Thanks for the info, CrossRoads. It is indeed the standard smoke detector-type square 9V battery. I looked up the info on Wikipedia; a standard AA battery supplies something around 400 to 900 mAh, whereas the one 9V only has 565 mAh (according to Wikipedia). So as you said, putting three together gives me (~400*3) mAh which is plenty more power than the 9V. Does my logic sound right? If so, I guess it's back to Radio Shack to see if they have something like that! One question though, should I be using Vin or 5V when running on external power on the Uno? The docs seem to suggest Vin is the way to go.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16