Reader [Mike] was not too impressed by design in a recent post we did on an LED menorahs. Doing what any self respecting hacker would do, he designed and built a better one then sent it in to us. He just happened to have an AVR ATtiny13 sitting around, so he used that for the brains. It has single button operation, is powered by 2 AA batteries, and even simulates the candles burning out. His custom PCB turned out quite nicely as well, the power plug connects to the batteries in a way that uses them as a base. Check out his site for detailed plans and source code. Great job [Mike].
LED Hacks1892 Articles
Meggy Jr RGB Portable Game Platform

Evil Mad Scientist Laboratories have just announced the release of the Meggy Jr RGB, a fully programmable handheld console with an 8×8 RGB LED matrix display. Like its big sisters Peggy and Peggy 2.0, the Meggy Jr is driven by an ATmega168 microcontroller and is made up of a bank of fully addressable LEDs. Unlike its siblings, the device boasts six buttons and the ability to be mounted inside of a custom case (or “handle set”) constructed from plastic or wood, drastically altering the look of the console. Using the popular open-souce Arduino environment, users are able to write custom software for the device. While it works great as a game console, of the many possible configurations and suggested uses, we think “disco floor for your Lego minifigurines” is the most amusing.
Weasure, A Scale That Weighs And Measures

[John Peterson] created this postal scale device for a Renesas design contest. The Weasure not only calculates the package’s total weight but the dimensions as well. He built it using a SKP16C62P evaluation board that had an LCD, pushbuttons, and indicator LEDs. The original DigiWeigh parcel scale was modified to provide PWM output and tare control. He embedded photoresistors every inch along each axis. They were angle slightly upward and the surroundings were painted black to minimize reflection. The Weasure outputs everything via a serial connection so it can be used with shipping software to generate postage.
LED Menorahs
We’re barely past Halloween and people are already working on their next LED based holiday decorations. For Hanukkah, Gizmodo pointed out the PCB menorah pictured above. It uses a set of DIP switches to control which LEDs are lit. A couple years ago, Evil Mad Scientist Laboratories put together a tutorial for building a more minimal LED menorah. Each of the nine LEDs are soldered directly to the legs of an ATtiny2313 microcontroller. Every time you power up the device an additional LED is lit. [Ori] liked the project and decided to take a slightly different approach. He used an LM3914 DIP18 LED bar driver. A potentiometer controls how many of the LEDs are illuminated.
Minimalist LED Light Detecting Candle
[youtube=http://www.youtube.com/watch?v=sPe5RtUOOdc]
Our flickering LED circuit combined two known circuit, and certainly wasn’t graceful because of it. [sprite_tm] saw quite a few areas where the circuit could be reduced. He ended up taking it down to just two LEDs, a battery, and an ATtiny13. The first step was getting rid of the current limiting resistors. The datasheet shows that with a 3V supply the AVR will limit the current well below the maximum current. The light sensor was removed next. [sprite_tm] referenced an earlier post on sensing with LEDs. He measures the voltage across one of the LEDs while it is off to see how much light is hitting it. The current draw while on is 10mA and 50uA while off.
Multi-Color Fog Spreader

Though we’re pretty sure this was meant for Halloween, we think it would be a perfect addition to your election night party. [marc92] shows us how he built a fog spreader with red or blue lighting. Fog machines generally spit out the fog from a single point, relying on the breeze to spread it around. [marc92] wanted it spread a little more evenly, as well as some nice mood lighting. He built a pipe system that would emit fog from a much larger area. Mounted on the pipe are red and blue LEDs. Mix this with some of the election lighting systems and you’re set for a party. We know this is an extremely simple project, so it should give you plenty of time to get out and vote before the polls close.
Colorize Your Election Party

[Eric] has put together a simple python script to scrape election results from CNN.com. It uses urllib2 to return the popular and electoral votes for each party and throws an ElectionWon exception when CNN calls the race. He’s planning on hooking this to DMX controlled RGB LED lighting that will shift to either blue or red as the night progresses. It’s a great starting point if you want to pull off something similar.
You may remember [Eric] for building the IKEA MAME table and the TRS-80 wireless terminal.
[photo: skenmy]
UPDATE: [Garrett] of macetech is putting the finishing touches on his version which uses 32 ShiftBrite modules and 2 4-digit displays controlled by a CuBLOC.

