基于單片機的CAN總線通信程序

//CAN <==> UART的協(xié)議轉(zhuǎn)換器
//
//程序名稱：CAN <---> UART協(xié)議轉(zhuǎn)換程序<透明方式>
//
//作者：王猛
//創(chuàng)建：2007-10-09
//
//說明：
//1，單片機使用P89C61X2BA
//--晶振11.0592MHZ
//--CAN總線中斷使用單片機的中斷0，外部有上拉電阻,波特率可以設(shè)定
//2，CAN總線發(fā)送采用查詢方式，接收采用中斷方式
//3，看門狗復位時間1.2S
//4，SJA1000晶振8MHZ,Peil模式
//5，串口中斷接收，查詢發(fā)送，波特率可設(shè)置
//6，×××當串口收到數(shù)據(jù)后，每8個數(shù)一組打包，通過CAN總線發(fā)送出去
//
//-----10.16日，重新修改程序完成以下功能-----
//----此功能已經(jīng)改為，每收到一幀數(shù)據(jù)，啟動一次CAN傳輸，傳輸字節(jié)數(shù)等于串口收到的數(shù)據(jù)
//----串行幀的幀間界定通過當前波特率下傳輸5個字節(jié)為時間間隔，具體為當順序接收到的任
//意兩個數(shù)據(jù)，它們之間的時間間隔大于5個字節(jié)傳送時間，認為這兩個數(shù)據(jù)分屬于兩個不
//同的幀
//
//7，當CAN總線每接收一幀信息后，通過串口發(fā)送出去
//-----10.15日，改為可以識別CAN的報文字節(jié)長度，即串口只發(fā)送CAN報文長度個字節(jié)
//8，看門狗芯片MAX1232CPA，硬件溢出時間1.2S
//
//-------------------------------------------------------

#include
#include
#include
#include "CANCOM.h"

//unsigned char UART_TX_Data[8] = {0,1,2,3,4,5,6,7};
//unsigned char CAN_TX_Data[8] = {0,1,2,3,4,5,6,7};
unsigned char xdata UART_RX_Data[255];//串口接收到的串行幀
unsigned char xdata CAN_TX_Data[255];//待發(fā)送的數(shù)據(jù)緩沖區(qū)
unsigned char code ACR_ID[4] = {0,0,0,0};//CAN初始設(shè)置驗收濾波值
unsigned char code AMR_ID[4] = {0xff,0xff,0xff,0xff};
unsigned char CAN_TX_ID[4] = {0,0,0,0};//待發(fā)送的目標的ID
unsigned char CAN_RX_ID[4] = {0,0,0,0};//接收到的信息來自何ID
unsigned char CAN_RX_Data[8] = {7,6,5,4,3,2,1,0};//接受到的數(shù)據(jù)緩沖
unsigned char code CAN_BTR0[10] = {0xdf,0xcf,0xc7,0xc3,0x43,0xc1,0xc1,0xc0,0xc0,0x80};
unsigned char code CAN_BTR1[10] = {0x7f,0x7f,0x7f,0x7f,0x2f,0x7f,0x4d,0x3e,0x3a,0x23};
//5K 10K 20K 40K 50K 80K 100K 200K 250K 500K
unsigned char code UART_BTR[4] = {0xe8,0xf4,0xfa};
// 1.2K,2.4K,4.8K

unsigned char CAN_flag;//CAN發(fā)送標志位
unsigned char UART_flag;//
unsigned char CAN_ERROR_flag = NOT;//
unsigned char CAN_DataLength = 8;//CAN信息的報文長度
unsigned char UART_DataLength = 0;//串口接收時的當前指示
unsigned char UART_Length = 0;//串口接收區(qū)的長度指示
//sbit AAA = P1^4;

void main(void)
{
EA = 0;
System_init();//系統(tǒng)初始化
Timer_init();//定時器初始化
Interrupt_init();//中斷
UART_ini();
CAN_init();
Delay(1);
W_WDT();
EA = 1;

//Delay(1);
//UART_Length = 8;
//CAN_Transmit(0);
//UART_Transmit();

while (1)
{
W_WDT();

if (CAN_flag == YES)
{
CAN_flag = NOT;
CAN_Transmit(0);
LED1 = !LED1;
}
else
{
CAN_flag = NOT;
}
/*
if (UART_flag == YES)
{
UART_flag = NOT;
//Delay(50);
UART_Transmit();
//Clear_Buffer(CAN_RX_Data,8);
//LED3 = !LED3;
}
else
{
UART_flag = NOT;
}

