const int pin_lux_0     = A1;
const int ADC_AVG_RES   = 4;

void setup() {
  analogReadAveraging(ADC_AVG_RES);
  Serial.begin(115200);
  pinMode(pin_lux_0, INPUT);
}

void loop() {
  int l = analogRead(pin_lux_0);
  Serial.println(l);
  delay(50);
}