diff -r e5254c6aa0c8 -r 01515349b30e src/hp34comm.cpp
--- a/src/hp34comm.cpp	Tue Oct 11 00:46:18 2016 +0200
+++ b/src/hp34comm.cpp	Tue Oct 11 21:44:04 2016 +0200
@@ -16,7 +16,7 @@
 
 DigitalOut lled(LED1);
   
-HPSerial::HPSerial(PinName rx, PinName tx):
+HPSerial::HPSerial(PinName rx):
   serial_rx(NC, rx),
   ncmd(0) {