Chuck Fellows for president! Great work Chuck, I'm sure you have inspired hundreds of code newbies, me included. I purchased a SainSmart clone on Aliexpress, I found it was giving pushbutton errors quite often and I checked the voltage divider resistor values and 3 of them were wrong. The biggest error was that the top-most resistor was 3k instead of 2k. Big improvement in stability now. I'm thinking there might should be some decoupling caps on the shield Vcc? The stock board apparently has none. Mark S.