illumination_sensor (조도센서)

방에 불을 끄면 어두워서 --> led On

const int led_yellow_pin        = 13;
const int illumination_sensor = A0;
int value;
void setup() {
  // put your setup code here, to run once:
  pinMode(led_yellow_pin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  value = analogRead(illumination_sensor);
  Serial.println(value);
  if ( value < 100) {
    digitalWrite(led_yellow_pin, HIGH);
  } else {
    digitalWrite(led_yellow_pin, LOW);
  }
 }