利用薄膜键盘制作一个简易四则运算器

叁歲伎倆 2023-07-04 08:54 3阅读 0赞

薄膜键盘接2到9口

#include <Keypad.h> 
    const byte ROWS = 4; //four rows
    const byte COLS = 4; //three columns
    char passwd='1';
    char keys[ROWS][COLS] = { 
      { '/','#','0','.'},
      { '*','9','8','7'},
      { '-','6','5','4'},
      { '+','3','2','1'}
      };
      
    String firstNum = "";
    String secondNum = "";
    int demo=1;
    float result = 0.0;
    char operatr = ' ';
    byte rowPins[ROWS] = { 5, 4, 3, 2}; //连接到键盘的行插脚
    byte colPins[COLS] = { 9,8, 7, 6}; //连接到键盘的列插脚
    Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );//实例化Keypad 对象
    
    void setup(){ 
      Serial.begin(9600);
    }
    
    void loop(){ 
      Serial.println("简易四则运算器:");
      while(1)
      { 
        char key = keypad.getKey();//新建一个key 变量 用于获取键盘当前的值
        if(demo==1)
        { 
          if (key != NO_KEY && (key == '1' || key == '2' || key == '3' || key == '4' || key == '5' ||key == '.' || key == '6' || key == '7' || key == '8' || key == '9' || key == '0')) { 
            Serial.print(key);
            firstNum =firstNum +key;
           }
          else if(key != NO_KEY &&(key == '+' ||key == '-' ||key == '*' ||key == '/' ||key == '#'  ))
          {         
            Serial.print(key);
            operatr=key;
            demo=demo+1;
          }   
        }
        else
        { 
          if(key != NO_KEY && (key == '1' || key == '2' || key == '3' ||key == '.' || key == '4' || key == '5' || key == '6' || key == '7' || key == '8' || key == '9' || key == '0')) { 
          Serial.print(key);secondNum =secondNum +key;}
          else if(key != NO_KEY &&(key == '#' ))
          { 
            Serial.print("=");
            if(operatr=='+')
            { 
              result=firstNum.toFloat()+secondNum.toFloat();
            }
            else if(operatr=='-')
            { 
              result=firstNum.toFloat()-secondNum.toFloat();
            }
            else if(operatr=='*')
            { 
              result=firstNum.toFloat()*secondNum.toFloat();
            }
            else if(operatr=='/')
            { 
              result=firstNum.toFloat()/secondNum.toFloat();
            }
            Serial.print(result);
            demo=1;firstNum = "";secondNum = "";operatr = ' ';
            Serial.println("");
          }
        }
      }
    
    }