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Tap into the sum of allhumanknowledge and get your questions answered here!
From software algorithms to material selection, Mr. Roboto strives to meet you
where you are — and what more would you expect from a complex service droid?
by
Dennis Clark
By this time, I will know if my two pound critter has
done well in the MileHiCon Critter Crunch or if it has
embarrassed itself (and me for that matter.) The Critter
Crunch has been running for more years than I care to
remember and was the first of the “Battle Bots” type of
competitions to happen. We’ve never called them robots
though, just critters since these machines were typically
remote controlled. However, for the last few years I have
been encouraging fully autonomous critters to come and
play. (Soon, soon, humans will be obsolete in the Critter
Crunch! Bwa ha ha ha! Ahem.) I’ll let you know next
month how it came out.
By next month, maybe my house won’t be full of sick
kids and adults too. The flu season hit early this year.
Regardless, on to the questions. I got a few this month that
will be taking a bit more time to research and complete.
Here are the ones that I could fit into the writing schedule.
There were some interesting questions again this month.
First, here are a couple of robot club announcements from
those that have sent me info about their groups.
Robot Clubs:
The Saskatoon Combat Robotics Club (SCRC) is located
in Saskatoon, Saskatchewan, Canada and holds combat
events every few months.
Our local combat robotics club’s website is www.
kilobots.com and our forum is http://forums.
delphiforums.com/saskatooncrc
— Kurtis
I am a member of an Australian amateur robotic
engineering group called Robot SIG. We are based in
Brisbane, Australia and meet once a month at the Nathan
Campus of Griffith University. Our website is www.
robotsig.org/ but it is currently out of date (soon to be
updated). We have an active forum at http://maxwell.
me.gu.edu.au/bw/RobotSIG-Forum/
We deal with autonymous types of robotics. We
14 SERVO 11.2009
recently had our first public showing at the Griffith
University Open Day and were well received.
— Nigel
Q. I came into possession of a couple of Dinsmore
1490 compasses and I’m wondering just how I can
use these. They are WAY cheaper than the other
compass boards out there, so it seems a good use of my
time to make a cheap compass for my robot! Can you tell
me how?
— Dean
A. These compasses are still being called the Dinsmore
compass even though Dinsmore doesn’t appear to
make them anymore. A company named The Robson
Company, Inc., is making them now ( www.robsonco
. com/Dinsmore/).
At $15 US, they are a good deal for an inexpensive
compass. Google for the Dinsmore 1490 and you’ll find a
few robot companies out there selling them. The 1490 is
a VERY highly damped mechanical compass with four
Hall-effect sensors in it. It is a little slow and you want to
keep it level, but it works just fine. The 1490 is a digital
sensor that can give you eight compass headings, not much
resolution, but hey, it’s inexpensive, right? I can hear you
asking “But wait, there are only four sensors, how do I get
eight compass directions?” Easy — you will get two sensors
triggering when the direction falls in the middle between
two of the major axis. You’ll be able to detect N, NE, E, SE,
S, SW, W, and NW. The Dinsmore 1490 is a bit of a power
hog, so I like to turn it off when I’m not using it.
Since I like to use distributed computing when I can
rather than load down a single processor with all of the
work, I wrote a little program to run in a PIC12F508 to
handle the compass controls and decoding, and provide a
simple serial interface to get the data. Originally, this
interface was for a Parallax BASIC Stamp II board, but it will
work with any processor you want as long as you can work
up an asynchronous serial connection. The program outputs
