Intro To Charlieplexing

December 3, 2008 by Caleb Kraft 4 Comments

charlie

[sixerdoodle] sent us this nice firefly project that serves as an intro to charlieplexing. We’ve mentioned charlieplexing before, in our LED Life post and the Breath Controlled LED candles post. This project is quite simple and focues mainly on how to make a charlieplexed circuit work.

The goal was to create a tiny firefly bottle with SMD LEDs and as few wires as possible. In the video, after the break, it is hard to tell just how small this thing is until we see the battery. There are clear directions and fantastic pictures detailing exactly how to set up a charlieplexed circuit with 6 LEDs.

Continue reading “Intro To Charlieplexing” →

Jar Of Fireflies

October 18, 2008 by Eliot 14 Comments

[Randomskk] has been attempting to make electronic fireflies for quite some time and finally settled on a design he liked. His jar of fireflies uses an ATtiny13 to control a set of 12 matrixed LEDs. The green SMD LEDs are each soldered to a pair of thin wires that hang down into the jar. The software picks an LED at random to flash and then flashes it 1-3 times. The random seed is incremented each time the jar is turned on, so you’ll get 255 different patterns. The power is just a standard coin cell. The project is fairly simple electrically, but the LED soldering could prove difficult. It was inspired by this firefly jar project. Check out [Alex]’s synchronizing fireflies too. A video of the jar is available below. Continue reading “Jar Of Fireflies” →

LED Random Blinking Mood Lighting

September 15, 2008 by Caleb Kraft 7 Comments

What is it about pseudo random flashing LEDs that make us go gaga? We don’t know, but there’s definitely something there. [seligtobiason] has this obsession too. After seeing several more complicated projects, he created this elegant, simple, and cheap piece of art. The entire thing is pretty much just some flashing LEDs, some resistors, and a power supply. It really isn’t anything groundbreaking, but the effort and cost involved are tiny compared to some other similar projects. sure, it doesn’t synchronize over time based on input like the firefly project. But for a quick cheap project, the results are quite nice.

We would put one in our home, right next to the node blinky.

Synchronizing Fireflies NG

July 28, 2008 by Eliot 9 Comments

[Alex] from Tinkerlog has revisited an old project with Synchronizing Fireflies NG. Fascinated by how fireflies blink at same rate and synchronize with each other, he built a digital version. Each board has an RGB LED and a phototransistor or photoresistor. A ping-pong ball is used as a diffuser. The blink rate is controlled by an ATtiny13v. The board power can be daisy chained, but each firefly mote operates independently of the others. The microcontroller has a fixed flash rate and monitors for other flashes. It attempts to sync by flashing earlier. The color of the LED expresses how satisfied the firefly is with its current sync. You can see a video of eight fireflies attempting to self organize embedded below.