基于51单片机的数字温度计，上下限，蜂鸣器报警程序 -

#include <reg52.h>
#define key P2
#define LCD1602_DB P0
sbit LCD1602_RS = P1^0;
sbit LCD1602_RW = P1^1;
sbit ADDR2 = P1^2;
sbit ADDR3 = P1^3;//
sbit ENLED = P1^4;//p1.4和p1.3是138使能端
static unsigned char D=0;
static unsigned char G=50;
sbitbuzz=P1^6;
bit flag1s = 0; //1s定时标志
unsigned char T0RH = 0; //T0重载值的高字节
unsigned char T0RL = 0; //T0重载值的低字节
extern void delay_ms(unsigned int ms);
extern void DelayX10us(unsigned char t);
void ConfigTimer0(unsigned int ms);
unsigned char IntToString(unsigned char*str, int dat);
extern bit Start18B20();
extern bit Get18B20Temp(int *temp);
extern void InitLcd1602();
extern void LcdShowStr(unsigned char x,unsigned char y, unsigned char *str);
unsigned char code table0[]="D=";
unsigned char code table1[]="G=";
unsigned char code table2[]="TEMPIS:";
unsigned char codetable3[]="DS18B20 ERR0R!";
unsigned char codetable4[]="PLEASE CHECK!";
unsigned char code table5[]="'C";
unsigned char code table7[]="Wlecometo you!!";
unsigned char code table8[]=" I am YYY_Temp!";
void main()
{
bit res;
int temp; //读取到的当前温度值
int intT, decT; //温度值的整数和小数部分
unsigned char len;
unsigned char str[12];
InitLcd1602();
LcdShowStr(0, 0, table7);
LcdShowStr(0, 1, table8);//5初始化显示5s
delay_ms(5000);
EX0=1;
IT0=1;
EA = 1; //开总中断
ConfigTimer0(10); //T0定时10ms
Start18B20(); //启动DS18B20
delay_ms(5000);
while (1)
{
if (flag1s) //每5秒更新一次温度
{
flag1s = 0;
res = Get18B20Temp(&temp); //读取当前温度
if (res) //读取成功时，刷新当前温度显示
{
intT = temp >> 4; //分离出温度值整数部分
decT = temp & 0xF; //分离出温度值小数部分
len = IntToString(str, intT);//整数部分转换为字符串
str[len++] = '.'; //添加小数点
decT = (decT*10) / 16; //二进制的小数部分转换为1位十进制位
str[len++] = decT + '0'; //十进制小数位再转换为ASCII字符
while (len < 6) //用空格补齐到6个字符长度
{
str[len++] = ' ';
}
str[len] = '\0'; //添加字符串结束符
LcdShowStr(8, 1, str); //显示到液晶屏
len= IntToString(str, D); //整数部分转换为字符串
while (len < 6) //用空格补齐到6个字符长度
{
str[len++] = ' ';
}
str[len] = '\0'; //添加字符串结束符
LcdShowStr(2, 0, str);
len = IntToString(str, G); //整数部分转换为字符串
while (len < 6) //用空格补齐到6个字符长度
{
str[len++] = ' ';
}
str[len] = '\0'; //添加字符串结束符
LcdShowStr(10, 0, str);
LcdShowStr(0,0, table0);
LcdShowStr(8,0, table1);
LcdShowStr(0,1, table2);
LcdShowStr(13,1, table5);
}
else //读取失败时，提示错误信息
{
LcdShowStr(0, 0, table3);
LcdShowStr(0, 1, table4);
}
Start18B20(); //重新启动下一次转换
}
//键盘设置上下限，0.3s扫描一次键值，同时更新一次上下限的显示
key=0xf7;
if(key!=0xf7)
{
delay_ms(10);
switch(key)
{
case0xe7:
D++;
if(D==G)D=0;
len= IntToString(str, D); //整数部分转换为字符串
while(len < 6) //用空格补齐到6个字符长度
{
str[len++]= ' ';
}
str[len]= '\0'; //添加字符串结束符
LcdShowStr(2,0, str);
break;
case0xd7:
G--;
if(G==D)G=50;
len= IntToString(str, G); //整数部分转换为字符串
while(len < 6) //用空格补齐到6个字符长度
{
str[len++]= ' ';
}
str[len]= '\0'; //添加字符串结束符
LcdShowStr(10,0, str);
break;
}
Start18B20();
delay_ms(300);//等待0.3s开始下一次扫描键值
}
//光和声音警报部分
if(D>temp*0.0625||G<temp*0.0625)//超值报警
{
ENLED= 0;
ADDR3= 1;
ADDR2= 1;
LCD1602_RW= 1;
LCD1602_RS= 0;
LCD1602_DB=0xf0;
buzz=1;
DelayX10us(17);
buzz=0;
DelayX10us(17);
ENLED= 1;//138使能关闭
}
if(D==(temp*0.0625)||G==(temp*0.0625))//等值报警
{
ENLED= 0;
ADDR3= 1;
ADDR2= 1;
LCD1602_RW = 1;
LCD1602_RS= 0;
LCD1602_DB=0xf8;
buzz=1;
DelayX10us(100);
buzz=0;
DelayX10us(100);
ENLED= 1;//138使能关闭
}
if((D<temp*0.0625&&(1.1*D)>temp*0.0625)||(G>temp*0.0625&&(0.9*G)<temp*0.0625))//接近报警
{
ENLED= 0;
ADDR3= 1;
ADDR2= 1;
LCD1602_RW= 1;
LCD1602_RS= 0;
LCD1602_DB=0xfc;
buzz=1;
DelayX10us(2500);
buzz=0;
DelayX10us(2500);
ENLED= 1;//138使能关闭
}
}
}
/* 整型数转换为字符串，str-字符串指针，dat-待转换数，返回值-字符串长度*/
unsigned char IntToString(unsigned char*str, int dat)
{
signed char i = 0;
unsigned char len = 0;
unsigned char buf[6];
if (dat < 0) //如果为负数，首先取绝对值，并在指针上添加负号
{
dat = -dat;
*str++ = '-';
len++;
}
else
{
*str++= ' ';
len++;
}
do { //先转换为低位在前的十进制数组
buf[i++] = dat % 10;
dat /= 10;
}while (dat > 0);
len += i; //i最后的值就是有效字符的个数
while (i-- > 0) //将数组值转换为ASCII码反向拷贝到接收指针上
{
*str++ = buf[i] + '0';
}
*str = '\0'; //添加字符串结束符
return len; //返回字符串长度
}
/* 配置并启动T0，ms-T0定时时间 */
void ConfigTimer0(unsigned int ms)
{
unsigned long tmp; //临时变量
tmp = 11059200 / 12; //定时器计数频率
tmp = (tmp * ms) / 1000; //计算所需的计数值
tmp = 65536 - tmp; //计算定时器重载值
tmp = tmp + 12; //补偿中断响应延时造成的误差
T0RH = (unsigned char)(tmp>>8); //定时器重载值拆分为高低字节
T0RL = (unsigned char)tmp;
TMOD &= 0xF0; //清零T0的控制位
TMOD |= 0x01; //配置T0为模式1
TH0 = T0RH; //加载T0重载值
TL0 = T0RL;
ET0 = 1; //使能T0中断
TR0 = 1; //启动T0
}
/* T0中断服务函数，完成1秒定时 */
void InterruptTimer0() interrupt 1
{
static unsigned int tmr1s = 0;
TH0 = T0RH; //重新加载重载值
TL0 = T0RL;
tmr1s++;
if (tmr1s >= 500) //定时5s
{
tmr1s = 0;
flag1s = 1;
}
}

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