Over the last decade, the open-source movement has not only transformed the world of software, but also catalyzed a sweeping revolution in hardware tinkering. At the heart of this shift lies a ...

Using motion detectors and an Arduino you can trigger lights, fans, or even an pneumatically controlled cleaver-wielding clown to help add your house to the “if you dare” list.

That resulting signal is a square wave, which is an easy target for the Arduino to measure. That timing measured from the square wave can then be used to calculate the inductor’s value.

While newer Arduinos and Arduino compatibles (including the Hackaday.io Trinket Pro. Superliminal Advertising!) either have a chip capable of USB or rely on a V-USB implementation, the old fogies o… ...