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<reg52.h>
#include <intrins.h>/*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<n; i++)for(j=0; j<110; j++);
}//判断液晶忙，如果忙则等待
void Read_Busy()
{unsigned char busy;P0 = 0xff;LCD1602_RS = 0;LCD1602_RW = 1;do     //此语句先执行后判断{LCD1602_EN = 1;busy = P0;LCD1602_EN = 0;     //不使用时将EN拉低释放，以便于下次写数据的时候直接将EN置高}while(busy & 0x80);//判断P0的最高位是否为1，为1时忙碌（禁止），为0时不忙（允许发数据）//直到不忙时才跳出循环
}/*写指令*/
void LCD1602_write_com(unsigned char com)
{Read_Busy();//判断忙否LCD1602_RS = 0;Delay(10);LCD1602_RW = 0;    P0 = com;LCD1602_EN = 1;Delay(10);LCD1602_EN = 0;
}/*写数据*/
void LCD1602_write_data(unsigned char dat)
{Read_Busy();LCD1602_RS = 1;Delay(10);LCD1602_RW = 0;    P0 = dat;LCD1602_EN = 1;Delay(10);LCD1602_EN = 0;
}/*写连续字符（字符串）*/
void LCD1602_write_word(unsigned char *s)
{while(*s != '\0'){LCD1602_write_data(*s);s++;}
}/*初始化LCD1602*/
void Init_LCD1602()
{LCD1602_EN = 0;//LCD1602_RW = 0;LCD1602_write_com(0x38);LCD1602_write_com(0x0c);LCD1602_write_com(0x06);LCD1602_write_com(0x01);
}/*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); 
}/*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);}
}

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<reg52.h>
#include <intrins.h>/*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<n; i++)for(j=0; j<114; j++);
}//判断液晶忙，如果忙则等待
void Read_Busy()
{unsigned char busy;P0 = 0xff;LCD1602_RS = 0;LCD1602_RW = 1;do     //此语句先执行后判断{LCD1602_EN = 1;busy = P0;LCD1602_EN = 0;     //不使用时将EN拉低释放，以便于下次写数据的时候直接将EN置高}while(busy & 0x80);//判断P0的最高位是否为1，为1时忙碌（禁止），为0时不忙（允许发数据）//直到不忙时才跳出循环
}/*写指令*/
void LCD1602_write_com(unsigned char com)
{Read_Busy();//判断忙否LCD1602_RS = 0;Delay(10);LCD1602_RW = 0;    P0 = com;LCD1602_EN = 1;Delay(10);LCD1602_EN = 0;
}/*写数据*/
void LCD1602_write_data(unsigned char dat)
{Read_Busy();LCD1602_RS = 1;Delay(10);LCD1602_RW = 0;    P0 = dat;LCD1602_EN = 1;Delay(10);LCD1602_EN = 0;
}/*写连续字符（字符串）*/
void LCD1602_write_word(unsigned char *s)
{while(*s != '\0'){LCD1602_write_data(*s);s++;}
}/*初始化LCD1602*/
void Init_LCD1602()
{LCD1602_EN = 0;//LCD1602_RW = 0;LCD1602_write_com(0x38);//显示模式设置LCD1602_write_com(0x0c);//显示开及光标设置LCD1602_write_com(0x06);//显示光标移动设置LCD1602_write_com(0x01);//显示清屏
}/*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); 
}/*按键扫描*/
void Keyscan()
{if(key1 == 0){Delay(5);if(key1 == 0){while(!key1);Get_Maopi();            }}if(key2 == 0){Delay(5);if(key2 == 0){while(!key2);Weight_Maopi = 0;        }}if(key3 == 0){Delay(5);if(key3 == 0){price++;while(!key3);}}if(key4 == 0){Delay(5);if(key4 == 0){price--;while(!key4);}}
}

功能演示