LED Matrix With A Gross Of Pixels

July 21, 2010 by Mike Szczys 19 Comments

This LED matrix is arranged in a 24×6 pattern for message scrolling. There’s no etched boards here, making us wonder where [Syst3mX] found protoboard this long. He’s using an Arduino to drive the demonstration (clip after the break) but you can use any microcontroller with this setup. That’s because he’s using three shift registers for column data and a decade counter for row scanning, requiring just five control pins.

While you’re going to the trouble of ordering components, maybe you should try your hand at building a touch sensitive LED matrix too.

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Wire-wrapping An LED Matrix

June 3, 2010 by Mike Szczys 20 Comments

Regular reader [Osgeld] built a 1024 LED display matrix. This is a proof-of-concept design and he admittedly has overloaded the components. Most notably, the 595 shift registers (featured over the weekend) are sourcing too much current if all eight pins are active. That’s easy enough to fix in the next design by moving up to cascading LED drivers. Instead of soldering every connection in the display, [Osgeld] soldered the components in place and then used wire wrapping to make the point-to-point connections. This must have saved him a ton of time and frustration. We can’t wait to see what comes out of this first prototype.

What Kind Of LED Matrix Does Your Vodka Come With?

April 14, 2010 by Mike Szczys 40 Comments

Medea Vodka comes with a bottle that includes a blue scrolling LED Marquee. OK, great? It’s an interesting marketing ploy but kind of a waste don’t you think? Friends, it’s up to us to repurpose this hardware. It can’t be that difficult to hack into the programmable display and make it do your bidding. Our friend Google tells us that you can get your hands on this 750 milliliter bottle for about $40. That’s around $25 more than a passable grade of Vodka sells for, a mere pittance for the challenge of cracking open the hardware for fun and profit. Don’t forget to document your work and tip us off once you’ve accomplished something. See Medea’s programming instructional video after the break. Oh yeah, remember to hack first and drink later… cheap soldering irons get hot!

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Modular Systems Using SPI

December 22, 2009 by Mike Szczys 5 Comments

[Humberto] is at it again with a NerdKits video detailing the use of an SPI bus to communicate between microcontrollers. He started with a previous LED marquee project which was limited to a 5×24 LED Matrix and developed a modular solution to increase the size limitation.

The writeup and video embedded after the break do a great job of detailing the important differences between a stand-alone and a modular system. The good news is that the ATmega168 chips being used have a built-in interrupt based SPI protocol. Once wired correctly, a master control chip addresses each module separately, adding data to their buffer until a full frame has been transferred, then moves onto the next module.

Some of the caveats to this system such as digital transmission over long distances are discussed. We do wonder about power limitations if all LED’s in the marquee are illuminated at once. But that concern aside, if you’re thinking of playing around with an LED display don’t forget that there’s usually a huge price break for orders of 500 or 1000 LEDs!

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