*/
if ((CAN_ERROR_flag == YES))
{
CAN_ERROR_flag = NOT;
CAN_init();
}
else
{
CAN_ERROR_flag = NOT;
}
}
}
//---------------------------
//功能：系統(tǒng)設(shè)置
//--外部數(shù)據(jù)存儲區(qū)訪問使能
//--LED指示燈關(guān)（1＝on，0＝off）
//--流程控制標志置為無效NOT
//--清空串口，CAN的相關(guān)數(shù)據(jù)緩沖區(qū)
//---------------------------
void System_init(void)
{
CKCON = 0x00;//Fosc devide 12
AUXR = 0x00;//0x02;//EXM enable
LED1 = 0;//LED0-3 off指示燈，共陰接法，1時亮
LED2 = 0;
LED3 = 0;
LED4 = 0;
WDT = 1;//WDT ini

CAN_DataLength = 8;
UART_DataLength = 0;
UART_Length = 0;

CAN_flag = NOT;
CAN_ERROR_flag = NOT;
//UART_flag = NOT;

Clear_Buffer(UART_RX_Data,255);
Clear_Buffer(CAN_TX_Data,255);
Clear_Buffer(CAN_TX_ID,4);
Clear_Buffer(CAN_RX_ID,4);
Clear_Buffer(CAN_RX_Data,8);

/*
CAN_flag = YES;
UART_flag = YES;
*/
}
//-----------------------------
//
//軟件延時（非精確）
//----內(nèi)置清看門狗定時器子函數(shù)
//防止多次調(diào)用延時過長導致
//看門狗復位
//
//-----------------------------
void Delay(unsigned char time)
{
unsigned char i;
unsigned int j;

for (i = 0;i < time;i++)
{
W_WDT();
for (j=0;j<30000;j++)
{
}
}
}

//---------------------------------
//串行口初始化設(shè)置
//方式1，8數(shù)據(jù)位，一個停止位，無奇偶校驗
//串口中斷允許
//------------------------------------
void UART_ini(void)
{
SCON = 0x50;//方式1，波特率可變，8bits，接受允許
PCON&= 0x7F;//SMOD = 0
TMOD |= 0x20;//timer1 mode 2

TL1 = UART_BTR[2];//|f
//|波特率＝----------------------
TH1 = UART_BTR[2];//|32*2^smod*12*(256-TL1)
TCON |= 0x40;//start

TI = 0;
}

//-----------------------------------------------
//
//看門狗“喂狗”程序，WDT的一個下降沿觸發(fā)一次
//
//-----------------------------------------------
void W_WDT(void)//triggle WDT
{
unsigned char i;
WDT = 1;
for (i=0;i<10;i++)
{
}
WDT = 0;
}

//---------------------------------------------------
//
//中斷初始化
//
//----外部中斷0有效，下降沿觸發(fā)，用于SJA1000產(chǎn)生CAN事件中斷
//----定時器中斷，用于判定串口接收的順序兩個字節(jié)是否分屬兩幀
//----串口中斷，RX使用中斷，TX未使用
//----中斷優(yōu)先級暫時未設(shè)定
//
//---------------------------------------------------
void Interrupt_init(void)
{
//IP = 0x00;
IT0 = 0x01; //外部0中斷沿觸發(fā)

ET0 = 1;//定時器0中斷使能
EX0 = 1;//外部中斷使能
ES = 1; //串行中斷使能
}

//---------------------------------------------------
//
//定時中斷程序
//
//一旦中斷，說明一幀的接收已經(jīng)結(jié)束，開始啟動CAN發(fā)送程序
//把串口接收到的數(shù)據(jù)準備好給CAN總線發(fā)送
//RX_buffer ===> CAN_TX_buffer
//
//---------------------------------------------------
void Timer0_ISR(void) interrupt 1 using 2
{
static unsigned char i;
//unsigned char counter;

//TH0 = temp_TH0;
//TL0 = temp_TL0;

/*counter += 1;
if (counter == 20)//到1S了么？
{
//UART_flag = YES;
}
if (counter == 40)//到2S了么？
{
//CAN_flag = YES;
counter = 0;
}*/
//AAA = !AAA;
TR0 = 0;//定時器關(guān),開始次CAN信息傳送

for (i=0;i<uart_datalength;i++)
{
CAN_TX_Data[i] = UART_RX_Data[i];
}
UART_Length = UART_DataLength;
UART_DataLength = 0;
CAN_flag = YES;
}
//---------------------------------------------------------------
//
//串口中斷服務(wù)程序
//
//----只有接收使用
//----每收一個數(shù)重新初始化定時器
//
//----------------------------------------------------------------
void RX_INT(void) interrupt 4 using 3
{
static unsigned char n;

if (RI==1)
{
do
{
RI = 0;
}
while (RI != 0);

