their robot controller with another Power Point show, which
illustrated the following four tests:
1. Make sure all the solders looked good. This meant
solders formed shiny cones that did not overflow
2. Use the DMM to verify there was no continuity
between the power and ground terminals of the
3. Use the DMM to check that proper voltage existed
between the power and ground pins of the PICAXE
IC socket. The proper voltage was stated as being
between 4. 75 and 5. 25 volts.
4. After inserting the PICAXE-08M2, program it with a
simple debug program to test that two-way
communication existed between the PICAXE and
Before assembling the robot body, we gave students
two programming assignments. First, they programmed
their robot controller to increment a variable. This showed
them how to program their robot controller count to 255.
The second assignment was to make an LED blink. They
then adjusted the length of the PAUSE command and
observed its affect on the LED’s rate of blinking.
Making a Robot body
and navigating Using
After creating their first programs, students began
building their robot body. Again, we lead them through the
construction with a Power Point presentation. After
constructing the robot body, students mounted their robot
controller to it. To drive the robot, we showed class
members how HIGH and LOW commands controlled the
spinning of the robot’s wheels. Since the robot had two
driven wheels and tail dragger, students learned to make
their robot travel forward, backwards, turn left, turn right,
and stop by controlling which direction each wheel turned.
We did not teach our students to use pulse width
modulation as a means to control the speed of each wheel.
After demonstrating that they could program their
38 SERVO 12.2013
A student's first solder. One of the mentors is stabilizing his PCB.
We determined that our families needed eight skills to
complete a robot. There wasn’t enough time for them to
become experts in all eight skills, considering the limited
amount of class time available. Our goal, therefore,
became to make them somewhat familiar with the
following eight skills.
• Soldering components to a printed circuit board
• Using a digital multimeter to test electronic circuits.
• Identifying popular electronic components by sight.
• Interpreting popular electronic schematics.
• Reading resistor and capacitor values.
• Mechanically assembling a robot body.
• Programming a robot to reach a goal using BASIC.
• Incorporating feedback in a robot program to guide
a robot’s behavior.