Who hasn’t dreamed about owning their own metal detector and searching for buried treasure, or at least a few dropped coins? In this project, we will build a metal detector based on a dual oscillator circuit. One oscillator is fixed, and the other varies depending upon the proximity of metal objects. The beat frequency between […]
It all started with a small LCD salvaged from an old printer. I recruited my code-savvy older brother, Adam, and we soon had the LCD displaying text from an Arduino microcontroller. This was neat, but it was inconvenient having to plug the Arduino into a computer for reprogramming whenever we wanted to change the text. […]
By Christie, Jim, John, and Terry Noe Our dog, Maggie, loves to run around in our big yard. But how do we fence her in? Building a 500-foot fence is expensive and unsightly, so we use an “invisible fence.” This is a buried wire that runs around the edge of our yard. Maggie wears a […]
The Luna Mod is an easy and fun instrument that will have you making great-sounding loops in no time. Rather than sampling input like a traditional loop station, the Luna Mod synthesizes its own sounds, and you play it using two knobs and one button.
While reading through Charles Platt’s excellent book Make: Electronics, I came across this nice little circuit for making a gentle pulsing LED. I was struck by the “humanness” of the pulse, but couldn’t figure out what to do with it. Later I found a heart-shaped tag on some pants I had bought, and well, this […]
Whether you’re at a Bangkok hostel or backpacking in Goa, you can rock out to your favorite tunes with these portable Rock ’n’ Roll Speakers, a set of customizable, low-fi travel speakers that allow you to take your music everywhere. The speakers are driven by a simple power amplifier circuit and a tilt switch. With […]
I’m absentminded in general, but especially when it comes to the dishwasher. I can never remember whether the dishes are clean, whether the machine needs to be run, or emptied, or whatever. I needed a solution to this problem. My first thought was to hang a flippable sign on the door that said “clean” on […]
