end, test the center and outer sleeve of the connector.
The reading should show infinite ohms.
Secure the nine volt battery clip to the nine volt
battery. Use a small piece of double-sided foam tape to
mount the battery to the center of the bottom deck. The
tape should not be larger than about 1/4” square, so you
can readily peel the battery off when you need to replace
it. Figure 10 shows the mounting position for the battery
on the robot’s lower deck, between the two servo mounts.
Follow the diagram in Figure 11 to complete the
wiring of the four AA battery holder. Start by cutting off
3” from a 12” three-wire extension set (typically used to
extend the length of servo cables). Clip off the white wire,
and solder the red and black wires together as shown in
Figure 12. Apply heat shrink tubing to the soldered joints
to avoid shorts (refer again to Figure 12). Secure the holder
to the robot using small strips of Velcro™ or other hook-and-loop fastener. Apply the strips to the tops of the servos as
depicted in Figure 13, and mount the holder over the nine
volt battery. Insert fresh batteries into the four-cell holder.
Figure 14 shows the completed bottom deck of the
ArdBot II with motors, mounts, and wheels attached. Note:
I’m also showing the ArdBot II with the two front switches
already attached. You’ll do this part the next time.
Mark off the holes for the Arduino in the location
shown back in Figure 3. Drill the three holes using a 9/64”
bit. Secure the Arduino board to the top deck using 4-40
screws and standoffs. Important! If you use metal screws
to hold the Arduino, be sure to add plastic washers to avoid
any possible shorts. For convenience sake, you may wish to
opt for nylon screws. Mount the mini solderless breadboard
next to the Arduino. Most mini breadboards come with
double-sided self-adhesive tape. If yours doesn’t, you’ll need
to add your own.
To complete the ArdBot, secure the top deck to the
riser standoffs using 4-40 or 6/32” x 1/2” screws (or review
the sidebar on how to use long screws to make your own
Coming Up: Finishing Construction
and First Trial Run
That’s all the space we have for this first installment.
Next time, we’ll complete the electrical wiring, show how
to attach the batteries and servos to the ArdBot, and how
to do a simple test to make sure everything is working as it
should. We’ll then move on to programming the Arduino to
detect obstacles, control the robot remotely, sense when
it’s been picked up or moved, and lots more. SV
SERVO 08.2013 47