#define L1 13
int adcValue;

void setup()
 {
Serial.begin(9600);
pinMode(A3, INPUT);
pinMode(L1, OUTPUT);  
}

void loop() 
{
adcValue=analogRead(A3);
Serial.println("Nilai ADC:");  
Serial.println(adcValue);

if(adcValue>=500)
{
  digitalWrite(L1, HIGH);
}
else
{
  digitalWrite(L1, LOW);
}
delay(2000);
}