1) changed in R0.2 -- silkscreen font is really small
2) changed in R0.2 -- add breakout holes for all unused pins to simplify CS routing
3) changed in R0.2 -- add 'Power' LED
4) changed in R0.2 -- add two MAX232 chips (four VR stimulation channels)
5) changed in R0.2 -- merge 5v's
6) changed in R0.2 -- add ECU power LED
7) todo:              reduce width to 10cm/3.93701 inches