Twin Tweaks ...
STARTING FROM SCRATCH WITH A NEW BOARD.
COMPARING THE SERIAL DB9 CONNECTOR AND THE FTDI ADAPTER.
WE SWITCHED FROM RS-232 TO USB AND SAVED A
TON OF HASSLE WITH ADAPTERS!
72 SERVO 09.2011
been wary about soldering ICs directly to PCBs —
desoldering every pin from a dual inline package
can be a real test of patience if you ever want to
make a change. In case we ever wanted to
switch out any of the components, we used
sockets for the DIPs that were soldered to the
board instead of the ICs themselves. The sockets
were still low profile enough to allow the
addition of mezzanine boards without incident.
Our socket mania reached more than just
the ICs. We also added sockets for the Sharp
sensors which would normally solder directly into
the front of the PCB. This would make things
easier if we ever wanted to build a new board
for the Mark III — no desoldering, just
unsocketing. The additional sockets were pretty
low profile and did not interfere with the
compact frame of the robot. The sockets also
made it easier to route the wires for the sensors
while avoiding some of the stress relief problems
that attend direct joints with the PCB.
As mentioned previously, one of the main
reasons our dad was initially drawn to the Mark
III as an exciting platform for experimentation
was the prospect of using it as a way to become
familiar with OOPic. The Mark III is compatible
with an OOPic microcontroller that could
effortlessly replace the original PIC because they
both fit into the socket we used while originally
building up the board. The Mark III is a great
way to experiment with object-oriented
programming because it comes with sensors (like
the Sharp infrared sensors) that can be turned to
classic tasks like line following.
The dual servo motor drive is also ideal for
simple dead-reckoning programs. The
prototyping and sensor mezzanine boards are a
great way for robotics experimenters with limited
time to tackle discrete projects that still reward
the successful tinkerer with a sense of
accomplishment. You could add a bumper style
touch sensor so that the bot could wall-crawl
around a maze Roomba style. You could add
more infrared sensors to the front of the robot
to improve its line following or opponent finding
ability. Discrete projects like this are perfect for
folks like our dad — someone who hasn’t had as
much time to focus on robotics projects since
FIRST Team 1079 stopped pulling all-nighters in
Robot Central (check out the September through
December ‘04 issues for more on those glory
days of yore).
Even with only limited time to devote to the
Mark III, our dad has turned the bot into a
scrappy competitor that has made several
appearances in Twin Tweaks over the years.
Whether it’s smoking the Ollo bugs in a lopsided