Have it all installed and mostly working, my PSU does not like 3.3v logic. Got the fire pin hooked up with a simple pullup, but intensity is still not getting set properly. Tried making a simple level shifter with parts I had on hand, but that failed. Gonna order up a
level shifter and
voltage translator from sparkfun to see if one of those will do the trick.
Smoothieware is pretty awesome though, and the folks on #smoothieware irc channel are very helpful.