F EATURE
ARTICLE
by Steve Lubbers (USA)
KartTracker A GPS-Based Vehicle Timing & Monitoring System The KartTracker is a standalone GPS-based vehicle timing system. The LCD on the system’s development board operates as the user interface, an integrated accelerometer records G forces, a serial port provides connections to a GPS receiver and a wireless transmitter, and removable flash memory stores data.
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n a variety of racing activities, time is of the essence! It is useful to both know and record information such as lap times, top speeds, and best lap times. At a more personal level, the questions are “Did John really win again?” and “Am I racing any better than I was last year?” In any type of race (i.e., cycling, running, or motor vehicle), you want to know who is fastest. Outside of the race, timing information is important to help determine if training, testing, and adjusting are making you better or worse. In the fall of 2010, Renesas announced the RX MCU Design Contest. Contestants were asked “What can you do with…?” and were tasked to bring their ideas and designs to reality. This challenge gave me a golden opportunity to showcase my talents and prototype a timing system to use for kart racing (see Photo 1). Next time we visit the track, we will know who is quickest!
Most of the pieces of my KartTracker are already built into the Renesas Electronics RX62N development board (see Figure 1). The liquid crystal display (LCD) on the development board operates as the user interface and shows the driver what is happening as he races. The integrated accelerometer can be used to record the G forces experienced while racing. A serial port provides connections to a GPS receiver and a wireless transmitter. Removable flash memory stores all the race data so you can brag to your friends. You now have all of the pieces of my KartTracker.
February 2012 – Issue 259
THEORY OF OPERATION
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I decided on a standalone device to time my racing activities. This would enable operation anytime and anywhere for any type of activity. Since small global positioning system (GPS) receivers have become inexpensive enough to appear in cars, watches, and pet collars, I investigated their use for my project. I figured if Jill Garmin can direct me—“Please drive the highlighted route”—perhaps her third cousin Bubba can help my racing! A GPS-linked device appeared to be the perfect solution to my problem.
Photo 1—Karts provide the neighborhood NASCAR fans with an inexpensive way to experience racing. Always on the lookout for another engineering project, I wondered how I could add a computer system to this adventure. CIRCUIT CELLAR®
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