Using a VEX Controller
By Daniel Ramirez
VEX Robotics Design
System Projects
Twenty-first century scientists, engineers, mathematicians, and medical
researchers need the mathematical, analytical, problem-solving, and science
skills that can be developed by engaging in creative robotics projects and
contests in the same way that engineers of the early 20th century used
mechanical construction kits (such as the popular Gilbert Erector Set and
Meccano Erector Set) to expand their knowledge. It is no surprise that
students in high school who participated in robotics contests show dramatic
improvement in their math and science skills.
One area that has been neglected over the years is the electronics field that once helped to make the US the leader in electronics, computers, and consumer devices such as telephones, TVs, and
radios in the 20th century. Now that lead has dramatically
eroded due in part to globalization but also due to the lack
of course curriculum provided by public and private schools
in the US. Electronics courses are generally not available to
secondary and high school students.
About the only exposure to electrical theory is in
Physics classes. It’s really at the college or university level
that students can study electronics if they choose. Most
students who learn electronics from an early age are either
self-taught or have parents in the electronic field that
provide assistance to them. Other resources include DIY
electronics projects published in magazines such as
Nuts & Volts and SERVO Magazine.
The VEX construction system (which is similar to the
Gilbert and Meccano erector sets) is now widely used by
both elementary and high school level students who
compete regularly in national comptetions like the VEX
Robotics Contest and FIRST. These contests have brought
together international students from Canada, China,
Mexico, Brazil, and other countries from around the world.
The VEX microcontroller provides the motor control and
48 SERVO 08.2010
also provides feedback from various sensors including
bumper switches, limit switches, sonar rangers, IR rangers,
and quadrature optical encoders for VEX-based robots. One
only has to go to the VEX forum ( www.vexforum.com)
and the VEX Gallery ( www.vexforum.com/gallery/
index.php) to see the hundreds of models featured. Other
independent VEX forums exist such as www.vexfan.com,
which I highly recommend since they also have many
models as examples.
The VEX microcontroller is the “silicon brain” that
makes an excellent, low cost learning platform that can be
used for carrying out both analog and digital electronic
experiments, as well as ones for science, robotics, and
animatronics (as I have tried to demonstrate in the last
three articles). It can be used with the original VEX starter
kit, the Vexplorer kit, and additional new kits that IFI now
sells. These include educational classroom bundles, along
with various robot accessories and contest props.
The VEX Keypad Experiment
In this article, I will show you how to develop a user
interface for the VEX microcontroller using the DIY LCD