Coding4Fun

Building the Hardware

The first step in this project is to get the remote-control car connected to the computer in some manner. The easiest way to do this is to directly wire the handheld control unit to the Phidget Interface Kit, which plugs into the computer's USB port. The key to this step is finding a remote-controlled car that has a "digital" controller. That is, the joysticks, when moved, simply close a switch. A remote-controlled car with "analog" inputs will allow the user to vary the speed and turn the wheels, which certainly adds increased control, but also adds a fair amount of complexity to the project as well as expense for hardware to properly control it. In my experience, the cheaper the car, the more likely it is to have digital inputs. Additionally, cars with remote controllers that contain buttons instead of joysticks are almost always digital input devices.

The car used in this chapter is from the Dub City collection by Jada Toys, and costs about $20 (see Figure 8-3). If that particular car is not available to you, be sure to check out the book's website at http://www.c4fbook.com/ to see what other models people have successfully used with this project.

If you plan on using more than one remote-controlled car at a time for racing, ensure that you purchase cars that run on different radio frequencies. The box will usually be marked with either the frequency or a letter denoting a frequency, such as A/B/C. If you buy multiple cars with different frequencies (or letters), ...