#include <LiquidCrystal_I2C.h>
#include<Wire.h>

LiquidCrystal_I2C lcd(0x27,20,4);

const int R1=12,R2=11,R3=10,R4=9;
const int C1=7,C2=6,C3=5,C4=4;

void setup() {
Serial.begin(115200);
lcd.init();
lid.backlight();
pinMode(R1, OUTPUT);
pinMode(R2, OUTPUT);
pinMode(R3, OUTPUT);
pinMode(R4, OUTPUT);
pinMode(C1, INPUT_PULLUP);
pinMode(C2, INPUT_PULLUP);
pinMode(C3, INPUT_PULLUP);
pinMode(C4, INPUT_PULLUP);
digitalWrite(C1, HIGH);
digitalWrite(C2, HIGH);
digitalWrite(C3, HIGH);
digitalWrite(C4, HIGH);
};



void loop(){
ROW1();
ROW2();
ROW3();
ROW4();
lcd.setCursor(0,0)
lid.print()
};

void ROW1(){
  //-------------------------ROW---------------------------
  digitalWrite(R1, LOW);
digitalWrite(R2, HIGH);
digitalWrite(R3, HIGH);
digitalWrite(R4, HIGH);
if (digitalRead(C1)==LOW){
  Serial.println("1");

  delay(200);
}
else if (digitalRead(C2)==LOW){
   Serial.println("2");
   delay(200);
}
else if (digitalRead(C3)==LOW){
   Serial.println("3");
   delay(200);
}
else if (digitalRead(C4)==LOW){
   Serial.println("A");
   delay(200);
};
 digitalWrite(R1, HIGH);
digitalWrite(R2, LOW);
digitalWrite(R3, HIGH);
digitalWrite(R4, HIGH);
if (digitalRead(C1)==LOW){
  Serial.println("4");
  delay(200);
}
};

void ROW2(){
digitalWrite(R1, HIGH);
digitalWrite(R2, LOW);
digitalWrite(R3, HIGH);
digitalWrite(R4, HIGH);
if (digitalRead(C1)==LOW){
  Serial.println("4");
  delay(200);
}
else if (digitalRead(C2)==LOW){
   Serial.println("5");
   delay(200);
}
else if (digitalRead(C3)==LOW){
   Serial.println("6");
   delay(200);
}
else if (digitalRead(C4)==LOW){
   Serial.println("B");
   delay(200);
}
}

void ROW3(){
 digitalWrite(R1,HIGH);
digitalWrite(R2, HIGH);
digitalWrite(R3,LOW);
digitalWrite(R4, HIGH);
if (digitalRead(C1)==LOW){
  Serial.println("7");
  delay(200);
}
else if (digitalRead(C2)==LOW){
   Serial.println("8");
   delay(200);
}
else if (digitalRead(C3)==LOW){
   Serial.println("9");
   delay(200);
}
else if (digitalRead(C4)==LOW){
   Serial.println("C");
   delay(200);
};
}

void ROW4(){
digitalWrite(R1, HIGH);
digitalWrite(R2, HIGH);
digitalWrite(R3, HIGH);
digitalWrite(R4, LOW);
if (digitalRead(C1)==LOW){
  Serial.println("*");
  delay(200);
}
else if (digitalRead(C2)==LOW){
   Serial.println("0");
   delay(200);
}
else if (digitalRead(C3)==LOW){
   Serial.println("#");
   delay(200);
}
else if (digitalRead(C4)==LOW){
   Serial.println("D");
   delay(200);
};
}