LDR Sensor Module

// Canonical beginner example for an LDR Sensor Module
// Reads the analog light level and prints it to Serial.

const int ldrPin = A0;

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ; // Needed for some boards; safe on Uno as well
  }

  Serial.println("LDR Sensor Module example");
  Serial.println("Reading analog light level from A0...");
}

void loop() {
  int lightValue = analogRead(ldrPin);

  Serial.print("Light level: ");
  Serial.print(lightValue);
  Serial.println(" / 1023");

  delay(500);
}