   lastAOA = AOA;
 #ifdef SHOW_SERIAL_DEBUG    
   // show serial debug info.
-  sprintf(tempBuf, "AOA:%i Live:%i ASI:%ikts ALT:%i PPS:%f cycleCounterResetAt: %i",AOA, liveAOA, ASI, ALT, pps, cycleCounterResetAt);
+  sprintf(tempBuf, "TONE AOA:%i Live:%i ASI:%ikts ALT:%i PPS:%f cycleCounterResetAt: %i",AOA, liveAOA, ASI, ALT, pps, cycleCounterResetAt);
   Serial.println(tempBuf);
 #endif
 }


#ifdef SHOW_SERIAL_DEBUG    
  // show serial debug info for skyview data found.
  sprintf(tempBuf, "SKYVIEW AOA:%i Live:%i ASI:%ikts ALT:%i PPS:%f cycleCounterResetAt: %i",AOA, liveAOA, ASI, ALT, pps, cycleCounterResetAt);
  Serial.println(tempBuf);
#endif
          validAOADataFound();  // run function to process tone.  because we found a valid AOA value.
          

  #define LOW_TONE_PPS_MIN      1.5
  #define LOW_TONE_HZ           400     // freq of low tone
  #define BAUDRATE_EFIS         115200  // default baud rate for D100/D10
#endif
#endif


#define TONE_PIN              2     // TIOA0
#define PIN_LED1              13    // internal LED for showing AOA status.
