The electronics for the mobile bar are fairly simple using off-the-shelf items. The entire robot runs off a 12 volt, 35 amp-hour SLA battery. The radio controller/receiver is a six channel Futaba
model tuned for ground frequency use. This was purchased from The Robot MarketPlace
A pair of Victor 883 Speed Controllers
is used to control the drive motors on BaR2D2 and are set up for "tank-style" steering. Note - for ease of driving, we set the transmitter up to use one stick to control the drive (mixing function). Follow the instructions included with the speed controllers for installation and setup. These were mounted on a piece of Sintra.
I reused the wiring harnesses and plugs from the wheelchair to provide wiring from the battery, to a main switch and to the motors. This allows you to easily unplug everything for transport. The switches and wire were purchased at Radio Shack
At this point, limit switches were on the beer turntable. They are wired in conjunction with the beer elevator and beer loading door so that: A) Anytime the elevator is up, the turntable can't spin, B) When the elevator goes back down, the turntable is allowed to rotate until the next beer hits a limit switch, C) The turntable and elevator can't spin with the loading door open, D) A manual three-way switch allows for loading/off/dispensing of the beers. See diagram below. Zip-ties were used to secure the wiring.