51单片机的PID控制DS18B20水温源代码+电路原理图 -

#include ‘reg52.h’
#include ‘stdio.h’
#define uchar unsigned char
#define uint unsigned int
sbit s1=P2^0;
sbit s2=P2^1;
sbit s3=P2^2;
sbit s4=P2^3;
sbit s5=P2^4;
sbit ds=P2^5;
sbit beep=P2^6;
sbit rd=P1^0;
sbit rs=P1^1;
sbit wr=P1^2;
sbit lcden=P1^3;
sbit PWM=P1^6;
sbit led1=P1^4;
sbit led2=P1^5;
uchar set_temp,keytemp;
uint temp;
uchar c;
bit flag,flag1,flag2;
float f_temp,t;
int timecount,z;
float KP,KI,KD;
float e1,e2,e3;
float uk,duk;
uchar HighL,HighH,PWMH;
float k;
uchar code table[]={"设定温度："};
uchar code table1[]={"实测温度："};
uchar code table2[]={"加热"};
uchar code table3[]={"保温"};
uchar code table4[]={"作者：0903锋仔@"};
uchar code table5[]={"系统初始化"};
uchar code table6[]={"measured Temperature"};
uchar code table7[]={"水温控制系统设计"};
uchar code table8[]={" "};
void delay(uint z)//延时函数，延时5ms
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
void keyscan()
{
if(set_temp>=100)//将设定温度限定在0-100度之间
set_temp=100;
if(set_temp<=0)
set_temp=0;
if(s5==0)//此键按下设定温度加5
{
delay(10);
if(s5==0)
{
flag1=0;
set_temp+=5;
if(set_temp>=100)
{
set_temp=100;
beep=0;
delay(1000);
beep=1;
}
}while(s5==0);
}
if(s4==0)//此键按下设定温度减5
{
delay(10);
if(s4==0)
{
flag1=0;
set_temp-=5;
if(set_temp<=0)
{
set_temp=0;
beep=0;
delay(1000);
beep=1;
}
}while(s4==0);
}
if(s3==0)//此键按下设定温度加1
{
delay(10);
if(s3==0)
{
flag1=0;
set_temp++;
if(set_temp==100)
{
set_temp=100;
beep=0;
delay(1000);
beep=1;
}
}while(s3==0);
}
if(s2==0)//此键按下设定温度减1
{
delay(10);
if(s2==0)
{
flag1=0;
set_temp--;
if(set_temp==0)
{
set_temp=0;
beep=0;
delay(1000);
beep=1;
}
}while(s2==0);
}
if(s1==0)//确定加热状态（加热与不加热）
{
delay(10);
if(s1==0)
{
flag1=1;
}
while(s1==0);
}
}
void dsreset()//DS18B20复位函数
{
uint i;
ds=0;
i=103;
while(i>0)i--;
ds=1;
i=4;
while(i>0)i--;
}
bit tempreadbit()//从DS18B20 RAM读一位数据
{
uint i;
bit dat;
ds=0;i++;
ds=1;i++;i++;
dat=ds;
i=8;while(i>0)i--;
return(dat);
}
uchar tempread()//从DS18B20 RAM读一字节数据
{
uchar i,j,dat;
dat=0;
for(i=1;i<=8;i++)
{
j=tempreadbit();
dat=(j<<7)|(dat>>1);
}
return(dat);
}
void tempwritebyte(uchar dat)//向DS18B20写以字节的数据
{
uint i,j;
bit testb;
for(j=1;j<=8;j++)
{
testb=dat&0x01;
dat=dat>>1;
if(testb)//写1
{
ds=0;
i++;i++;
ds=1;
i=8;while(i>0)i--;
}
else//写0
{
ds=0;
i=8;while(i>0)i--;
ds=1;
i++;i++;
}
}
}
void tempchange()//启动温度转换
{
dsreset();
delay(1);
tempwritebyte(0xcc);
tempwritebyte(0x44);
}
float get_temp()//温度值读取与处理函数
{
uchar a,b;
dsreset();
delay(1);
tempwritebyte(0xcc);
tempwritebyte(0xbe);
a=tempread();
b=tempread();
temp=b;
temp<<=8;
temp=temp|a;
f_temp=(float)(temp*0.0625);
f_temp=f_temp*10;
return(f_temp);
}
void write_com(uchar com)//向12864写指令
{
rs=0;
wr=0;
delay(1);
P0=com;
lcden=1;
delay(1);
lcden=0;
delay(1);
}
void write_date(uchar date)//向12864写数据
{
rs=1;
wr=0;
delay(1);
P0=date;
lcden=1;
delay(1);
lcden=0;
delay(1);
}
void display(float m,uchar n)//显示设定温度、实测温度、加热状态
{
uint i,j;
float b;
float p;
uchar a1,a2,a3;
uchar b1,b2,b3,b4;
if(n<100)
{
a1=0;
a2=n/10;
a3=n;
}
else
