51单片机设计多功能电子秤（实训项目）

一.硬件准备

1.压力传感器（HX711称重模块）

2.接线说明

如上图接线所示：称重模块HX711模块各个引脚与单片机引脚对应如下：

(1).VCC——>VCC

(2).GND——>GND

(3).SCLK——>SDA

(4).DT——>SCLK

注：引脚一定要对应接好，尤其是数据（SDA）脚和时钟（SCLK）脚

二.原理图

（一）.称重模块原理图

（二）.单片机原理图

三.代码详解及功能演示

（一）.LCD_1602显示重量

1.子代码详解（HX711获取AD值）

/*获取ad值*/
unsigned long HX711_Read(void)
{
    unsigned long count; 
    unsigned char i; 
      HX711_DOUT = 1; 
    _nop_();
    _nop_();
      HX711_SCK = 0; 
      count=0;
      for(i=0; i<24; i++)
    { 
          HX711_SCK = 1; 
          count = count << 1; 
        HX711_SCK = 0; 
          if(HX711_DOUT)
            count++; 
    } 
     HX711_SCK = 1; 
    count = count^0x800000;//第25个脉冲下降沿来时，转换数据
    _nop_();
    _nop_();
    HX711_SCK = 0;  
    return(count);
}

/*称毛皮重*/
void Get_Maopi()
{
    Weight_Maopi = HX711_Read();
//    Weight_Maopi = (unsigned int)((float)Weight_Maopi/423.15); 
}

/*称实物重*/
void Get_Weight()
{
    Weight_Shiwu = HX711_Read();  
    Weight_Shiwu = Weight_Shiwu - Weight_Maopi;
    Weight_Shiwu = (unsigned int)((float)Weight_Shiwu/429.5);    
}

2.按键控制

/*按键扫描*/
void Keyscan()
{
    if(key1 == 0)
        Delay(10);
    if(key1 == 0)
    {
        Get_Maopi();
        while(!key1);
    }
    if(key2 == 0)
        Delay(10);
    if(key2 == 0)
    {
        Weight_Maopi = 0;
        while(!key2);
    }
}

3.源代码

#include
#include 

/*I/O口声明*/
sbit LCD1602_RS = P3^5;
sbit LCD1602_RW = P3^6;
sbit LCD1602_EN = P3^4;
sbit HX711_DOUT = P2^1; 
sbit HX711_SCK = P2^0;
sbit key1 = P3^0;
sbit key2 = P3^1;

/*全局变量定义*/
unsigned long Weight_Shiwu = 0;
unsigned long Weight_Maopi = 0;

/*函数声明*/
void Delay(unsigned int n);
void Init_LCD1602();//LCD1602初始化函数
void LCD1602_write_com(unsigned char com);    //写指令
void LCD1602_write_word(unsigned char *s);    //写字符串
void LCD1602_write_data(unsigned char dat);    //写数据
unsigned long HX711_Read(void);
void Keyscan();
void Get_Maopi();
void Get_Weight();

int main()
{ 
    Init_LCD1602();        //LCD1602初始化
    LCD1602_write_com(0x80);        //移动光标到第一行首位
    LCD1602_write_word(" Dian Zi Cheng! ");        //显示 Dian Zi Cheng! 
    LCD1602_write_com(0x80 + 0x40);            //移动光标到第二行首位
    LCD1602_write_word("Weight :"),            //显示Weight :
    Delay(1000);        //1s延时
    while(1)
    {
        Keyscan();
        Get_Weight();    
            
        LCD1602_write_com(0x80+0x49);        //移动光标到第二行第九位
        LCD1602_write_data(Weight_Shiwu%10000/1000 + 0X30);        
        LCD1602_write_data(Weight_Shiwu%1000/100 + 0X30);
        LCD1602_write_data(Weight_Shiwu%100/10 + 0X30);
        LCD1602_write_data(Weight_Shiwu%10 + 0X30);
        LCD1602_write_word(" g");
    }
    return 0;
}

/*称实物重*/
void Get_Weight()
{
    Weight_Shiwu = HX711_Read();  
    Weight_Shiwu = Weight_Shiwu - Weight_Maopi;
    Weight_Shiwu = (unsigned int)((float)Weight_Shiwu/429.5);    
}

