// Arduino_LDR_5

#include <LiquidCrystal_I2C.h>

#define LED_GREEN 2
#define LED_YELLOW 3
#define LED_RED 4
#define LDR A0

#define I2C_ADDR    0x27
#define LCD_COLUMNS 16
#define LCD_LINES   2

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

void setup() {
  Serial.begin(9600);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  lcd.init();
  lcd.backlight();
}

int c = 0;
int value, percent;

void loop() {
  value = analogRead(LDR);
  value = (1024 - value);
  percent = map(value, 0, 1023, 0, 100);
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("#");
  lcd.print(++c);
  lcd.setCursor(0, 1);
  lcd.print("Light = ");
  lcd.print(percent);
  lcd.print("%");

  if (percent >= 66) {
    digitalWrite(LED_RED, HIGH);
  } else {
    if (percent >= 33) {
      digitalWrite(LED_YELLOW, HIGH);
    } else {
      digitalWrite(LED_GREEN, HIGH);
    }
  }
  delay(250);
  digitalWrite(LED_RED, LOW);  
  digitalWrite(LED_YELLOW, LOW);
  digitalWrite(LED_GREEN, LOW);
}