Paul yeah the rainy season has started in Ireland. It will probably last well into june 2010! I'm happy enough with the params right now but its great to know they can be altered. Motor i have in the car is compound wound so will probably need some tweaking. I'm thinking of wiring the shunt field in parallel with the series field/armature for testing. Then i'll try a seperate shunt power supply. Do you reckon i'll have a problem with the esr of the bus caps? I have 2x 3900uf 400v and 2x 1500uf 400v in parallel.
Mike the software you need is called ponyprog and you can make a little header circuit to talk to the micro via the icsp port.
AVR Programmer
PonyProg - Serial device programmer