On Mon, 19 Aug 2013 23:34:46 +0100, The Natural Philosopher
wrote:

Maybe there are cheap ADCs with USB or serial outputs I could use.
This is getting interesting. Thanks for the idea.
Arduino has ADC at fairly low quality (8 bit I think)

Yes, that looks possible. Arduino nano has a 10-bit ADC with a sample
time of 100us. More than enough for this task I think. The only
poblen I can see is that the arduino doesn't have much storage so it
would need to log to something else.