Asynchronous fireflies use few parts

led-firefly

[Karl Lunt] wrote in to share his LED firefly project. His goals for the project were to develop a low-power, low parts count module that can sense when it's dark and then mimic the blinking patterns you'd associate with its biological namesake. We like his design which uses a coin cell battery holder as the chassis for the project. The ATtiny13 driving the hardware is held in place by the two … [Read more...]

Wireless doorbell battery monitor

wireless-doorbell-battery-monitor

We know exactly what [Dan] is going through. We also bought a cheap wireless doorbell and are plagued by the batteries running down. When that happens, the only way you know is when people start pounding on the door because you're not answering the bell. Well no more for [Dan]. He built a backup system which monitors the voltage of the batteries on the chime unit. You can see the small bit of … [Read more...]

RF switching module can learn new remotes

rf-remote-also-learns-by-itself

This breadboarded circuit is [Sergio's] solution to controlling appliances wirelessly. Specifically he wanted a way to turn his pool pump on and off from inside the house. Since he had most of the parts on hand he decided to build a solution himself. What he ended up with is an RF base station that can learn to take commands from different remote devices. The main components include the solid … [Read more...]

ATTannenbaum

attiny

It's that special time of year again where the smell of baking cookies fill the house and shopping mall parking lots are filled with idiots and very angry people. [Kevin] thought it would be a good idea to build an LED Christmas tree and ended up building a great looking tree that's also very simple. In the video, the imgur album, and the github, [Kevin] shows us the simplest way to make a … [Read more...]

Programming a microcontroller one bit at a time

xkcd

Imagine you're stuck on a desert island, hundreds of miles away from the nearest person, and you finally have time to finish that project you're working on. You have a single microcontroller, but you're lacking a computer and you need to program an ATtiny13. How do you do it? [androidruberoid] figured out how to manually flash a microcontroller (Russian, surprisingly good translation) using … [Read more...]

Turning on PC speakers whenever there is music playing

stereo

If you're like a lot of people, most of the time your computer speakers are on without actually playing any music. This wastes a bit of power, and [Bogdan] thought he could create a circuit to cut down on that wasted electricity. The result is a very tiny auto-on circuit able fit inside a pair of speakers. The circuit is built around the ATtiny13, very nearly the smallest microcontroller … [Read more...]

Toorcamp: Quadcopter Controlled By a TI-84+

Blue TILP

What happens when you combine a TI-84+ graphing calculator with an added bluetooth module, a 1 Watt Alfa wifi dongle, and a Parrot Wifi Quadcopter? You get a long range quadcopter that's controlled from the TI-84+ directional pad. This TI-84+ looks like a standard issue school calculator, but [Owen] added an ATTiny13 microcontroller and a bluetooth module which sniffs the I/O port of the … [Read more...]