【BIGTREETECH PI开发板】 CAN收发测试

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【BIGTREETECH PI开发板】 CAN收发测试 [复制链接]

 

测试下使用BIGTREETECH PI开发板测试CAN模块收发通信测试。

 

一、硬件连接

开发板连接CAN模块使用了下面接口

硬件连接图

 

二、程序代码

 

mcp2515.c

#include <stdio.h>
#include <wiringPi.h>
#include <mcp2515.h>
#include <unistd.h>
#include <stdint.h>

#define  SCK        0 //PC3
#define  SI         1 //pc0
#define  SO         2 //PC7
#define  CAN_CS     5 //PC14
#define  CAN_RST    7 //PC12
#define  CAN_INT    8 //PC10 


uint8_t can_tx_flag=0;
uint8_t can_rx_flag=0;

uint8_t spi_read(void)
{
	uint8_t n=8;
	uint8_t tdata=0;
    digitalWrite (SCK, LOW) ;
	while(n--)
	{
        usleep(1);
        digitalWrite (SCK, HIGH) ;
        usleep(1);
		tdata=(tdata<<1);
        if(digitalRead(SO)==HIGH)
			tdata=tdata|0x01;
		else 
			tdata=tdata&0xfe;
        digitalWrite (SCK, LOW) ;
	}	
	return tdata;
}

void spi_write(uint8_t ch)
{
	int n=8; 
    digitalWrite (SCK, LOW) ;
	while(n--)
	{
        digitalWrite (SCK, LOW) ;
		if((ch&0x80)==0x80) 
		{
            digitalWrite (SI, HIGH) ;
		}
		else
		{
            digitalWrite (SI, LOW) ;
		}
        digitalWrite (SCK, HIGH) ;

		ch=ch<<1;
	}
}

void mcp2515_reset(void)
{
    digitalWrite (CAN_RST, LOW) ;
    spi_write(CAN_RESET);
    digitalWrite (CAN_RST, HIGH) ;
}

void mcp2515_bitmodity(uint8_t addr, uint8_t msk, uint8_t dat)
{
    digitalWrite (CAN_CS, LOW);
    spi_write(CAN_BIT_MODIFY);      
    spi_write(addr);                                                         
    spi_write(msk);                                                                 
    spi_write(dat); 
    digitalWrite (CAN_CS, HIGH);                                                        
}


void spi_writebyte(uint8_t adr, uint8_t dat)
{
    digitalWrite (CAN_CS, LOW) ;
    spi_write(CAN_WRITE);
    spi_write(adr);
    spi_write(dat);
    digitalWrite (CAN_CS, HIGH) ;
}


int spi_readbyte(uint8_t adr)
{
    int rxdat;
    digitalWrite (CAN_CS, LOW);
    spi_write(CAN_READ);      
    spi_write(adr);              
    rxdat=spi_read();
    digitalWrite (CAN_CS, HIGH);    
    return rxdat;
}


void can_recrxb(uint8_t *CAN_RX_Buf)
{
    CAN_RX_Buf[0]=spi_readbyte(RXB0D0);                 
    CAN_RX_Buf[1]=spi_readbyte(RXB0D1);                 
    CAN_RX_Buf[2]=spi_readbyte(RXB0D2);
    CAN_RX_Buf[3]=spi_readbyte(RXB0D3);
    CAN_RX_Buf[4]=spi_readbyte(RXB0D4);
    CAN_RX_Buf[5]=spi_readbyte(RXB0D5);
    CAN_RX_Buf[6]=spi_readbyte(RXB0D6);
    CAN_RX_Buf[7]=spi_readbyte(RXB0D7);        
    spi_writebyte(CANINTF,0);                                                         
}

void can_send(uint8_t *CAN_TX_Buf)
{
    mcp2515_bitmodity(TXB0CTRL,0x08,0x00);   
    spi_writebyte(TXB0SIDH,0x55); 
    spi_writebyte(TXB0SIDL,0x08); 
    spi_writebyte(TXB0EID8,0x55); 
    spi_writebyte(TXB0EID0,0x88);
    spi_writebyte(TXB0DLC,DLC_8);         
    spi_writebyte(TXB0D0,CAN_TX_Buf[0]);          
    spi_writebyte(TXB0D1,CAN_TX_Buf[1]);
    spi_writebyte(TXB0D2,CAN_TX_Buf[2]);
    spi_writebyte(TXB0D3,CAN_TX_Buf[3]);
    spi_writebyte(TXB0D4,CAN_TX_Buf[4]);
    spi_writebyte(TXB0D5,CAN_TX_Buf[5]);
    spi_writebyte(TXB0D6,CAN_TX_Buf[6]);
    spi_writebyte(TXB0D7,CAN_TX_Buf[7]);
    digitalWrite (CAN_CS, LOW);
    spi_write(CAN_RTS | 0x01);                
    digitalWrite (CAN_CS, HIGH);
}


