pid温度控制51c语言程序

#include <reg51.h>

unsigned int set=20;   //设定温度存储单元

unsigned int tvaluet;     // 前一次温度存储单元

unsigned int tvalue;      //当前温度值

unsigned char pwm;    //pwm输出缓存

sbit DQ =P1^0;            //定义通信端口

sbit k1=P3^5;             //功能键

sbit k2=P3^6;             //加一键

sbit k3=P3^7;           //减一键

sbit re=P1^1;             //加热

sbit le=P1^2;             //制冷



unsigned char  tab[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0X83,0Xf8,0X80,0X98};

                          //0,    1,   2   3    4    5    6    7    8    9// 


//*************延时函数*********************

void delay(unsigned int i)

{

     while(i--);

    

}



//***************显示函数****************

void display2(unsigned char m)

{unsigned char disp[3];

 unsigned char i;

 disp[0]=m/100;

 disp[1]=m%100/10;

 disp[2]=m%10;   

 for(i=0;i<3;i++)

 {SBUF=tab[disp];