74 SERVO 08.2015
Fortunately, there’s an easy solution, but it’s one you’ll
want to have in mind when doing your shopping in the first
place — get a motor driver. You could rig up some H-bridges
on a breadboard if you wanted to MacGyver it, but the
easiest way to go would be to get a motor shield for your
board.
The great thing about boards like the Uno is that they
have a lot of expandable shields for additional functionality.
The motor shield will only run you around $10 or so, so the
additional part won’t break the bank. Just be sure to order
one in the first place, or you might be left with a Runt as
helpless as Wallace without Gromit.
That was actually the precise situation we were in —
we failed to get a motor driver when we got our Uno. So,
our Runts would just have to share the DFRobotShop Rover
Duemilanove-based board.
Programming can be as puzzling as the mysteries best
left to Hercule Poirot
and his trusty
sidekick, Arthur
Hastings. We often
seem to run afoul of
problems getting the
bot and the computer
to talk to each other,
or ensuring that we
have all of the
required code
libraries, or some
other unclassifiable
issue that stymies our
efforts. We have
never had those
problems, however,
while using Arduino
boards. The forum
and support for Arduino is really fantastic, with plenty of
pages of sample programs that are always annotated with
links to any other required libraries.
The Arduino site also does a fantastic job of walking
you through the steps of getting your board set up,
including the critical steps of getting the board and
computer talking in the first place. There are only two main
stumbling blocks that pop up: You have to be sure you
identify your board correctly; and you have to identify your
COM port correctly.
The Duemilanove is one of the older Arduino boards,
and you need to be sure to download the required drivers
from the FTDI site. You’ll know if you have the drivers
already by whether or not the proper COM port appears as
an option in the relevant drop-down menu.
We started with some programs from the Arduino
sample library, including one that allowed us to control the
bot with our computer keyboard through the serial monitor.
It was fun to see the Bogie spring to life and start tackling
NOW WITH MORE CLAWS.
NOW WITH MORE CODE.
NOW WITH MORE LIMES. TAKE THE LIME AND RUN.
