基于can总线的STC12C5A60S2单片机控制直流电机正反转

要基于CAN总线控制直流电机正反转，您需要准备以下硬件和软件：

硬件：
- STC12C5A60S2单片机
- 直流电机
- CAN总线收发器
- CAN总线适配器
- 电源模块
- 连接线等

软件：
- Keil C51集成开发环境
- STC-ISP下载器
- CAN总线通信协议库

下面是基于CAN总线的STC12C5A60S2单片机控制直流电机正反转的代码实现：

#include <reg52.h>
#include <intrins.h>

#define uchar unsigned char
#define uint unsigned int

sbit CAN_EN = P3^7;
sbit DIR = P1^0;
sbit PWM = P1^1;

uchar id = 0x01; //CAN ID号
uchar code cmd1 = 0x01; //控制命令1
uchar code cmd2 = 0x02; //控制命令2

void Init_Timer0() //初始化定时器0
{
    TMOD |= 0x01; //设置为模式1，16位定时器
    TH0 = 0xFC; //定时器初值
    TL0 = 0x66;
    ET0 = 1; //开定时器0中断
    TR0 = 1; //启动定时器0
}

void Init_CAN() //初始化CAN总线
{
    P1M1 = 0x00;
    P1M0 = 0xFF;
    P3M1 &= 0x7F;
    P3M0 |= 0x80;
    CAN_EN = 0; //禁止CAN总线
    PCON |= 0x00;
    ACC = P_SW1;
    ACC &= 0xFE;
    P_SW1 = ACC;
    C_T2 = 0;
    T2CON = 0x04;
    BTR0 = 0x07;
    BTR1 = 0x98;
    ACON = 0x00;
    IE2 = 0x01;
    CAN_EN = 1; //使能CAN总线
}

void CAN_Send(uchar id, uchar cmd) //CAN总线发送函数
{
    uchar i;
    uchar buf[8] = {0};
    buf[0] = id;
    buf[1] = cmd;
    for(i = 0; i < 5; i++)
    {
        buf[i+2] = 0x00;
    }
    buf[7] = 0x00;
    Can0SendBuf(buf); //调用CAN总线发送函数
}

void main()
{
    Init_Timer0(); //初始化定时器0
    Init_CAN(); //初始化CAN总线
    while(1)
    {
        if(DIR == 0) //正转
        {
            PWM = 1;
        }
        else if(DIR == 1) //反转
        {
            PWM = 0;
        }
    }
}

void Timer0_ISR() interrupt 1 //定时器0中断服务程序
{
    static uint count = 0;
    count++;
    if(count == 500) //500ms发送一次控制命令
    {
        CAN_Send(id, cmd1);
        count = 0;
    }
    else if(count == 250) //250ms发送一次控制命令
    {
        CAN_Send(id, cmd2);
    }
}

注：以上代码仅供参考，具体的实现方式需要根据您的实际硬件和软件环境进行调整和优化。