ldr and lcd

// C++ code

//

#include <LiquidCrystal_I2C.h>

int ldr_light = 0;

int darkness = 0;

LiquidCrystal_I2C lcd_2(0x27, 16, 2);

void setup()

{

  lcd_2.init();

  lcd_2.clear();        

  lcd_2.backlight();

  pinMode(A0, INPUT);

  pinMode(7, OUTPUT);

  darkness = 650;

}

void loop()

{

  ldr_light = analogRead(A0);

  lcd_2.setCursor(1,0);

  lcd_2.print("Is it dark ?");

  lcd_2.setCursor(1,1);

  lcd_2.print("darkness=");

  lcd_2.print(ldr_light);

  if (ldr_light < darkness) {

    digitalWrite(7, HIGH);

  } else {

    digitalWrite(7, LOW);

  }

  delay(1000); // Wait for 1000 millisecond(s)

  lcd_2.clear();

}

https://www.build-electronic-circuits.com/arduino-light-sensor/