One of our goals at Circuit Cellar is to bring you a variety of projects—from the serious and complex to the lighthearted and fun. Each teaches valuable techniques that you can use in your own real-world applications. You can replicate the projects you read about, or you can apply the techniques in a new way to suit your own needs. We also look for fascinating emerging technologies that we think can benefit you. This month, we’ve included a little bit of everything.

We start with a bit of levity. It’s almost summer, and that means barbecue. For an ordinary person, that might mean rolling out the gas grill from the garage to grill hot dogs and hamburgers. But, for an engineer, it means a project. John Moyer used his engineering prowess to design a sophisticated grill that’s sure to make him the envy of every other guy in the neighborhood (p. 28). Rather than use the average Weber or George Foreman grill, he opted for a unique ceramic cooker. As any die-hard barbecue fan knows, slow cooking meat to get that perfect barbecue flavor takes days. Most people just don’t have that kind of time to tend the fire. So, John designed an automatic temperature controller to tend the fire for him. With a microprocessor, thermocouple, and some other parts, he’s now able to prepare beef brisket the way it should be done, and not get fired for leaving work to check the meat.

Why be content with a purchase when you know you can make it better? And, how about testing that product to see what you’ve actually bought? When you look at factory specs, you might wonder how accurate they are. Did the manufacturer fudge the numbers at all? Are they attainable only under a precise set of optimum circumstances? With an accelerometer from Analog Devices and a PIC microcontroller, Ross Tsukashima set out to test the limits of his new car (p. 24). As is often the case, the testing equipment available off the shelf wasn’t an option, so he built his own G-force meter specially designed to meet his goals. You’ll want to read on to find out if his New Beetle lives up to its reputation.

We think you’ll be equally interested in reading about Zoltan Molnar’s Bluetooth application (p. 44). With the trend toward wireless firmly in place, Bluetooth is gaining popularity. Zoltan focused on a specific mode of connectivity—using only HCI interfaces. He created Blueport, an interface that enables you to connect simple embedded systems to the complex Bluetooth protocol stack. Despite having limited resources and no external RAM, you can achieve this type of wireless connectivity with a creative solution. That’s great news for engineers working primarily with 8-bit microcontrollers.

jennifer.huber@circuitcellar.com

Published: May 2003