 #define FLAG_GPS_FIX 0b00000001
 #define FLAG_PAYLOAD 0b00000010
 
+//directives received from ground station
 //make sure these match on the sending end
-#define FLAG_PAYLOAD 0xAB
-
-#define PIN_PAYLOAD 13
+#define DIR_TEST 0xAB
+#define DIR_PAYLOAD 0xACDIR_TEST
+
+#define PIN_TEST 13
 
 //Payload variables
 #define MAX_BUF 16  // Maximum payload size 


void setup()
{
  pinMode(PIN_PAYLOAD, OUTPUT);
  
  //Make sure Serial baud matches hardware config
  Serial1.begin(57600); //XBee baud rate

  if (Serial1.available()) {
    byte receivedPayload = Serial1.read();
    switch (receivedPayload) {
      case DIR_TEST:
        if ( digitalRead(PIN_TEST) == HIGH )
          digitalWrite(PIN_TEST,LOW);
        else digitalWrite(PIN_TEST,HIGH);
        break;
      default:
        digitalWrite(PIN_TEST,LOW);
        break;
    }
    #ifdef readDebug
