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
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