单片机驱动MAX6675热电偶温度报警程序与Proteus仿真图 -

//****************************************************************//
// 1602液晶显示
//单片机 AT89S52 或 STC89C52RC
//功能晶振 11.0592M 波特率 9600
//****************************************************************//
#include <reg51.h>
#include <intrins.h>
//
typedef unsigned char U8; /* defined for unsigned 8-bits integer variable 无符号8位整型变量 */
typedef signed char S8; /* defined for signed 8-bits integer variable 有符号8位整型变量 */
typedef unsigned int U16; /* defined for unsigned 16-bits integer variable 无符号16位整型变量 */
typedef signed int S16; /* defined for signed 16-bits integer variable 有符号16位整型变量 */
typedef unsigned long U32; /* defined for unsigned 32-bits integer variable 无符号32位整型变量 */
typedef signed long S32; /* defined for signed 32-bits integer variable 有符号32位整型变量 */
typedef float F32; /* single precision floating point variable (32bits) 单精度浮点数（32位长度） */
typedef double F64; /* double precision floating point variable (64bits) 双精度浮点数（64位长度） */
//
#define uchar unsigned char
#define uint unsigned int
#define Data_0_time 4
#define LCD1602_DB P0
sbit LCD1602_RS = P2^0; //1602液晶引脚定义
sbit LCD1602_RW = P2^1;
sbit LCD1602_E = P2^2;
sbit xz = P2^5; //按键
sbit jia = P2^6;
sbit jian = P2^7;
sbit buzz = P3^7; //蜂鸣器
sbit SO = P1^5; //P3.6口与SO相连
sbit SCK = P1^6; //P3.4口与SCK相连
sbit CS = P1^7; //P3.5口与CS相连
//const unsigned char DevID = 1; //本机设备ID
unsigned char buffer; //串口接收缓冲区
unsigned char rcv_buffer[20];
//unsigned char send_buffer[20];
//unsigned char flag_ok = 0; //接收完毕的标识
unsigned int MAX6675_Temp;
unsigned char Flag_connect;
//unsigned char CRCH,CRCL;
//unsigned char wd[2]; //wd[]：BCD码的温度
//unsigned char flag_dis; //显示刷新的标识
//-------------------------------------------------------------------------------------------
/* 等待液晶准备好 */
void LcdWaitReady()
{
unsigned char sta;
LCD1602_DB = 0xFF;
LCD1602_RS = 0;
LCD1602_RW = 1;
do {
LCD1602_E = 1;
sta = LCD1602_DB; //读取状态字
LCD1602_E = 0;
} while (sta & 0x80); //bit7等于1表示液晶正忙，重复检测直到其等于0为止
}
/* 向LCD1602液晶写入一字节命令，cmd-待写入命令值 */
void LcdWriteCmd(unsigned char cmd)
{
LcdWaitReady();
LCD1602_RS = 0;
LCD1602_RW = 0;
LCD1602_DB = cmd;
LCD1602_E = 1;
LCD1602_E = 0;
}
/* 向LCD1602液晶写入一字节数据，dat-待写入数据值 */
void LcdWriteDat(unsigned char dat)
{
LcdWaitReady();
LCD1602_RS = 1;
LCD1602_RW = 0;
LCD1602_DB = dat;
LCD1602_E = 1;
LCD1602_E = 0;
}
/* 设置显示RAM起始地址，亦即光标位置，(x,y)-对应屏幕上的字符坐标 */
void LcdSetCursor(unsigned char x, unsigned char y)
{
unsigned char addr;
if (y == 0) //由输入的屏幕坐标计算显示RAM的地址
addr = 0x00 + x; //第一行字符地址从0x00起始
else
addr = 0x40 + x; //第二行字符地址从0x40起始
LcdWriteCmd(addr | 0x80); //设置RAM地址
}
/* 在液晶上显示字符串，(x,y)-对应屏幕上的起始坐标，str-字符串指针 */
void LcdShowStr(unsigned char x, unsigned char y, unsigned char *str)
{
LcdSetCursor(x, y); //设置起始地址
while (*str != '\0') //连续写入字符串数据，直到检测到结束符
{
LcdWriteDat(*str++);
}
}
/* 打开光标的闪烁效果 */
void LcdOpenCursor()
{
LcdWriteCmd(0x0F);
