Working With VFDs

December 25, 2008 by Eliot 12 Comments

vfd

We love old display technology, like Nixie tubes, but they’re often difficult to work with because they require higher voltages than digital logic. Vacuum florescent displays (VFD) fall into this category. While not necessarily “old”, they are becoming far less common than LCDs. The main benefit of a VFD is that it actually produces light directly; it doesn’t require a backlight. You’ll find these displays on various players and appliances: CD, DVD, VCR, microwaves, stoves, car headunits, and others.

[Sprite_tm] had written off some VFDs, but recently revisited them with renewed interest. He started by testing what sort of voltage would be required to drive the display. It took 3V for the filament plus 15V to drive the grids. There are VFD controller chips available, but he wanted to get this working with what he had on hand. He had experience with older 40xx series logic, which can be powered by much higher voltages than 5V 74xx. His final schematic has three 4094 serial to parallel chips with an ATtiny2313 controller. A 5V power supply is dropped to 3V with diodes to drive the filament while a boost converter brings it up to 15V for the 4094s that switch the segments. While the code is specific to this display, it would be a great place to start your own project.

Giant LED Lamp

December 24, 2008 by Caleb Kraft 15 Comments

led

[guyfrom7up] must really really love LEDs. When he needed some lighting, which would obviously be LED powered, he chose to actually build a giant LED. Well, he didn’t actually build a giant functional LED, but rather an LED shaped diffuser for some high powered LEDs. He takes us through the process of first creating a wooden model, using that to create a mold, then forming the final diffuser. The final product is very well done, and instantly identifiable by any geek.

[thanks Brian]

Digital Clock Building

December 22, 2008 by Eliot 10 Comments

[punkky] has been documenting his adventures building digital clocks. They each use six 7-segment LED displays, but he’s been gradually changing how they are built. The first version used a CMOS BCD-to-7-sement latch on each display, which is tied to a PIC16F627a. For the next run, he added multiplexing, so he could drive all the segments using just thirteen pins. He’s posted a final schematic with code and details of how the clock timing actually works.

Cast Concrete RGB Lamp

December 22, 2008 by Caleb Kraft 1 Comment

lamp

[matthew venn] shows us how to create this cool RGB LED lamp. There’s nothing groundbreaking here, but some good information on casting the base out of concrete. The body of the lap is formed by two thin rods folded in half, stuck in holes in the base, with a lycra sleeve slid over them. The final effect is quite nice and can be controlled by 3 knobs recessed in the front of the base. Information on the actual circuit used is very limited, as there are so many tutorials out there for that, but he does show how he mounted it all, and plans on releasing the source code soon.

A ShiftBrite Christmas

December 13, 2008 by Eliot 11 Comments

[youtube=http://www.youtube.com/watch?v=8PVC5jABuB8]

[Garrett] took 30 of his ShiftBrite modules and mounted them to his front fence for Christmas. The ShiftBrite is a serially addressable high output RGB LED. The individual modules are quite adept at applications like this where you’re stringing multiple lights together. They have identical buses on either side, specifically for daisychaining. The installation above looks great.

Edge-lit Holiday Cards

December 10, 2008 by Eliot 8 Comments

edgelit

Got 30 minutes for a holiday project and don’t want to get wrangled into some sort of decoupage disaster? Evil Mad Scientist Laboratories can show you just how easy it is to do edge lighting effects. Pictured above are three holiday cards constructed using scored plastic. You can use many different types of clear plastic for this, not just acrylic. The lighting is just an LED on a coincell. Black tape is used to prevent light leaking from the edges. The red and green version above is two stacked layers. This looks like something fun to scale up for a larger project or just to kill some time.

LED Projector

December 6, 2008 by Caleb Kraft 6 Comments

led_projector

[PuffMag1cDrag0n] shows us how to make a fairly simple projected LED display. The projector is made from a 13×7 LED matrix and a couple fresnel lenses. The layout and construction is similar to the Lumenlab projector setup, only replacing all the lighting and LCD with an LED array. It communicates via serial port and is powered by a pic micro 16f648. We would love to see an RGB version of this. The directions are a bit rushed, but you should be able to get the gist. Just remember that you need some pretty powerful LEDs to throw a big image.