#define LED  9
int data;
float v;
void setup() 
{
  Serial.begin(9600);
  pinMode(LED, OUTPUT);
}
void loop() 
{
  data = analogRead(A0);
  v = (data / 1023.0) * 5 ;
  Serial.print("Vin = ");
  Serial.print(v);
  Serial.print("[V]");
  Serial.print(", data = ");
  Serial.print(data);
  Serial.print(", = ");
  Serial.println(data, BIN);
  if (data > 409)
    digitalWrite(LED, 1);
   else
    digitalWrite(LED, 0);
   delay(1000);
}