//UART_RX_Data[UART_DataLength++] = SBUF;
n = SBUF;
UART_Send_Byte(n);

TH0 = temp_TH0;
TL0 = temp_TL0;
TR0 = 1;//啟動數(shù)據(jù)間隔定時，判斷是否分屬兩幀
}
else
{
//TX
}
}
//---------------------------------------------------------------
//
//串口發(fā)送單字節(jié)程序
//
//----------------------------------------------------------------
void UART_Send_Byte(unsigned char Data)
{
SBUF = Data;
while (TI == 0)//等待發(fā)送完畢
{
}
TI = 0;
}

//---------------------------------------------------------------
//
//初始化定時器程序
//
//----定時器0方式1，定時器1方式2留給串口
//
//----------------------------------------------------------------
void Timer_init(void)
{
TMOD |= 0x01;//使用定時器0－方式1

TH0 = temp_TH0;
TL0 = temp_TL0;
//TR0 = 1;//這里不打開定時器
}

void CAN_init(void)
{

EA = 0;
MOD_CAN1 |= 0x08;//單濾波方式
do
{
MOD_CAN1 |= 0x01; //request to reset mode
}
while ((MOD_CAN1&0x01) != 0x01);

CDR_CAN1 = 0xc8;//選擇PeliCAN模式，使用輸入比較器，clk_out關(guān)閉
IER_CAN1 = 0x01;//允許發(fā)送中斷，其他中斷禁能

ACR0_CAN1 = ACR_ID[0];
ACR1_CAN1 = ACR_ID[1];
ACR2_CAN1 = ACR_ID[2];
ACR3_CAN1 = ACR_ID[3];
AMR0_CAN1 = AMR_ID[0];
AMR1_CAN1 = AMR_ID[1];
AMR2_CAN1 = AMR_ID[2];
AMR3_CAN1 = AMR_ID[3];

//ECC_CAN1 = 0;
//TXERR_CAN1 = 0;
//RBSA_CAN1 = 0;

BTR0_CAN1 = CAN_BTR0[0];
BTR1_CAN1 = CAN_BTR1[0];
OCR_CAN1 = 0xaa;//normal output

W_WDT();
do
{
MOD_CAN1 &= 0xfe;
}
while ((MOD_CAN1&0x01) != 0x00);
EA = 1;
}

//-----------------------------------
//
//串口發(fā)送一幀接受到的CAN數(shù)據(jù)
//
//----長度1－8，根據(jù)接收到的CAN信息來確定
//
//-----------------------------------
void UART_Transmit(void) //using 0
{
unsigned char i;

LED3 = !LED3;
for (i=0;i{
UART_Send_Byte(CAN_RX_Data[i]);
}
}
//-----------------------------------
//
//CAN發(fā)送接受到的一幀串口數(shù)據(jù)
//
//----最大長度255，根據(jù)接收到的串口信息的
//個數(shù)來確定
//----按每依次8個數(shù)據(jù)作為一個CAN幀的報文部分
//不足8個或超過8的倍數(shù)的部分按實際個數(shù)作
//為CAN報文
//----FarmeType = 1為擴展幀，F(xiàn)armeType = 0為
//標準幀
//-----------------------------------
void CAN_Transmit(bit FarmeType)
{

unsigned char i;
unsigned char m;
unsigned char can_status;
unsigned char xdata *pointer;


if (FarmeType == 0)//標準幀
{
for (m=0;m<(UART_Length/8);m++)
{
W_WDT();
do//發(fā)送緩沖區(qū)空么？
{
can_status = SR_CAN1;
}
while ((can_status&0x04) != 0x04);

