iOS Sensor Apps with Arduino

Listening for Messages on the Arduino

Open up the Arduino development environment, enter the following code, and upload it to your Arduino board (if you’re unsure how to do that, have a look at Chapters 1 and 2 again):

#define LENGTH 2

int rxBuffer[128];
int rxIndex  = 0;

void setup() {

  Serial.begin(9600);
  Serial.println("Arduino reset");

  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);

  digitalWrite( 12, HIGH);
  digitalWrite( 13, HIGH);
  delay(500);
  digitalWrite( 12, LOW );
  digitalWrite( 13, LOW );
}

void loop (){

 if (Serial.available() > 0) {

   rxBuffer[rxIndex++] = Serial.read();
   if (rxIndex == LENGTH) {

       Serial.print( "Set: " );
       Serial.print( rxBuffer[0], DEC );
       Serial.print( " to: " );
       Serial.println( rxBuffer[1], DEC );

       if( rxBuffer[1] == 0 ) {
         digitalWrite((int)rxBuffer[0], LOW);
       } else {
         digitalWrite((int)rxBuffer[0], HIGH);
       }
       rxIndex = 0;
   }
 }
 delay(10);

}

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