Servo - March 2008

Reviving an

Androbot BOB

PART 2

by Robert Doerr

Last month, you read about how I started re-using

some leftover robotics components to revive an old

Androbot BOB robot chassis. I focused on what was

needed to control the drive motors in the BOB base. I

also covered upgrades to an old Handy Board controller

to make it more suitable for use on a larger robot and enhancements to the board to make it more reliable. Since

the only thing I had to start with was the empty robot shell

and drive motors, this entire project is covering the rest of the parts that are needed to build a functional autonomous robot. If it weren’t

for the re-use of the body shell and drive assembly, this series would basically cover building a

whole new robot from scratch. During the process, I’ll try to illustrate how each phase was going

to work out, how plans change along the way, and the resulting changes that were done to accommodate those changes to make it all work.

One goal of this project was to re-use as much existing stuff as possible and to give leftover parts a purpose. I felt it appropriate to use recycled components, too. When building some “one off” projects and hand wired PCBs, I like to try and re-use old parts that may have otherwise ended up in a landfill.

Some of the parts you’ll see this time came from some unlikely places. In particular, some of the relays used on the board to multiplex the sonar sensors came from old Token Ring network cards that were being thrown out. The small LEDs used on that same board came from an old ADIC tape library controller board that also was heading out to the dumpster.

This is a great use of parts when prototyping. For projects that will need more than a couple of like boards, I would go

ahead and layout a new PCB instead of hand wiring them all on a proto board. I’d also make sure that any parts used are ones that are readily available.

How is all this stuff going to end up in BOB?

driver for the main drive motors, the custom power board, the Polaroid Sonar ranger, and a Sonar MUX board. There will also be a few other boards which will be covered in the next article.

The best place to mount everything

As stated in the first article, anything that is going in the robot is simply going to bolt-in or plug into the existing chassis and electronics. No alterations to the original robot are going to be done. This is one of the first issues to overcome. Where and how am I going to mount all this new stuff in BOB? To start, there is the main Handy Board controller, the H-bridge