单片机PID温度控制程序 -

#include <REGX51.H>
#define Kp 5 //比例系数
#define Ki 2 //积分系数
#define Kd 1 //微分系数
unsigned char m,n,p; //温度的十位个位小数
unsigned char test_temp; //温度检定标志
unsigned char key_set_flag; //按键设定进入标志
unsigned char flag=1; //按键保持标志
unsigned char Change_step=1,e; //温度设置步进
unsigned char T0_H = 0,T0_L = 0,T1_H=0,T1_L=0;
int Real_temp; //实际温度值
int Set_temp; //设置温度
int Disp_temp; //显示温度
int last_error; //上次误差
float I_term; //前面温差和
bit key_hold;
unsigned char dj_flag1;
bit key_flag;
int PID_MAX;
unsigned int out,PWMT,counter,kk,outp,dz;
int time; //脉冲触发时刻
sbit DQ=P2^4; //定义DS18b20的管脚
sbit RS = P2^0; //定义液晶屏定义端口
sbit RW = P2^1; //定义液晶屏定义端口
sbit EN = P2^2; //定义液晶屏定义端口
sbit k1=P1^0;
sbit k2=P1^1;
sbit k3=P1^2;
sbit k4=P1^3;
sbit k5=P1^4;
sbit k6=P1^5;
sbit k7=P1^6;
sbit k8=P1^7;
sbit PWM=P2^7; //PWM控制脚
sbit DJ1=P2^3;
sbit DJ2=P2^5;
sbit led1=P3^5;
sbit led2=P3^6;
sbit led3=P3^7;
sbit led4=P3^4;
#define RS_CLR RS=0
#define RS_SET RS=1
#define RW_CLR RW=0
#define RW_SET RW=1
#define EN_CLR EN=0
#define EN_SET EN=1
unsigned char aa[]={' ',' ','S','e','t','u','p',':',' ',' ','.',' ',' ',' ',' ',' '}; //Distance
unsigned char bb[]={' ',' ',' ',' ',' ',' ',' ','.',' ',' ',' ',' ',' ',' ',' ',' '};
void LCD_Write_String(unsigned char x,unsigned char y,unsigned char *s);
void LCD_Write_Char(unsigned char x,unsigned char y,unsigned char Data);
void init(); //初始化
/*------------------------------------------------
uS延时函数，含有输入参数 unsigned char t，无返回值
unsigned char 是定义无符号字符变量，其值的范围是
0~255 这里使用晶振12M，精确延时请使用汇编,大致延时
长度如下 T=tx2+5 uS
------------------------------------------------*/
void DelayUs2x(unsigned char t)
{
while(--t);
}
/*------------------------------------------------
mS延时函数，含有输入参数 unsigned char t，无返回值
unsigned char 是定义无符号字符变量，其值的范围是
0~255 这里使用晶振12M，精确延时请使用汇编
------------------------------------------------*/
void DelayMs(unsigned char t)
{
while(t--) //大致延时1mS
{
DelayUs2x(245);
DelayUs2x(245);
}
}
/*****延时子程序*****/
void delay(unsigned int t)
{
for(;t>0;t--);
}
void delay_50us(unsigned int t)
{
unsigned char j;
for(;t>0;t--)
for(j=19;j>0;j--);
}
/*****初始化DS18B20*****/
unsigned char Init_DS18B20(void)
{
unsigned char x=0;
DQ = 1; //DQ复位
delay(8); //稍做延时
DQ = 0; //单片机将DQ拉低
delay(80); //精确延时，大于480us
DQ = 1; //拉高总线
delay(8);
x = DQ; //稍做延时后，如果x=0则初始化成功，x=1则初始化失败
delay(4);
return x;
}
/*****读一个字节*****/
unsigned char ReadOneChar(void)
{
unsigned char i=0;
unsigned char dat = 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(4);
}
return(dat);
}
/*****写一个字节*****/
void WriteOneChar(unsigned char dat)
{
unsigned char i=0;
for (i=8; i>0; i--)
{
DQ = 0;
DQ = dat&0x01;
delay(4);
DQ = 1;
dat>>=1;
}
delay(4);
}
/*****读取温度*****/
int ReadTemperature(void)
{
unsigned char a=0;
unsigned char b=0;
unsigned int t=0;
t=Init_DS18B20();
if(t) return Real_temp;
WriteOneChar(0xCC); //跳过读序号列号的操作
WriteOneChar(0x44); //启动温度转换
t=Init_DS18B20();
if(t) return Real_temp;
WriteOneChar(0xCC); //跳过读序号列号的操作
WriteOneChar(0xBE); //读取温度寄存器
a=ReadOneChar(); //读低8位
b=ReadOneChar(); //读高8位
t=b;
t<<=8;
t=t|a;
if(t<=0||t>0x900)
return Real_temp;
t=t*0.625+0.5;
return(t);
} void keywendu_set(void)
{
if(k1==0)
{
delay(10);
while(!k1);
key_hold=~key_hold;
}
if(key_hold==0)
{
if(k2==0)
{