uint8_t can_readintf(void)
{
	uint8_t intf=0;
	intf=spi_readbyte(CANINTF);	 
	return intf;	
}
void can_setintf(uint8_t cmd)
{
	spi_writebyte(CANINTF,cmd);		
}

uint8_t rxbuf[8];
void mcp2515_isr(void)
{
    
    uint8_t rx_sta=0;
    can_tx_flag=1;

    rx_sta=can_readintf();
    if(rx_sta&0x01)
    {
        can_recrxb(rxbuf);
        can_setintf(0x00);
        can_rx_flag=1;
    }
    else
    {
        can_setintf(0x00);
    } 
    can_tx_flag=0;  
}

void init_mcp2515(void)
{
    pinMode(SCK, OUTPUT);
    pinMode(SI, OUTPUT);
    pinMode(SO, INPUT);
    pinMode(CAN_CS, OUTPUT);
    pinMode(CAN_RST, OUTPUT);
    pinMode(CAN_INT, INPUT);
    pullUpDnControl (CAN_INT, PUD_UP);

    wiringPiISR(CAN_INT,INT_EDGE_FALLING,&mcp2515_isr);

    mcp2515_reset();
    delay(2);

    mcp2515_bitmodity(CANCTRL,0xE0,0x80);
    spi_writebyte(CNF1,0x04);         //100k
    spi_writebyte(CNF2,0x80|PHSEG1_3TQ|PRSEG_1TQ);                  
    spi_writebyte(CNF3,PHSEG2_3TQ);                                                                                 
    spi_writebyte(CANINTF,0x00);                                                                        
    spi_writebyte(CANINTE,0x03);        
    spi_writebyte(RXB0CTRL,0x60);                                                                  

        //spi_writebyte(RXB1CTRL,0x40);                                                            
    spi_writebyte(RXM0SIDH,0xff);
    spi_writebyte(RXM0SIDL,0xff);
    spi_writebyte(RXM0EID8,0xff);
    spi_writebyte(RXM0EID0,0xff);
  
//        spi_writebyte(RXM1SIDH,0xff);
//        spi_writebyte(RXM1SIDL,0xff);
//        spi_writebyte(RXM1EID8,0xff);
//        spi_writebyte(RXM1EID0,0xff);

    spi_writebyte( BFPCTRL, 0 );                                                         
    spi_writebyte( TXRTSCTRL, 0 );                                          
    mcp2515_bitmodity(CANCTRL,0xE0,0x00);
}

int main (void)
{
    uint8_t txbuf[8];
    uint8_t i=0;
    wiringPiSetup();
    init_mcp2515();

    for(i=0;i<8;i++)
    {
        txbuf[i]=0;
    }

    while(1)
    {
        delay(100);
        txbuf[0]=i;
        printf("mcp2515 txbuf[0]=%x!\r\n",txbuf[0]);
        if(can_tx_flag==0)
        {
            can_send(txbuf);
        }
        if(can_rx_flag==1)
        {
            can_rx_flag=0;
            printf("can rxdat: %x %x %x %x %x %x %x %x\r\n",rxbuf[0],rxbuf[1],rxbuf[2],rxbuf[3],rxbuf[4],rxbuf[5],rxbuf[6],rxbuf[7]);
        }
        
        i++;
    }
	return 0;
}

 

三、测试结果

开发板与CAN卡调试助手之间收发通信

 

火辣西米秀

 CAN收发测试一般都能测过

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火辣西米秀 发表于 2023-8-5 08:34  CAN收发测试一般都能测过

是的

jobszheng5

楼主，这种大板上在CAN通讯的实时性上面如何啊？

 

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jobszheng5 发表于 2023-8-6 10:15 楼主，这种大板上在CAN通讯的实时性上面如何啊？  

接收使用的中断，数据量不大，实时性还可以。

jobszheng5

我总觉得这种系统下，跑CAN的实时性无法满足

TL-LED

jobszheng5 发表于 2023-8-7 11:07 我总觉得这种系统下，跑CAN的实时性无法满足

测试运行的任务少，觉得还可以， 没有具体到项目中测试。

freebsder

搞点压力来测