Overhauling LED Marquees

November 14, 2008 by Eliot 11 Comments

led-sign

In a previous job, [sprite_tm] was responsible for wrangling many different LED text ad marquees. The hardware was fairly simple and he always figured they could be pushed much further with a little work. He recently acquired ten 32×16 LED displays a decided to see what he could do with them. By the end of the project, he had full motion video running on the display. This is a great project to read up on if you’ve ever wondered about LED matrix displays. He starts by reverse engineering the electronics on the board. He then attached an ATmega88 to drive the display module. Multiple display modules were daisy chained together over serial. The article covers PWM control and refresh timing as well. Check out one of a few demo videos below. Continue reading “Overhauling LED Marquees” →

3D Printer Uses Office Paper

November 6, 2008 by Eliot 41 Comments

3dhouse
Mcor Technologies recently launched a brand new rapid prototyping machine. The Mcor Matrix forgoes the standard of expensive and rare build materials by using A4 office paper. The machine selectively deposits glue on the sheet of paper: more glue on the cross-section, less on the waste. It then uses a blade to cut out the part profile. The vertical resolution is determined by the paper thickness. You can use either 20lb paper, which has a thickness of .1mm, or 40lb, which is twice as thick, so it will build twice as fast. The final part can be sanded and painted like wood. The idea is similar to LOM, but those machines require specialized paper. It’s nice to see a company intentionally target a low cost of ownership. If they had used a laser though, you’d only have to worry about sourcing the glue. Machine and material prices have yet to be announced.

[via Fabbaloo]

Cellular Automata And LED Matrix Fun

October 28, 2008 by Caleb Kraft 7 Comments

Blinkomat, an LED matrix, turned out quite well. 240 LEDs controlled by an Atmega 16 is what we call a decent bookshelf decoration. The dimensions of 12×20 were chosen due to the fact that the microcontroller has 32 I/O lines. The LEDs are switched on and off using multiplexing. The brightness, controlled by pulse width modulation can be varied by 16 levels. The overall effect is quite smooth an fun to look at. He has programmed it to do other things than just cellular automata. Our personal favorite is a simple sine wave. Watch it after the break.

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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” →

SMD Soldering Practice Kit

August 24, 2008 by Eliot 9 Comments

Here’s an interesting kit put together just to help you work on your SMD soldering skills. It’s got 49 SMD LEDs on the front with a programming header and switch jumper. The back has an ATtiny26L and a coin cell. At only 3V, power management is essential; all of the example programs are only addressing one LED at a time (imperceptible to the human eye). If you turn on too many LEDs at the same time, the voltage drop could cause the AVR to reset. Included example programs are a scrolling marque, bouncing balls, and Conway’s game of life. SparkFun has tutorials for regular SMD soldering and using a reflow skillet. The video below shows the kit builder attaching just one LED using the heat and slide method.

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3x3x3 LED Cube

June 20, 2008 by Eliot 9 Comments

[portreathbeach] built this simple 3x3x3 LED matrix. It uses a PIC16F690 in a ZIF socket for the brains. Each layer has nine LEDs with the cathodes tied together. The anodes from each LED are connected to the LED below. The LEDs are multiplexed so that even though all layers appear to be on, they’re being addressed individually. He’s included software, so you can build your own animations. Video of the matrix in motion is after the break.

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Spectrum ZX Laptop

March 19, 2008 by Will O'Brien 13 Comments

[Jim] sent in this interesting laptop modding project. He started with a Spectrum ZX and a Toshiba Libretto 110. The libretto kept its brains, but the lower case and keyboard was replaced with the ZX hardware. Since both machines use matrix style keyboards (but different matrix layouts) he was able to create a passive adapter circuit to match things up.