Time to start a Raspberry Pi discussion.
A customer came into the store today carrying a Raspberry Pi. Cute, looks like a Uno with some extra stuff. The USB was a Micro USB, and we found him the right cable. It's USB power requirements are 3/4 amp @ 5 volts, and the lore is to give it 1.0 amp. As USB 2.0 only guarantees about 0.5 amp, it took some serching to find him enough juice.
This Raspberry Pi is going to control (and sense) an 18 volt landscape irrigtion system.
My Raspberry Pi is on order, should be here in a few months.