PROJECTS: BAJA BUGGY
4d. Before installing the wireless camera to the camera servo, shorten the
camera’s cable and solder another
2-pin male connector so it will plug into
the motor-control circuit board at J3.
To do this, cut the camera’s cable down
to about 3". Strip 1" of insulation and
slide on a 2" piece of heat-shrink tubing. Then solder the black and red wires
to the 2-pin connector, slide the heat-shrink tubing over the connection, and
shrink it with a heat gun or hair dryer.
4e. Using your double-sided tape,
attach the wireless camera to the
camera servo temporarily (you’ll
adjust it later).
5. INSTALL THE MOTOR BATTERY
AND PROGRAM THE PIC MICROCONTROLLER
5a. For the motor’s power source, you need something that will supply enough voltage and last a while between
charges. I used a Thunder Power lithium polymer (Li-Poly) 1,320mAh/7.4V 2-cell rechargeable battery.
I don’t recommend using less than a 480mAh/7.4V battery, as it would need to be recharged more often.
CAUTION: The battery will have a charge even if you buy it brand-new, so keep the 2 wires from touching!
5b. Strip the black and red wires coming off the battery. Solder the wires
to another 2-pin male connector, and
heat-shrink. Attach the battery to the
9V battery holder with double-sided
tape, and connect the rechargeable’s
wires to J5 (VBAT) on the circuit board.
5c. To program the PIC MCU, I used a PICkit 2 Starter Kit (#DV164120) that I bought from my company,
Microchip Technology ( microchipdirect.com) for $50. This kit has everything you need to write, debug, and
program your source code directly into the MCU via header J2 on the circuit board. (If you’re a student or
educator, visit microchip.com/academic to learn how you can get a discount on development tools through
Microchip’s Academic Program.) Go to makezine.com/14/bajabuggy. All you have to do is to import the
carprogorig.hex program file using the PICkit 2 Starter Kit interface, and then click the Program button.
104 Make: Volume 14
NOW GO USE IT »