Fixed $MONITOR_PORT detection, thanks choffmann

Arduino.mk

@@ -879,7 +879,7 @@ ifeq ($(CURRENT_OS), WINDOWS)
     DEVICE_PATH = /dev/ttyS$(shell awk 'BEGIN{ print $(COM_PORT_ID) - 1 }')
 endif
 
-ifdef ARDUINO_PORT
+ifdef MONITOR_PORT
     DEVICE_PATH = $(MONITOR_PORT)
 else
     # If no port is specified, try to guess it from wildcards.

HISTORY.md

@@ -13,6 +13,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Fix: Add missing newlines at end of some echo's (Issue #207) (https://github.com/sej7278)
 - Fix: Add missing/reorder/reword targets in `make help` (https://github.com/sej7278)
 - New: Arduino.mk is now compatible with Flymake mode (https://github.com/rbarzic)
+- Fix: MONITOR_PORT detection (Issue #213) (https://github.com/sej7278)
 
 ### 1.3.3 (2014-04-12)
 - Fix: Make a new manpage for ard-reset-arduino. Fixes issue #188 (https://github.com/sej7278)