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<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#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<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

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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