Raghu, It's not as if I disagreed with Andy, quite the opposite as being an engineer I too think along Andy's lines - scope the problem, then divide and conquer. but I try to understand the hobbyist perspective since I was once a twelve year old trying to figure out microprocessors without having a clue. If I was overloaded at that stage with too much information I may have given up. If we can get James up and running with a micro and a/d outputting some values then he can do some experiments and better understand what he is trying to achieve so then he can ask better questions -like my a/d values are jittering +/- 10 counts - how do i fix this? and so on...

It's back to front thinking for an engineer.

Maybe we should point him towards a BASIC STAMP? I dare say there may be an experiment already done that approximates what James wants to do?