Merge pull request MHeironimus#7 from MHeironimus/add-ide-checking

Added additional compiler directives to check for the proper version of the Arduino IDE and compatible device.

Author: MHeironimus

Joystick/Joystick.h

@@ -23,6 +23,14 @@
 
 #include "HID.h"
 
+#if ARDUINO < 10606
+#error The Joystick library requires Arduino IDE 1.6.6 or greater. Please update your IDE.
+#endif
+
+#if !defined(USBCON)
+#error The Joystick library can only be used with a USB MCU (e.g. Arduino Leonardo, Arduino Micro, etc.).
+#endif
+
 #if !defined(_USING_HID)
 
 #warning "Using legacy HID core (non pluggable)"

Joystick2/Joystick2.h

@@ -23,6 +23,14 @@
 
 #include "HID.h"
 
+#if ARDUINO < 10606
+#error The Joystick2 library requires Arduino IDE 1.6.6 or greater. Please update your IDE.
+#endif
+
+#if !defined(USBCON)
+#error The Joystick2 library can only be used with a USB MCU (e.g. Arduino Leonardo, Arduino Micro, etc.).
+#endif
+
 #if !defined(_USING_HID)
 
 #warning "Using legacy HID core (non pluggable)"

Joystick3/Joystick3.h

@@ -23,6 +23,14 @@
 
 #include "HID.h"
 
+#if ARDUINO < 10606
+#error The Joystick3 library requires Arduino IDE 1.6.6 or greater. Please update your IDE.
+#endif
+
+#if !defined(USBCON)
+#error The Joystick3 library can only be used with a USB MCU (e.g. Arduino Leonardo, Arduino Micro, etc.).
+#endif
+
 #if !defined(_USING_HID)
 
 #warning "Using legacy HID core (non pluggable)"