PROJECTS: MAKEY ROBOT
5. CONNECT AND TEST THE DRIVE MOTORS
The contact tabs on our inexpensive motors are fragile, so their connections must be strong and
5a. Remove the motors and Arduino board from the robot body.
5b. Cut 2 red and 2 black 12" leads out of the stranded wire and strip 1" off an end of each. Without
soldering, wrap each red/black pair around the round back end of the motor (for strain relief), then run
the wires along the top and stick them on with a sandwich of double-stick foam tape. Don’t cover any of
the holes in the motor body, and leave room for the mounting nuts.
5c. Thread and solder the capacitor leads through the holes in
each motor’s connector tabs. This requires innovative bending
with needlenose pliers. Then solder the motor wires to the capacitor leads, not the motor connectors, making a strong joint. Clip
the extra lead length. Then cover the capacitor and the wrapped-around wires with black tape, and use more foam tape to cover
the pointy bits.
5d. Twist the free ends of the motor wire pairs together; this also reduces noise on the circuit. Mark the
motors as Left and Right.
5e. Solder and heat-shrink short solid-core jumper wires to the drive motor and battery snap leads
(this lets you plug them into the breadboard). Route the motor wires through the big holes in the plastic
5f. Plug the motor driver over the central trench of the breadboard and wire it to the drive motors and
one battery, following the schematic. (Recall that on each side of the trench, holes in the same row are
connected.) Use short jumpers to keep the wires close to the breadboard, as big loopy wires won’t fit
inside the robot.
5g. Download and install the Arduino software from arduino.cc
and download the 5 project test programs from makezine.com/
19/makey. Hook the Arduino to your computer via USB, and if
it’s a Diecimila, move its power jumper to USB.
5h. To test the motors, run the program 01_Test_Motor_Rotation. The left motor should run forward and back,
followed by the right motor. If not, check your wiring. Next, run 02_Test_Motor_Speed. The motors should
start slow, speed up, and then reverse direction. Otherwise check wiring to pins D11 and D3.
84 Make: Volume 19