51单片机中用keil编写具体程序实现：1602液晶显示器显示DS18B20与HD-SR04数据，距离小于10cm时唤醒总系统，温度大于37度小于40度时蜂鸣器发响，温度大于34度小于等于37度时带动步进电机

以下是基于51单片机的keil编写的程序实现：

#include <reg51.h>
#include <intrins.h>

#define LCD_data P0         //1602液晶数据线
sbit LCD_RS = P2^0;         //1602液晶RS引脚
sbit LCD_RW = P2^1;         //1602液晶RW引脚
sbit LCD_EN = P2^2;         //1602液晶EN引脚

sbit DQ = P3^4;             //DS18B20数据线
sbit TRIG = P3^5;           //HC-SR04触发引脚
sbit ECHO = P3^6;           //HC-SR04回响引脚
sbit BEEP = P3^7;           //蜂鸣器引脚

sbit StepP = P1^0;          //步进电机正转引脚
sbit StepN = P1^1;          //步进电机反转引脚
sbit StepC = P1^2;          //步进电机控制引脚

unsigned char dis[16];      //存储显示的字符

//延时函数
void Delay(unsigned int i)
{
    while(i--);
}

//1602液晶写命令
void Write_Cmd(unsigned char cmd)
{
    LCD_RS = 0;
    LCD_RW = 0;
    LCD_data = cmd;
    LCD_EN = 1;
    _nop_();
    _nop_();
    LCD_EN = 0;
    Delay(10);
}

//1602液晶写数据
void Write_Data(unsigned char dat)
{
    LCD_RS = 1;
    LCD_RW = 0;
    LCD_data = dat;
    LCD_EN = 1;
    _nop_();
    _nop_();
    LCD_EN = 0;
    Delay(10);
}

//1602液晶初始化
void LCD_Init()
{
    Write_Cmd(0x38);    //设置16*2，5*7点阵，8位数据接口
    Write_Cmd(0x0c);    //开显示，光标不显示
    Write_Cmd(0x06);    //文字向右走，光标不动
    Write_Cmd(0x01);    //清屏
}

//DS18B20读取温度函数
float Read_Temp(void)
{
    unsigned char tempdata[2];
    unsigned int temp;
    float t;
    unsigned char i;

    DQ = 1;                 //开始通讯
    Delay(5);
    DQ = 0;
    Delay(80);
    DQ = 1;
    Delay(10);
    if(DQ)
    {
        return 0;
    }
    Delay(50);
    for(i = 0; i < 2; i++)
    {
        tempdata[i] = 0;
    }
    for(i = 0; i < 8; i++)
    {
        DQ = 0;             //开始通讯
        tempdata[0] >>= 1;
        tempdata[1] >>= 1;
        DQ = 1;
        if(DQ)
        {
            tempdata[0] |= 0x80;
        }
        Delay(5);
    }
    for(i = 0; i < 8; i++)
    {
        DQ = 0;             //开始通讯
        tempdata[0] >>= 1;
        tempdata[1] >>= 1;
        DQ = 1;
        if(DQ)
        {
            tempdata[1] |= 0x80;
        }
        Delay(5);
    }
    for(i = 0; i < 16; i++)
    {
        DQ = 0;             //开始通讯
        temp >>= 1;
        DQ = 1;
        if(DQ)
        {
            temp |= 0x8000;
        }
        Delay(5);
    }
    t = (float)temp / 16.0;
    return t;
}

//HC-SR04读取距离函数
unsigned int Read_Distance(void)
{
    unsigned int time;
    TRIG = 0;
    Delay(5);
    TRIG = 1;
    Delay(10);
    TRIG = 0;
    while(!ECHO);
    time = 0;
    while(ECHO)
    {
        time++;
        Delay(5);
    }
    return time / 58;
}

//步进电机正转函数
void Step_Forward()
{
    StepC = 1;
    StepP = 0;
    StepN = 1;
    Delay(100);
    StepC = 0;
    Delay(100);
}

//步进电机反转函数
void Step_Backward()
{
    StepC = 1;
    StepP = 1;
    StepN = 0;
    Delay(100);
    StepC = 0;
    Delay(100);
}

//主函数
void main()
{
    float temp;
    unsigned int dist;

    LCD_Init();                 //1602液晶初始化

    while(1)
    {
        temp = Read_Temp();     //读取温度
        dist = Read_Distance(); //读取距离

        //显示温度和距离
        sprintf(dis, "T:%.2fC D:%dcm", temp, dist);
        for(i = 0; i < 16; i++)
        {
            Write_Data(dis[i]);
        }

        if(dist < 10)           //距离小于10cm时唤醒总系统
        {
            //唤醒总系统
        }

        if(temp > 37.0 && temp < 40.0)  //温度大于37度小于40度时蜂鸣器响
        {
            BEEP = 1;
        }
        else
        {
            BEEP = 0;
        }

        if(temp > 34.0 && temp <= 37.0) //温度大于34度小于等于37度时带动步进电机
        {
            Step_Forward();
        }
        else
        {
            Step_Backward();
        }
    }
}