the opposite way. This is what causes the motor to
reverse directions. Refer to Figure 14 for how to wire
the switches on the control panel to the motors on the
1. Start first by connecting the battery holder to
the switches. Each switch needs power from
the batteries. Be sure not to cross up the red
(positive) and black (negative) connections
between the switches, or you might create a
2. Wire the switches as shown in blue. The crisscross of the wires is what makes the motor
3. Wire the switches to the motors using an eight
or 10 foot length of four-conductor modular
telephone extension. Clip off the modular plugs
on either end, and strip back about five inches
of the outer insulating jacket to expose the
wires inside. The wires are color coded — red,
black, green, and yellow (or orange) are common.
Solder the switch and motor connections as shown.
FIGURE 14. Wiring diagram for the BeginnerBot battery holder,
switches, and motors. The connection between the switches and
motors is through an eight to 10 foot length of four-conductor
modular telephone wire.
(On the control panel end, thread the wire through the
extra hole before soldering to the switches. This provides
added strain relief.)
Note: Telephone wiring is made to be very flexible which
is why it’s chosen here. Many kinds have a thin filament that
when soldered, burns away. It takes practice getting a good
solder job with this stuff, so take your time and try again if
your first attempt doesn’t turn out. If you continue to have
trouble, try a different brand of wiring, or substitute with
four-strand ribbon cable. The ribbon cable isn’t quite as
flexible, but it will do for our purposes. Avoid the use of solid
conductor wire. Important! The terminals on virtually all
DPDT switches provide for the wiring diagram as shown in
Figure 14. The switch has six terminals; two rows of three
terminals each. The “common” connections of the switch are
the two terminals in the middle.
If your switch came with a wiring diagram, check it to be
sure the two center terminals are common. If you have a
multimeter, dial it to test continuity, and apply one test lead
to a common terminal and the other lead to a terminal on
either side. Toggle the switch one way, then the other. In one
of the positions, the meter should show continuity.
Keep the telephone wiring from pulling out by making a
small coil around a 1/4” U-shaped plastic cable clamp. The
clamp acts as a strain relief. Use a clamp on both the control
panel and the robot base.
With the wires attached to the motors, fit the motors
into their gearboxes. The solder terminals should be oriented
so that they are not blocked by the body of the gearbox. The
motors “click” into place. The design of the gearbox allows
you to readily remove the motor — something we’ll do in a
later phase. The wiring of the finished BeginnerBot base and
control panel is shown in Figures 15 and 16, respectively.
FIGURE 15. View of the BeginnerBot base showing all the
wiring. This is actually the “top” of the robot for Phase 1.
FIGURE 16. Underside view of
the BeginnerBot control panel
showing all the wiring.
Operating the BeginnerBot
Review your handiwork to check for accidental shorts,
bad soldering joints, or other problems. When you are
satisfied all looks good, insert three AA batteries (standard