I just started playing around with one of these Arduino boards a few weeks ago for measuring strain on bow limbs and material test samples. They are incredibly capable devices and very inexpensive. It is funny because I was looking for a decent distance measuring sensor to use with the Arduino to measure draw force curves, and I happen to see your post with this video. Cool!
It would take a little programming, but the device could be much more automated, along with generation of various stats like total stored energy, stored energy to pounds draw, etc. There are even blue-tooth add-one that you could use to beam the results to your phone.
Thanks for sharing this
Alan