delay(10);
while(!k2);
Set_temp=Set_temp+1;
if(Set_temp>99)
Set_temp=99;
}
if(k3==0)
{
delay(10);
while(!k3);
Set_temp=Set_temp-1;
if(Set_temp<1)
Set_temp=1;
}
aa[8]=10*Set_temp/100+'0';
aa[9]=10*Set_temp/10%10+'0';
aa[11]=10*Set_temp%10+'0';
LCD_Write_String(0,0,aa);
}
}
void keyzhuansu_set(void)
{
if(k4==0)
{
delay(10);
while(!k4);
key_flag=~key_flag;
}
if(key_flag==0) //手动模式
{
led4=1;
if(k5==0)
{
DJ1=1;
DJ2=0;
}
else if(k6==0)
{
DJ1=0;
DJ2=1;
}
else
{
DJ1=0;
DJ2=0;
}
}
else
{
led4=0;
if(k5==0)
{
delay(10);
while(!k5);
dj_flag1=1;
}
if(k6==0)
{
delay(10);
while(!k6);
dj_flag1=2;
}
if(k7==0)
{
delay(10);
while(!k7);
dj_flag1=3;
}
if(dj_flag1==1)
{
DJ1=1;
DJ2=0;
}
else if(dj_flag1==2)
{
DJ1=0;
DJ2=1;
}
else
{
DJ1=0;
DJ2=0;
}
}
}
int PID(int Set_value,int Real_value) //标准PID温度控制算法
{
float uk ,uk1 ,duk;
int pid_out,e ,e1 ,e2;
e=Set_value-Real_value;//误差量
duk=Kp*(e-e1)+Ki*e+Kd*(e-2*e1+e2); //+Kd*(e-2e1+e2)
uk=uk1+duk;
pid_out=(int)uk;
uk1=uk;
e2=e1;
e1=e;
if(pid_out>1000)
{
pid_out=998;
}
else if(pid_out<2)
{
pid_out=2;
}
outp=pid_out;
return(pid_out);
}
void T0_int(void) interrupt 1
{
T0_H = (65535-2000)/256; //PWM=1高位初值计算
T0_L = (65535-2000)%256; //PWM=1低位初值计算
TH0 = T0_H; //通的初值高位
TL0= T0_L; //通的初值低位
kk++;
if(kk>1000)
kk=0;
if(kk>outp)
PWM=1;
else PWM=0;
// }
}
void main()
{
PWMT=128; //128级步进PWM控制
PID_MAX=PWMT;
counter=0;
out=0;
PWM=1;
I_term=0;
last_error=0;
Set_temp=30; //初始设定温度为30度
init();
Real_temp=Set_temp*10;
key_hold=1;
Init_DS18B20();
WriteOneChar(0xCC); //跳过读序号列号的操作
WriteOneChar(0x44); //启动温度转换
delay_50us(150); //等待温度测量 delay_50us(15000);
TMOD=0x01; //定时器0模式1
TR0=1;
ET0=1;
IT0=1;
EX0=1;
EA=1;
aa[12]=0xdf;
aa[13]=0x43;
bb[9]=0xdf;
bb[10]=0x43;
aa[8]=10*Set_temp/100+'0';
aa[9]=10*Set_temp/10%10+'0';
aa[11]=10*Set_temp%10+'0';
LCD_Write_String(0,0,aa);
while(1)
{
counter++;
DelayMs(500);
if(counter>4)
{
test_temp=1; //进行一次温度检定
counter=0;
}
if(test_temp) //温度检定标志置位，进入温度PID调节
{
Real_temp=ReadTemperature(); //采集当前实际温度
test_temp=0; //检定完成，清温度检定标志
bb[5]=Real_temp/100+'0';
bb[6]=Real_temp/10%10+'0';
bb[8]=Real_temp%10+'0';
LCD_Write_String(0,1,bb);
if((Real_temp/10)<(Set_temp))
{
led1=~led1;
led2=1;
}
else if((Real_temp/10)>(Set_temp))
{
led3=~led3;
led2=1;
}
else
{
led1=1;
led2=0;
led3=1;
}
}
if((Real_temp/10)<(Set_temp-1))
{
outp=998;
}
else if((Real_temp/10)>(Set_temp+1))
{
outp=2;
}
else
{
PID(Set_temp*10,Real_temp); //PID程序
}
keywendu_set(); //按键温度设置
keyzhuansu_set();
}
}
///////////////////////////////////////////////////
// 液晶屏显示处理
///////////////////////////////////////////////////
void write_com(unsigned char com) //写命令
{
RS_CLR;
RW_CLR;
P0=com;
DelayMs(1);
EN_SET;
DelayMs(1);
EN_CLR;
}
void write_data(unsigned char date) //写一个字符
{
RS_SET;
RW_CLR;
P0=date;
DelayMs(1);
EN_SET;
DelayMs(1);
EN_CLR;
}
void init() //初始化
{
write_com(0x38);
write_com(0x0c);
write_com(0x06);
write_com(0x01);
}
/*------------------------------------------------
写入字符串函数
------------------------------------------------*/
void LCD_Write_String(unsigned char x,unsigned char y,unsigned char *s)
{
if (y == 0)
{
write_com(0x80 + x);
}
else
{
write_com(0xC0 + x);
}
while (*s)
{
write_data( *s);
s ++;
}
}

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