| Forgot your front door key again? With this door opener, all you need in the future is some musical talent to get into your apartment. This...
Jörg Trautmann (10)
| Small and dirt-cheap ultrasonic sensors enable us to design measuring devices for all kinds of ranging. Take one of these modules, add a dis...
| Although only a small circuit, this smart alarm detects when your refrigerator door is open and lets you observe the internal temperature on...
| This installment: - Door alarm mod detects water
| Although some people don’t seem to mind revealing their innermost thoughts online, we know from recent revelations about the NSA activities...
| Small, widely available and dirt-cheap ultrasonic sensors enable us to design both simple and lavish measuring devices for all kinds of rang...
| This little project was inspired by a tilt sensor circuit which first appeared in our 2010 Special Projects Edition. The idea was to build a...
| There are now many different types of LED candle simulators available. Before we begin to design a more realistic candle with a wind-noise d...
| Current consumption is always an important consideration when designing battery-powered devices. This circuit shows how a seven-segment disp...
| It is widely thought that light can be therapeutic for the human skin and soul. Light at the correct wavelength may also be effective agains...