THIS
MONTH:
Getting
Serial
THE MARK III ROBOT FROM PARTS.
Even casual readers of SERVO have probably picked up on one of our major pet peeves when it comes to robotics kits: RS-232 serial ports. We can tolerate a little
nostalgia as well as anyone, but the frequency with which
we see RS-232 ports on robot kits is baffling. Robotics
tinkerers are generally high tech people with high tech
gadgets, and we can’t remember the last time we saw a
relatively new laptop with an RS-232 port on it. Roboticists
like us are forced to invest in a serial-to-USB adapter which
may not be a big expense, but it certainly seems like an
unnecessary inconvenience.
Back in the July ‘09 issue of SERVO, we dedicated an
article to unraveling the mystery of RS-232 port persistence.
CONNECTORS AND MORE, FOR MODS GALORE!
As part of the article, we wanted to convert one of our
numerous serial equipped kits with a USB connection. Our
plans were foiled when we received the wrong part in the
mail, so instead we took a more academic approach — even
interviewing one of Evan’s professors from UCSD. The
results of our investigation were clear: There was really no
good reason for robotics kits to cling to serial ports like dust
to a Swiffer. Even so, we’ve still been haunted by our
unfinished business of actually converting a robot kit from a
serial to USB connection.
Thus, we arrive at the present article. SERVO readers
may also be acquainted with the Mark III robot kit from
Junun Robotics, as it has made several appearances in Twin
Tweaks over the last few months. We
found an FTDI adapter through Digi-Key
that we could use to convert the RS-232
equipped bot to a much more current
USB connection. With this part on the
way, we could finally answer the last
remaining question in our crusade
against RS-232 ports: For tinkerers fed
up with using adapters, is converting a
robotics kit to a USB connection a
practical endeavor?
Mark My Words
The Mark III is a compact little
robot kit that uses a PIC microcontroller
as its main brain. As its name suggests,
the general-purpose robot evolved from
two previous incarnations — both of
70 SERVO 09.2011