//variable
int sensorPin = A0;
int sensorValue = 0;
 
void setup (){
 
  Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
  pinMode(9, OUTPUT); // initialize pin 9 as an output
 
}
 
  void loop(){
    sensorValue = analogRead(sensorPin); //read analog value from pin A0
    Serial.println (sensorValue); //Show the read result on log
    float voltage = sensorValue * (5.0/1023.0); //formula to calculate the voltage
    Serial.println(voltage); //show the voltage result on log
 
      if(voltage>=1){ 
        digitalWrite (9, HIGH);}
      else{
        digitalWrite(9, LOW);
      }
    delay(1000); 
}