TXFrameInfo1 = 0x00 + 0x08;
pointer = &TXID1;
for (i=0;i<2;i++)
{
*(pointer++) = CAN_TX_ID[i];
}

pointer = &TXID3;
for (i=0;i<8;i++)
{
*(pointer++) = CAN_TX_Data[i+8*m];
}
CMR_CAN1 = Request_TX;
W_WDT();
}

if ((UART_Length%8) != 0)
{
W_WDT();
do //發(fā)送緩沖區(qū)空么？
{
can_status = SR_CAN1;
}
while ((can_status&0x04) != 0x04);
TXFrameInfo1 = 0x00 + UART_Length%8;
pointer = &TXID1;
for (i=0;i<2;i++)
{
*(pointer++) = CAN_TX_ID[i];
}

pointer = &TXID3;
for (i=0;i<(UART_Length%8);i++)
{
*(pointer++) = CAN_TX_Data[i+8*(UART_Length/8)];
}
CMR_CAN1 = Request_TX;
W_WDT();
}
else
{
}
}
else//擴展幀
{
for (m=0;m<(UART_Length/8);m++)
{
W_WDT();
do//發(fā)送緩沖區(qū)空么？
{
can_status = SR_CAN1;
}
while ((can_status&0x04) != 0x04);

TXFrameInfo1 = 0x80 + 0x08;
pointer = &TXID1;
for (i=0;i<4;i++)
{
*(pointer++) = CAN_TX_ID[i];
}

pointer = &TXDATA1;
for (i=0;i<8;i++)
{
*(pointer++) = CAN_TX_Data[i+8*m];
}
CMR_CAN1 = Request_TX;
W_WDT();
}

if ((UART_Length%8) != 0)
{
W_WDT();
do//發(fā)送緩沖區(qū)空么？
{
can_status = SR_CAN1;
}
while ((can_status&0x04) != 0x04);
TXFrameInfo1 = 0x80 + UART_Length%8;
pointer = &TXID1;
for (i=0;i<4;i++)
{
*(pointer++) = CAN_TX_ID[i];
}

pointer = &TXDATA1;
for (i=0;i<(UART_Length%8);i++)
{
*(pointer++) = CAN_TX_Data[i+8*(UART_Length/8)];
}
CMR_CAN1 = Request_TX;
W_WDT();
}
else
{
}
}

UART_Length = 0;

}

//-----------------------------------
//
//CAN接收中斷服務(wù)程序
//
//----判斷是否是RX中斷，如果是
//把接受到的CAN信息通過串行口發(fā)送出去
//----其他的中斷說明CAN總線出現(xiàn)錯誤或脫離
//
//-----------------------------------
void CAN_ISR(void) interrupt 0 using 1
{
unsigned char can_int;

EA = 0;

can_int = IR_CAN1;
if ((can_int&0x01) == 0x01)//接收中斷
{
CAN_Receive();
CMR_CAN1 |= ReleaseRXBuf;
}
else
{
CAN_ERROR_flag = YES;//其他中斷，暫時未用
}

//UART_flag = YES;
//CAN_flag = YES;
UART_Transmit();

EA = 1;
}

//-----------------------------------
//
//CAN接收數(shù)據(jù)函數(shù)
//
//----根據(jù)接受到的幀信息，按不同的長度存儲
//報文數(shù)據(jù)
//
//-----------------------------------
void CAN_Receive(void) using 1
{
unsigned char i;
unsigned char xdata *pointer;
unsigned char Info;

Info = RXFrameInfo1;

if ((Info&0x80) == 0)//standard Frame
{
//CAN_RX_ID[0] = RXID1;
//CAN_RX_ID[1] = RXID2;

CAN_DataLength = Info&0x0f;
pointer = &RXID3;
for (i=0;i{
CAN_RX_Data[i] = *(pointer++);
}
for (;i<8;i++)
{
CAN_RX_Data[i] = 0x00;
}
}
else//Ex Frame
{
//CAN_RX_ID[0] = RXID1;
//CAN_RX_ID[1] = RXID2;
//CAN_RX_ID[2] = RXID3;
//CAN_RX_ID[3] = RXID4;
CAN_DataLength = Info&0x0f;
pointer = &RXDATA1;
for (i=0;i{
CAN_RX_Data[i] = *(pointer++);
//pointer += 1;
}
for (;i<8;i++)
{
CAN_RX_Data[i] = 0x00;
}
}
}
//-----------------------------------
//
//清0緩沖區(qū)
//
//----pointer,指向待清0 的緩沖區(qū)首地址
//----length 清0 的長度
//-----------------------------------
void Clear_Buffer(unsigned char *pointer,unsigned char length)
{
unsigned char i;

