ATTiny85 read IR remote codes
- based on http://nathan.chantrell.net/20121014/tinypcremote-an-attiny85-based-infrared-pc-remote-control/
- original code https://github.com/nathanchantrell/TinyPCRemote
- NEC format referred from http://www.sbprojects.com/knowledge/ir/nec.php
- Only works for NEC pulse with encoding.