==== P2N2222AG ====
  * http://4.bp.blogspot.com/-rxS57z6Xfaw/TdoS2zXjA8I/AAAAAAAAA_I/1D8nVfbqkZM/s1600/P2N2222A+Pinning.png
  * emitter == GND

==== IR333C (IR LED) ====
  * longer leg = + (anode)
  * http://wyxs.net/web/wiimote/digital_whiteboard/symbol_led.jpg