sensor.ino

int incomingByte = 0;   // for incoming serial data

// the setup function runs once when you press reset or power the board
void setup() {
	
  // initialize digital pin 7 as an output.
  pinMode(7, OUTPUT);
  
  // set up Serial library at 9600 bps
  Serial.begin(9600);           

}

// the loop function runs over and over again forever
void loop() {
   
  // send data only when you receive data:
  if (Serial.available() > 0) {
  	
                // read the incoming byte:
                incomingByte = Serial.read();

                // say what you got:
                Serial.print("I received: ");
                Serial.println(incomingByte, DEC);
                
                // if incomingByte == '3' ON
                
                if (incomingByte == 51){
                	Serial.println("ON");
                	digitalWrite(7, HIGH);   // turn the LED on (HIGH is the voltage level)
                }
                // if incomingByte == '4' OFF
                
                if (incomingByte == 52){
                	Serial.println("OFF");
                	digitalWrite(7, LOW);   // turn the LED on (HIGH is the voltage level)
                }
                
   }
   
  
  // read the input on analog pin 1:
  int sensorValue = analogRead(A1);
  // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
  float voltage = sensorValue * (5.0 / 1023.0);
  // print out the value you read:
  Serial.println(voltage);
  delay(1000);
}