#include <LiquidCrystal_I2C.h>
 
int b1 = 15;
int b4 = 2;
int b7 = 0;
int bclear = 4;
 
int b2 = 16;
int b5 = 17;
int b8 = 5;
int b0 = 18;
 
int b3 = 19;
int b6 = 33;
int b9 = 13;
int bistgleich = 12;
 
int bgeteilt = 14;
int bmal = 27;
int bminus = 26;
int bplus = 25;
 
LiquidCrystal_I2C LCD = LiquidCrystal_I2C(0x27,16,2);
 
void setup(){
  Serial.begin(115200);
 
  pinMode(b1, INPUT_PULLDOWN);
  pinMode(b4, INPUT_PULLDOWN);
  pinMode(b7, INPUT_PULLDOWN);
  pinMode(bclear, INPUT_PULLDOWN);
 
  pinMode(b2, INPUT_PULLDOWN);
  pinMode(b5, INPUT_PULLDOWN);
  pinMode(b8, INPUT_PULLDOWN);
  pinMode(b0, INPUT_PULLDOWN);
 
  pinMode(b3, INPUT_PULLDOWN);
  pinMode(b6, INPUT_PULLDOWN);
  pinMode(b9, INPUT_PULLDOWN);
  pinMode(bistgleich, INPUT_PULLDOWN);
 
  pinMode(bgeteilt, INPUT_PULLDOWN);
  pinMode(bmal, INPUT_PULLDOWN);
  pinMode(bminus, INPUT_PULLDOWN);
  pinMode(bplus, INPUT_PULLDOWN);
 
 
 
  LCD.init();
  LCD.backlight();
  LCD.setCursor(3,0);
  LCD.print("Calculator");
  delay(1000);
  LCD.init();
}
 
void loop(){
  if(digitalRead(b1)==HIGH){Serial.println("1");LCD.print("1");}
  if(digitalRead(b2)==HIGH){LCD.print("2");}
  if(digitalRead(b3)==HIGH){LCD.print("3");}
  if(digitalRead(b4)==HIGH){LCD.print("4");}
  if(digitalRead(b5)==HIGH){LCD.print("5");}
  if(digitalRead(b6)==HIGH){LCD.print("6");}
  if(digitalRead(b7)==HIGH){LCD.print("7");}
  if(digitalRead(b8)==HIGH){LCD.print("8");}
  if(digitalRead(b9)==HIGH){LCD.print("9");}
  if(digitalRead(b0)==HIGH){LCD.print("0");}
 
    if(digitalRead(bplus)==HIGH){
      
    }
 
 
  delay(400);
}