancon = 0x40;//when the bit6==1,it will be in the test mode,when be 0 is in normal mode
	while((canstat & 0x40) == 0)//wait for turn to loopback mode
	{
		nop();
	}
	write_dbc(1,0,"work mode！");
/*****turn to normal mode*******************************************/	
	cancon = 0x00;
	while(canstat != 0x00)
	{
		nop();
	}
	write_dbc(2,0,"normal mode！");
/************init the interrupt of CAN*****************************************/
	pie3 = pie3 | 0x01;
	ipr3 = ipr3 | 0x01;//config the interrupt to high priority
	pir3 = 0x00;
}

void send_msg(char *msg)
{
	txb0d0 = msg[0];//config the buff of sender
	txb0d1 = msg[1];
	txb0d2 = msg[2];
	txb0d3 = msg[3];
	txb0d4 = msg[4];
	txb0d5 = msg[5];
	txb0d6 = msg[6];
	txb0d7 = msg[7];
	txb0con = txb0con | 0x08;
	while((txb0con & 0x08) == 0)
	{
		nop();
	}
	write_dbc(3,7," M");
	//delay_s(4);
}
void interrupt(void)
{
	if(pir3.RXB0IF)
	{
		receive_flag = 1;
		if(can_point <= &can_buff[48])//防止接收溢出缓冲区
		{
			*(can_point++) = rxb0d0;
			*(can_point++) = rxb0d1;
			*(can_point++) = rxb0d2;
			*(can_point++) = rxb0d3;
			*(can_point++) = rxb0d4;
			*(can_point++) = rxb0d5;
			*(can_point++) = rxb0d6;
			*(can_point++) = rxb0d7;
			rxb0con.RXFUL = 0;//清除接收BUFF满标志使接收BUFFER能够再次接收信息
		}
		pir3.RXB0IF = 0;
	}
}
void main()
{
    int ID;
    char ID1,ID2;
    ID1 = ID >> 3;//CAN_H
    ID2 = ID << 5;//CAN_L
	
    initcan(i,tmp);
    

}