基于单片机PID算法的恒温控制系统仿真与程序源码设计(DS18B20传感器)

#include<reg52.h> #include<intrins.h> #include<math.h> #include<string.h> struct PID { unsigned int SetPoint; // 设定目标 Desired Value unsigned int Proportion; // 比例常数 Proportional Const unsigned int Integral; // 积分常数 Integral Const unsigned int Derivative; // 微分常数 Derivative Const unsigned int LastError; // Error[-1] unsigned int PrevError; // Error[-2] unsigned int SumError; // Sums of Errors }; struct PID spid; // PID Control Structure unsigned int rout; // PID Response (Output) 响应输出 unsigned int rin; // PID Feedback (Input)//反馈输入 unsigned char high_time,low_time,count=0;//占空比调节参数 #define uchar unsigned char #define uint unsigned int sbit output=P1^0; sbit ds=P3^2; sbit DQ=P3^2;//ds18b20与单片机连接口 sbit lcden=P2^7;//LCE使能引脚 sbit lcdrs=P2^5; sbit lcdrw=P2^6; sbit ledred=P1^6; sbit ledgreen=P1^7; sbit key0=P2^0;//按键引脚 sbit key1=P2^1; uchar set[2]={0}; uchar code str1[]="now temp: C"; uchar code str2[]="set temp: C"; uchar code table[]={0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39}; uchar n,num; int set_temper=30,temper,temp; //温度变量定义 unsigned int s; float f_temp;//转换后的温度 uint tvalue; uchar tflag;//温度正负标志 void delay(i)//延时函数 { uint j; for(i;i>0;i--) for(j=110;j>0;j--); } void wr_com(uchar ml)//写命令 { lcdrs=0; P0=ml; delay(5); lcden=1; delay(5); lcden=0; } void wr_data(uchar shuju)//写数据 { lcdrs=1; //lcden=1; P0=shuju; delay(5); lcden=1; delay(5); lcden=0; } void init() //按照时序操作的初始化 { lcdrw=0; wr_com(0x38);//显示模式设置，设置为16*2显示，5*7点阵，八位数据口 wr_com(0x0c);//开显示，但不开光标，光标不闪 wr_com(0x06);//显示光标移动设置 wr_com(0x01);// 清屏 wr_com(0x80); // 数据指针初始化 for(num=0;num<16;num++) { wr_data(str1[num]);//now temp } wr_com(0x80+0x40); //地址初始化 for(num=0;num<16;num++) { wr_data(str2[num]);//set temp } } /*************************DS1820程序****************************/ void delay_18B20(unsigned int i)//延时1微秒 { while(i--); } void ds1820rst(void)/*ds1820复位*/ { unsigned char x=0; DQ = 1; //DQ复位 delay_18B20(4); //延时 DQ = 0; //DQ拉低 TR0=0; delay_18B20(100); //精确延时大于 TR0=1; DQ = 1; //拉高 delay_18B20(40); } uchar ds1820rd(void)/*读数据*/ { unsigned char i=0; unsigned char dat = 0; TR0=0; for (i=8;i>0;i--) { DQ = 0; //给脉冲信号 dat>>=1; DQ = 1; //给脉冲信号 if(DQ) dat|=0x80; delay_18B20(10); } return(dat); } void ds1820wr(uchar wdata)/*写数据*/ { unsigned char i=0; TR0=0; for (i=8; i>0; i--) { DQ = 0; DQ = wdata&0x01; delay_18B20(10); DQ = 1; wdata>>=1; } } uint get_temper()//获取温度 { uchar a,b; ds1820rst(); ds1820wr(0xcc);//*跳过读序列号*/ ds1820wr(0x44);//*启动温度转换*/ ds1820rst(); ds1820wr(0xcc);//*跳过读序列号*/ ds1820wr(0xbe);//*读取温度*/ a=ds1820rd(); b=ds1820rd(); tvalue=b; tvalue<<=8; tvalue=tvalue|a; TR0=1; if(tvalue<0x0fff) tflag=0; else {tvalue=~tvalue+1;tflag=1;} tvalue=tvalue*(0.625);//温度值扩大10倍，精确到1位小数 temp=tvalue; return temp; } void dis_temp(int t)//显示温度 { uchar d0,d1,d2,d3; //t=26; if(tflag==0) { d0=t/1000+0x30; d1=t%1000/100+0x30; d2=t%100/10+0x30; d3=t%10+0x30; if(d0==0x30) { wr_com(0x80+9); wr_data(d1); wr_com(0x80+10); wr_data(d2); wr_com(0x80+11); wr_data(0x2e); wr_com(0x80+12); wr_data(d3); } else { wr_com(0x80+9); wr_data(d0); wr_com(0x80+10); wr_data(d1); wr_com(0x80+11); wr_data(d2); wr_com(0x80+12); wr_data(' '); } } else { wr_com(0x80+9); wr_data('-'); wr_com(0x80+10); wr_data(d1); wr_com(0x80+11); wr_data(d2); wr_com(0x80+12); wr_data(' '); //wr_com(0x80+12); //wr_data(d3); } wr_com(0x80+14); wr_data(0xdf); temper=t/10; } void keyscan()//键盘扫描 { if(key0==0) { delay(1); if(key0==0) { while(!key0); delay(1); while(!key0); set_temper++; } set[0]=set_temper/10; //获得设置温度显示值 set[1]=set_temper%10; wr_com(0x80+0x40+9); wr_data(table[set[0]]); delay(1); wr_com(0x80+0x40+10); wr_data(table[set[1]]); delay(1); //wr_com(0x80+0x40+11); //wr_data(0x2e); //wr_com(0x80+0x40+14); //wr_data(0xdf); delay(1); } if(key1==0) { delay(3);//延时去抖 if(key1==0) { while(!key1); delay(3); while(!key1); set_temper--;//温度减 if(set_temper==0) {set_temper=0;} } set[0]=set_temper/10; //获得设置温度显示值 set[1]=set_temper%10; wr_com(0x80+0x40+9); //显示设置温度值 wr_data(table[set[0]]); delay(1); wr_com(0x80+0x40+10); wr_data(table[set[1]]); delay(1); //wr_com(0x80+0x40+11); //wr_data(0x2e); wr_com(0x80+0x40+14); wr_data(0xdf); delay(1); } } void PIDInit (struct PID *pp) { memset ( pp,0,sizeof(struct PID)); //用参数0初始化pp } unsigned int PIDCalc( struct PID *pp, unsigned int NextPoint ) //PID计算 { unsigned int dError,Error; Error = pp->SetPoint - NextPoint; // 偏差 pp->SumError += Error; // 积分 dError = pp->LastError - pp->PrevError; // 当前微分 pp->PrevError = pp->LastError; pp->LastError = Error; return (pp->Proportion * Error//比例 + pp->Integral * pp->SumError //积分项 + pp->Derivative * dError); // 微分项 } /*********************************************************** 温度比较处理子程序 ***********************************************************/ void compare_temper(void) { unsigned char i; if(set_temper>temper) //设置温度大于当前温度 { ledred=0; ledgreen=1; if(set_temper-temper>1) //温度相差1度以上 { high_time=100; low_time=0; } else //设置温度不大于当前温度 { for(i=0;i<10;i++) { get_temper(); rin = s; // Read Input rout = PIDCalc ( &spid,rin ); // Perform PID Interation } if (high_time<=100) high_time=(unsigned char)(rout/800); else high_time=100; low_time= (100-high_time); } } else if(set_temper<=temper) //设置温度不大于当前温度 { ledred=1; ledgreen=0; if(temper-set_temper>0) //温度相差0度以上 { high_time=0; low_time=100; } else { for(i=0;i<10;i++) { get_temper(); rin = s; // Read Input rout = PIDCalc ( &spid,rin ); // Perform PID Interation } if (high_time<100) high_time=(unsigned char)(rout/10000); else high_time=0; low_time= (100-high_time); } } } /***************************************************** T0中断服务子程序，用于控制电平的翻转 ,40us*100=4ms周期 ******************************************************/ void serve_T0() interrupt 1 using 1 { if(++count<=(high_time)) output=0; else if(count<=100) { output=1; } else count=0; TH0=0x2f; TL0=0x40; } /***********主函数**********/ void main(void) { unsigned char i; init();//LCD初始化 TMOD=0x01; TH0=0x2f; TL0=0x40; EA=1; ET0=1; TR0=1; high_time=50; low_time=50; PIDInit ( &spid ); // Initialize Structure spid.Proportion= 10; // Set PID Coefficients spid.Integral = 8; spid.Derivative =6; spid.SetPoint =100; // Set PID Setpoint set[0]=set_temper/10; set[1]=set_temper%10; wr_com(0x80+0x40+9); //显示设置温度 wr_data(table[set[0]]); delay(1); wr_com(0x80+0x40+10); wr_data(table[set[1]]); delay(1); wr_com(0x80+0x40+14); //显示温度符号 wr_data(0xdf); delay(1); while(1) { keyscan(); //按键扫描 for(i=0;i<10;i++) //循环10次 { dis_temp(get_temper()); //显示温度值 if((key0==0)||(key1==0)) break; //如果有按键退出显示循环 } if((