{
a1=1;
a2=0;
a3=0;
}
p=m;
j=(uint)(p*10);
b1=(uchar)(j/1000);
b2=(uchar)(j00/100);
b3=(uchar)(j0/10);
b4=(uchar)(j);
write_com(0x90+5);//显示设定温度
write_date(0x30+a1);
write_date(0x30+a2);
write_date(0x30+a3);
write_com(0x88+5);//显示实测温度
write_date(0x30+b1);
write_date(0x30+b2);
write_date(0x2e);
write_date(0x30+b3);
write_date(0x30+b4);
b=((float)(b1*100+b2*10+b3))/10.0;
i=0;
if((b+0.2)
{
led1=0;
write_com(0x98+1);
while(table2[i]!='\0')
{
write_date(table2[i]);
i++;
}
flag2=1;
}
else
{
led1=1;
i=0;
write_com(0x98+1);
while(table8[i]!='\0')
{
write_date(table8[i]);
i++;
}
i=0;
if((b=n)||((b>n)&&((b-0.2)<=n))||((b=n)))
{
led2=0;
write_com(0x98+4);
while(table3[i]!='\0')
{
write_date(table3[i]);
i++;
}
}
}
if(flag2==1)
{
flag2=0;
led2=1;
i=0;
write_com(0x98+4);
while(table8[i]!='\0')
{
write_date(table8[i]);
i++;
}
}
}
void conversion()//定时器2初值处理函数
{
uint temp2;
temp2=65536-PWMH*10;
HighH=temp2/256;
HighL=temp2%6;
}
void senddate(float y)
{
// uint i;
if(flag==1)
{
ES=0;
flag=0;
c=0;
TI=1;
printf("The measured temp:%f",y);
// SBUF=1;
while(!TI);
TI=0;
ES=1;
}
}
void init()//初始化函数
{
uint i,j;
TMOD=0x21;
TH1=0xfd;
TL1=0xfd;
TH0=(65536-50000)/256;
TL0=(65536-50000)%6;
PWMH=0;
conversion();
TH2=(65536-50000)/256;
TL2=(65536-50000)%6;
rd=1;
lcden=0;
write_com(0x30);
write_com(0x0c);
write_com(0x01);
write_com(0x90);
while(table5[i]!='\0')//系统初始化
{
write_date(table5[i]);
i++;
delay(20);
}
for(j=0;j<=1;j++)//6个点的三次循环
{
write_com(0x88+4);
for(i=0;i<=5;i++)
{
write_date(0x2e);
delay(200);
}
delay(100);
write_com(0x88+4);
for(i=0;i<=5;i++)
{
write_date(0x20);
}
delay(100);
}
i=0;
write_com(0x80);//显示水温控制系统设计标题
while(table7[i]!='\0')
{
write_date(table7[i]);
i++;
}
i=0;
write_com(0x90);//显示设定温度
while(table[i]!='\0')
{
write_date(table[i]);
i++;
}
i=0;
write_com(0x88);//显示实测温度
while(table1[i]!='\0')
{
write_date(table1[i]);
i++;
}
// tempwritebyte(0x4e);//设定DS18B20的分辨率为11位
// tempwritebyte(0x5f);
PWM=0;
e1=0;
e2=0;
e3=0;
duk=0;
uk=0;
KP=20;//PID控制算法参数
KI=0.061;
KD=30;
REN=1;//串口通信设置
SM0=0;
SM1=1;
ET0=1;
ET2=1;
TR0=1;
TR1=1;
TR2=1;//启动定时器2
EA=1;
ES=1;
}
void main()
{
init();
while(1)
{
keyscan();//调用键盘扫描函数
tempchange();//启动温度转换
t=get_temp();//提取实测温度
display(t,set_temp);//显示设定温度和实测温度
senddate(t);//向上位机发送数据函数
if((flag1==1))
{
if(timecount>=375)
{
timecount=0;
e1=set_temp-t;
duk=(KP*(e1-e2)+KI*e1+KD*(e1-2*e2+e3));//PID控制算法式
uk=uk+duk;
if(e1>=75)
{
z=4;
}
else if(e1>=50)
{
z=3;
}
else if(e1>=10)
{
z=2;
}
else
z=1;
}
if(uk>=2500)uk=2500;
if(uk<=0)uk=0;
if(uk<=0)
{
ET0=0;
ET2=0;
PWM=0;
}
else
{
ET0=1;
ET2=1;
PWMH=(uchar)uk;
k=(float)uk;
}
e3=e2;
e2=e1;
conversion();//调用定时器2初值处理函数
}
else
{
ET0=0;
ET2=0;
PWM=0;
}
}
}
void timer0() interrupt 1//定时器1中断
{
TH1=(65536-50000)/256;
TL1=(65536-50000)%6;
timecount++;
TH2=HighH;
TL2=HighL;
PWM=1;
}
void ser() interrupt 4//串口中断
{
RI=0;
c=SBUF;
flag=1;
}
void Timer2() interrupt 5//用定时器2控制PWM占空比
{
TF2=0;
PWM=0;
}

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