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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
This month marks four years of Mr. Roboto for me. Much has changed since I started. For one thing, there are more robot controller options out there that have a lot of power and aren't very expensive;
for example, the Digilent chipKIT series and Raspberry Pi to
name just two. There are new platforms like Robot OS
(ROS) and new "glue" programs like RoboRealm. Pololu and
SparkFun are carrying newer and better motor and servo
controllers, and IMU (Inertial Measurement Unit) devices
have become affordable to the robot hobbyist for aircraft
and walking robots.
Robo-One style walking robot events have unseated
mini Sumo as the totally cool robot competition to
compete in. If you haven't seen the movie “Real Steel” yet,
do so; I believe we are only a few years away from that
level of full-sized humanoid robot competition. In my
opinion, our only hold-up is the self-contained power
system required to just get a walking robot to move!
It has been exciting and fun. Here's to even better
times ahead! Hackers and hobbyists, if you have questions,
suggestions, and even examples to share with us, please
let me know and I'll help and/or publicize it. I just love this
hobby!
Q. Hey Mr. Roboto! It’s Corey, again. I have to say, I’m liking the articles following my question! The PS controller was actually something I had
been looking into, so I was very glad to see you write
about it.
I actually have another product question for you. I
promise this one will be much simpler than the chipKIT
one.
There seems to be a lot of articles talking about
controlling motors in robots using the tinyESC by
Finger Tech Robotics. Although I have yet to personally use
this, I would absolutely love to! The only thing that has
12 SERVO 02.2013
First off, I have to apologize that my "reach exceeded
my grasp" this month, and I was unable to complete the
project required to get an Arduino to control the Roomba
robot. I had issues with timing between the Arduino and
the Roomba that I could not explain. At first, I was
convinced that the Roomba was a 3.3V serial interface
that was not reliable when connected to the 5V Arduino
UART. However, Roomba documentation clearly states that
the serial connection is a 5V UART. So, that idea didn't fly.
I am working out these details now.
There were also some reports that the Arduino library
for the Roomba was not robust enough, but I'm not
convinced that it isn't the interface causing the problem,
instead of the library. Finally, my nemesis -- the CABLE --
got in my way a bit as I sorted through the connectors to
attach to the Arduino board. Grr. Some projects just don't
work out according to plan!
Regardless, I will beat this project into submission and
I WILL HAVE A WORKING SETUP next month. In the
meantime, I'll answer some questions that I had postponed
while working on this Roomba problem.
On with the questions!
kept me from buying any of these is the price since they
are $35 a pop. In browsing the HobbyKing’s site, I noticed
that they had a bunch of ESCs (electronic speed
controller), and that they are really cheap (as in $6-$15 for
the 20A and below models). Could you do a comparison
of these cheaper ESCs to the infamous tinyESC? I know all
of the spec differences between them, but I want to know
how they differ in real working situations. If they stack up
nicely functionality-wise compared to the tinyESCs, I would
love to buy five of the $6 ESCs for the price of one
tinyESC! Thanks!
— Corey Hastings
