       Serial.println( msgIn );
       rcvdNum = (int)msgIn.substring(1 + msgIn.indexOf(' ')).toInt();
       msgIn = "";
+      txFlag = true; //Set up to transmit response after RX
     }else{
       msgIn += lastChar;
     }

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10) Serial.print('0');
  Serial.print(digits);
}
  sentenceRdy = false;
  sentence[0] = 0;
  sentenceIndex = 0;
  //txTimer.begin(transmit, 10000000);
  pinMode(5,INPUT_PULLUP);
  while( !Serial1 );
  while( !Serial2 );