/*延时子函数*/
void Delay(unsigned int n)
{
    int i, j;
    for(i=0; i

4.功能演示

（二）.LCD_1602显示重量及计算价钱（单价可以按键调节）

源代码如下

#include
#include 

/*I/O口声明*/
sbit LCD1602_RS = P3^5;
sbit LCD1602_RW = P3^6;
sbit LCD1602_EN = P3^4;
sbit HX711_DOUT = P2^1; 
sbit HX711_SCK = P2^0;
sbit key1 = P3^0;
sbit key2 = P3^1;
sbit key3 = P3^2;
sbit key4 = P3^3;
sbit Flag_ERROR = P2^3;

/*全局变量定义*/
unsigned long Weight_Shiwu = 0;
unsigned long Weight_Maopi = 0;
unsigned int price = 1;
unsigned long all = 0;
/*函数声明*/
void Delay(unsigned int n);
void Init_LCD1602();//LCD1602初始化函数
void LCD1602_write_com(unsigned char com);    //写指令
void LCD1602_write_word(unsigned char *s);    //写字符串
void LCD1602_write_data(unsigned char dat);    //写数据
unsigned long HX711_Read(void);
void Keyscan();
void Get_Maopi();
void Get_Weight();
void All_Price();
int main()
{ 
    Init_LCD1602();        //LCD1602初始化
    LCD1602_write_com(0x80);//移动光标到第一行首位
    LCD1602_write_word(" Dian Zi Cheng! ");    //显示 Dian Zi Cheng! 
    LCD1602_write_com(0x80 + 0x40);            //移动光标到第二行首位
    LCD1602_write_word(" Welcom to use! ");    //显示Welcom to use!
    Delay(1000);        //1s延时
    LCD1602_write_com(0x01); //清屏

    LCD1602_write_com(0x80);//移动光标到第一行首位
    LCD1602_write_word("Weight :");//显示Weight :

    LCD1602_write_com(0x80 + 0x40);//移动光标到第二行首位
    LCD1602_write_word("p:");//显示price :

    

    

    //Delay(1000);        //1s延时
    while(1)
    {
        Keyscan();
        Get_Weight();
        All_Price();
        if(Weight_Shiwu > 5000)        //超重报警
        {
            Flag_ERROR = 0;      //报警
            LCD1602_write_com(0x80+0x09);
            LCD1602_write_word("ERROR!");    
        }
        else
        {
            Flag_ERROR = 1;//关闭蜂鸣器        
            LCD1602_write_com(0x80+0x09);//移动光标到第1行第九位
            LCD1602_write_data(Weight_Shiwu%10000/1000 + 0X30);        
            LCD1602_write_data(Weight_Shiwu%1000/100 + 0X30);
            LCD1602_write_data(Weight_Shiwu%100/10 + 0X30);
            LCD1602_write_data(Weight_Shiwu%10 + 0X30);
            LCD1602_write_word(" g");

            LCD1602_write_com(0x80+0x43);        //移动光标到第二行第3位
            LCD1602_write_data(price/10 + 0X30);
            LCD1602_write_data(price%10 + 0X30);
            LCD1602_write_word("Y");
            
            LCD1602_write_com(0x80+0x47);        //移动光标到第二行第7位
            LCD1602_write_word("All:");//显示All_price :
            LCD1602_write_data(all%1000/100 + 0X30);
            LCD1602_write_data(all%100/10 + 0X30);
            LCD1602_write_data(all%10 + 0X30);
            LCD1602_write_word("Y");        
        }
    }
        
    return 0;
}


//计算价钱
void All_Price()
{    
    
    all = price *Weight_Shiwu; 
}


/*称实物重*/
void Get_Weight()
{
    Weight_Shiwu = HX711_Read();  
    Weight_Shiwu = Weight_Shiwu - Weight_Maopi;
    Weight_Shiwu = (unsigned int)((float)Weight_Shiwu/429.5);
        
}

/*延时子函数*/
void Delay(unsigned int n)
{
    int i, j;
    for(i=0; i

功能演示

四.多功能电子秤显示日历时间及闹钟设置

注：此内容详见专栏“51单片机”中《万年历》代码详解

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