for (i=0;i{
*(pointer++) = 0x00;
}
}

另外頭文件為：

#ifndef _CANCOM_H
#define _CANCOM_H

#define CS1_SJA1000 0x7f00//SJA1000 Pin /CS ----> P2.7,low level active

#define MOD_CAN1XBYTE[CS1_SJA1000+0] //Peli
#define CMR_CAN1XBYTE[CS1_SJA1000+1]//command
#define SR_CAN1XBYTE[CS1_SJA1000+2] //state
#define IR_CAN1XBYTE[CS1_SJA1000+3] //interrupt
#define IER_CAN1XBYTE[CS1_SJA1000+4]//interrupt enable //Peli
#define BTR0_CAN1XBYTE[CS1_SJA1000+6] //bus timing0
#define BTR1_CAN1XBYTE[CS1_SJA1000+7] //bus timing1
#define OCR_CAN1XBYTE[CS1_SJA1000+8]
#define TEST_CAN1XBYTE[CS1_SJA1000+9]
#define ECC_CAN1XBYTE[CS1_SJA1000+12]//error catch
#define EWLR_CAN1XBYTE[CS1_SJA1000+13]//error warning limit
#define RXERR_CAN1XBYTE[CS1_SJA1000+14]//
#define TXERR_CAN1XBYTE[CS1_SJA1000+15]
#define ACR0_CAN1XBYTE[CS1_SJA1000+16]
#define ACR1_CAN1XBYTE[CS1_SJA1000+17]
#define ACR2_CAN1XBYTE[CS1_SJA1000+18]
#define ACR3_CAN1XBYTE[CS1_SJA1000+19]
#define AMR0_CAN1XBYTE[CS1_SJA1000+20]
#define AMR1_CAN1XBYTE[CS1_SJA1000+21]
#define AMR2_CAN1XBYTE[CS1_SJA1000+22]
#define AMR3_CAN1XBYTE[CS1_SJA1000+23]
#define RBSA_CAN1XBYTE[CS1_SJA1000+30]//beginning of receive
#define CDR_CAN1XBYTE[CS1_SJA1000+31]//clock devide

#define TXFrameInfo1 XBYTE[CS1_SJA1000+16]
#define TXID1 XBYTE[CS1_SJA1000+17]
#define TXID2 XBYTE[CS1_SJA1000+18]
#define TXID3 XBYTE[CS1_SJA1000+19]
#define TXID4 XBYTE[CS1_SJA1000+20]
#define TXDATA1 XBYTE[CS1_SJA1000+21]
#define TXDATA2 XBYTE[CS1_SJA1000+22]
#define TXDATA3 XBYTE[CS1_SJA1000+23]
#define TXDATA4 XBYTE[CS1_SJA1000+24]
#define TXDATA5 XBYTE[CS1_SJA1000+25]
#define TXDATA6 XBYTE[CS1_SJA1000+26]
#define TXDATA7 XBYTE[CS1_SJA1000+27]
#define TXDATA8 XBYTE[CS1_SJA1000+28]

#define RXFrameInfo1 XBYTE[CS1_SJA1000+16]
#define RXID1 XBYTE[CS1_SJA1000+17]
#define RXID2 XBYTE[CS1_SJA1000+18]
#define RXID3 XBYTE[CS1_SJA1000+19]
#define RXID4 XBYTE[CS1_SJA1000+20]
#define RXDATA1 XBYTE[CS1_SJA1000+21]
#define RXDATA2 XBYTE[CS1_SJA1000+22]
#define RXDATA3 XBYTE[CS1_SJA1000+23]
#define RXDATA4 XBYTE[CS1_SJA1000+24]
#define RXDATA5 XBYTE[CS1_SJA1000+25]
#define RXDATA6 XBYTE[CS1_SJA1000+26]
#define RXDATA7 XBYTE[CS1_SJA1000+27]
#define RXDATA8 XBYTE[CS1_SJA1000+28]

#defineGoToRESET0x01
#defineReleaseRXBuf0x04
#defineRequest_TX0x01

#defineNOT0
#defineYES1
//4800bps 5bits 1.04mS
#define TIME_MS1
#define temp_TH0(0 - 922*TIME_MS)/256
#define temp_TL0(0 - 922*TIME_MS)%256

sbit LED1 = P1^2;
sbit LED2 = P1^3;
sbit LED3 = P1^5;
sbit LED4 = P1^4;
sbit WDT = P3^4;

void System_init(void);
void Delay(unsigned char time);
void W_WDT(void);
void Interrupt_init(void);
void CAN_init(void);
//void CAN_Transmit(unsigned char Farmeinfo);
void CAN_Transmit(bit FarmeType);
void CAN_Receive(void);
void Timer_init(void);
void UART_ini(void);
void UART_Send_Byte(unsigned char Data);
void UART_Transmit(void);
void Clear_Buffer(unsigned char *pointer,unsigned char length);

#endif