}
/* 关闭光标显示 */
void LcdCloseCursor()
{
LcdWriteCmd(0x0C);
}
/* 初始化1602液晶 */
void InitLcd1602()
{
LcdWriteCmd(0x38); //16*2显示，5*7点阵，8位数据接口
LcdWriteCmd(0x0C); //显示器开，光标关闭
LcdWriteCmd(0x06); //文字不动，地址自动+1
LcdWriteCmd(0x01); //清屏
}
void Delay(U16 j)
{ U8 i;
for(;j>0;j--)
{
for(i=0;i<27;i++);
}
}
//------------------------------------------------------------------------------------------
unsigned int MAX6675_ReadReg(void)
{
unsigned char i;
unsigned int dat;
i = 0;
dat = 0;
CS = 0;
SCK = 0;
for(i=0; i<16; i++) //get D15-D0 from 6675
{
SCK = 1;
dat = dat<<1;
if( SO==1 )
dat = dat|0x01;
SCK = 0;
}
CS = 1;
return dat;
}
/*
* 功能：延时，若干毫秒
* 参数：毫秒数
* 返回值：无
*/
void DelayMs(unsigned int i) //一个延时函数，这个函数在11.0592M晶振下的延时时间大概为1ms
{
unsigned int j,k;
for(j=i; j>0; j--)
for(k=114; k>0; k--);
}
unsigned char shezhi = 145; //数值设置默认值145
U8 shezhi_zu[3]; //默认值设置
unsigned int temph;
U8 temp_zu[4];
U8 bba_zu[2];
U8 kb[1] ;
void Display(unsigned int temp)
{
kb[0] = 0x0a;
bba_zu[0] = 0xdf;
bba_zu[1] = 0x43;
temph = temp-2; //误差
temp_zu[0] = temph/100+'0'; //温度运算
temp_zu[1] = (temph/10)%10+'0';
temp_zu[2] = temph%10+'0';
shezhi_zu[0] = shezhi/100+'0'; //数值设置1
shezhi_zu[1] = (shezhi/10)%10+'0';
shezhi_zu[2] = shezhi%10+'0';
if(Flag_connect==0) //Flag_connect为0 表示热电偶已连接，这时显示温度
{
LcdShowStr(0,0,"T:");
LcdShowStr(3,0,temp_zu);
//LcdShowStr(0,0,".");
LcdShowStr(6,0,bba_zu);//单位
LcdShowStr(0,3,"C:");
LcdShowStr(3,3,shezhi_zu);
}
else //Flag_connect为1表示热电偶未连接，这时显示FFFF
{
LcdShowStr(9,0,"ERROR");
buzz = 0;
Delay(1000);
buzz = 1;
Delay(1000);
}
}
/*****************定时器0中断服务*******************/
void Int0()
{
TMOD=0x01; //设置定时器0为工作方式1
TH0=(65536-45872)/256;
TL0=(65536-45872)%256; //装初值
EA=1;//开总中断
ET0=1;//开启定时器0中断
TR0=1;//启动定时器0
}
unsigned char num;
void T0time() interrupt 1
{
TH0=(65536-45872)/256;
TL0=(65536-45872)%256; //重装初值，保证每次进入中断函数都是50ms
num++;
if(num >= 15 ){
if (temph >= shezhi){
buzz =~ buzz;
num = 0;
} }
}
//*****************************************************/
//main()功能描述: AT89C51 11.0592MHz
void main()
{
unsigned char cnt = 11;
unsigned int t;
buzz = 1;
Int0(); //定时器0开启函数
Delay(100); //延时100US（12M晶振)
InitLcd1602(); /* 初始化1602液晶 */
while(1)
{
t=MAX6675_ReadReg();
Flag_connect=t&0x04; //读出数据的D2位是热电偶掉线标志位，该位为1表示掉线，该位为0表示连接
Flag_connect=Flag_connect>>2; //MAX6675是否在线
t = t<<1; //读出来的数据的D3~D14是温度值
t = t>>4;
MAX6675_Temp = t/4; //测得的温度单位是0.25，所以要乘以0.25（即除以4）才能得到以度为单位的温度值
/*-------------按键检测---------------------*/
if(xz == 0 )
{
Delay(50);
if(xz == 0)
{
if(jia == 0)
{
Delay(100);
if(jia == 0)
{
shezhi = shezhi+1;
}
}
}if(jian == 0){
Delay(100);
if(jian == 0)
{
shezhi = shezhi-1;
}}
}
// if (temph >= shezhi){
// buzz = 0;
// Delay(1000);
// buzz = 1;
// Delay(1000);
// }
//-------------------------------------------------
for(t=0; t<200; t++) //显示温度
{
Display(MAX6675_Temp);
}
}
}

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