Nuts and Volts - July 2014

by Bryan Bergeron, Editor by Bryan Bergeron, Editor

DEVELOPING

It’s summer time and — especially if you've been cooped up all winter — time for outdoor activities. Because electronics experimentation is traditionally conducted indoors on a benchtop, you may put your hobby aside until after summer vacation. However, it needn't be the case. I'm not suggesting that you duplicate Benjamin Franklin's experimentation with kites and lightning, but there's plenty to do outdoors. For example, if you're into sports and training, there are any number of circuits you can build and then perfect outside — from timers for track and force sensing plates for impact sports, to radar guns for baseball.

If you're into drones and flying, then there are dozens of drone kits and hundreds of model airplanes and helicopters that you can build and modify — from adding a GPS system to an onboard video camera. My current favorite in miniature cameras is the GoPro series, especially if you're within range of a Wi-Fi hot spot. The remote control unit is easily duplicated, allowing you to design a control system that fits your particular needs. For GPS, there are several sub-$100 units available from SparkFun and other sources.

Don't forget that water and electronics often mix well.

Whether you're installing a wireless water alarm system for your basement or to detect a stopped-up storm gutter, there's plenty you can do to improve your home. Last summer, I installed a weather station — complete with the usual detectors. For a twist, I added a Geiger-Muller tube and alarm to detect and notify me of an increase in the ambient radiation level. So far, I haven't detected any peaks in radiation.

If you're into tanning — or avoiding skin cancer — then consider an ultraviolet level/timer. It'll tell you when to flip over or when it's time to reapply your sunblock, depending on your goals. For supplies, consider an inexpensive UV filter made from a pair of sunglasses and a UV detector made from an inexpensive photodetector.

Alternatively, consider an analog UV detector breakout board from SparkFun ($12). You'll also need your favorite microcontroller to process the analog signal and provide a suitable alarm.

As a final suggestion, consider repurposing or processing the signals from one of the popular physiological monitors on the market. For example, there's the Polar heart rate monitor interface also available from SparkFun ($60). Together with a microcontroller, you can develop any number of training routines for yourself or others. You'll need to program your maximum heart rate for your age, target value, and other parameters that you can look up in any good training manual. You might consider teaming up with a personal trainer if your knowledge of physiology isn't up to your abilities in electronics.