#include <LiquidCrystal_I2C.h>
#define ldr A0
#define red 4
#define blue 2
#define green 3
int data;
LiquidCrystal_I2C lcd(0x27,16,2);
 
  {
digitalWrite(red ,r);
digitalWrite(green ,g);
digitalWrite(blue,b);
  }
void setup() 
{
pinMode(green, OUTPUT);
pinMode(red, OUTPUT);
pinMode(blue, OUTPUT);
 Serial.begin(9600);
  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0);
  lcd.print("ldr data:");

}

void loop() 
{
  data=analogRead(ldr);
  lcd.setCursor(10,0);
  lcd.println(data);
  data = map(data,0,1023,0,3);
  if(data==0)
 RGB (1 , 0  , 0)
  else if (data==1)
   RGB (0 , 1  , 0)
  else if(data==2)
      RGB (0 , 0  , 1)
      void RGB (int r , int g  , int b)
      {
        digitalRead(red,r);
        digitalRead(green,g);
        digitalRead(blue,b);
      }
 delay(1000);
}