Micro pro as keyboard HID pause/break key

[johnwasser]

The USB key codes are in this document:
http://www.usb.org/developers/hidpage/Hut1_12v2.pdf

Looks like the key code you want is 76 (0x48). Add 136 to it to get it past the ASCII lookup:

#define KEY_PAUSE (76+136)
Keyboard.press(KEY_PAUSE);