Ability to modify USB_TYPE in Teensy.md

See #313

HISTORY.md

@@ -18,7 +18,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - New: Add support for installation using homebrew(https://github.com/ladislas)
 - New: Add support and example for flashing on a remote RPi. (https://github.com/Gaboose)
 
-- Tweak: Update Malefile-example.mk with STD flags (https://github.com/ladislas)
+- Tweak: Update Makefile-example.mk with STD flags (https://github.com/ladislas)
 - Tweak: Allow remove of any OBJDIR with `$(REMOVE) $(OBJDIR)`. (https://github.com/ladislas)
 - Tweak: Add cpp to extensions supported by "make generate_assembly". (https://github.com/sej7278)
 - Tweak: Update travis-ci to test against Arduino 1.0.6. (https://github.com/sej7278)
@@ -27,6 +27,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Tweak: Moved location of avrdude for 1.5.8 on Linux (Issue #301) (https://github.com/sej7278)
 - Tweak: Allow 'build.core' param as found in [arduino-tiny](https://code.google.com/p/arduino-tiny/) Prospective Boards.txt. (https://github.com/Gaboose)
 - Tweak: Replace CXX_NAME with CXX as per the Emacs Flymake Wiki (Issue #309) (https://github.com/sej7278)
+- Tweak: Ability to override `USB_TYPE` in Teensy.md (Issue #313) (https://github.com/Poofjunior)
 
 - Fix: Improved Windows (Cygwin/MSYS) support (https://github.com/PeterMosmans)
 - Fix: Change "tinyladi" username to "ladislas" in HISTORY.md. (https://github.com/ladislas)

Teensy.mk

@@ -135,8 +135,12 @@ endif
 
 ########################################################################
 # FLAGS
+ifndef USB_TYPE
+    USB_TYPE = USB_SERIAL
+endif
+
+CPPFLAGS += -DLAYOUT_US_ENGLISH -D$(USB_TYPE)
 
-CPPFLAGS += -DLAYOUT_US_ENGLISH -DUSB_SERIAL
 CPPFLAGS += $(call PARSE_TEENSY,$(BOARD_TAG),build.option)
 
 CXXFLAGS += $(call PARSE_TEENSY,$(BOARD_TAG),build.cppoption)

arduino-mk-vars.md

@@ -452,6 +452,32 @@ VARIANT = leonardo
 
 ----
 
+### USB_TYPE
+
+**Description:**
+
+Define Teensy 3.1 usb device type. Default is USB_SERIAL
+
+**Example:**
+
+```Makefile
+USB_TYPE = USB_SERIAL
+# or
+USB_TYPE = USB_HID
+# or
+USB_TYPE = USB_SERIAL_HID
+# or
+USB_TYPE = USB_MIDI
+# or
+USB_TYPE = USB_RAWHID
+# or
+USB_TYPE = USB_FLIGHTSIM
+```
+
+**Requirement:** *Optional*
+
+----
+
 ### USB_VID
 
 **Description:**