Epson Projector LED Mod

March 28, 2013 by 46 Comments

Projector bulbs can be incredibly expensive to replace. Sometimes it’s more cost efficient to just buy a whole new projector instead of a new bulb. [Shawn] recently found a nice deal on an ‘as is’ Epson EMP-S4 on eBay and decided to take a chance. He assumed it probably worked with the exception of the missing lamp the seller mentioned. His suspicions were correct, and one custom LED mod later, his projector was up and rolling.

Without a stock lamp installed, the projector would give an error message and shut itself off. So, the first step was to wire up a little bypass. Once that was taken care of, [Shawn] installed a 30W 2000 lumen LED and custom fit an old Pentium CPU heatsink to keep the LEDs temperature down. He also wired up the heatsink fan in parallel with the stock exhaust fan for good measure.  Optical lenses help focus the light, and some custom wiring makes the LED turn on and off just like the stock lamp would.

In the end, his first experiment was a success, but [Shawn] wants to try an 8000 lumen 100W LED to make it about as bright as the stock lamp was. Check out a little video walkthrough after the break.

[Thanks Shawn]

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Centerpieces For A Geeky Wedding

March 28, 2013 by 17 Comments

[Bill Porter] is a married man now, and evidently his new wife, [Mara], is awesome. They put together one of the geekiest weddings that included custom side-lit LED centerpieces.

Instead of laser engraving the dozens of plastic panels for each centerpiece, [Bill] tricked [Mara]’s Silhouette Cameo home vinyl cutter – the same one they made their invitations with – into engraving acrylic panels. They’re made out of very thin plastic, but the fact that the couple were able to snap apart the engraved plasic after putting sheets though the machine is very impressive for something that’s generally used for scrapbooking.

As for the base of each centerpiece, [Bill] whipped up a few enclosures on his 3D printer and built a few battery packs out of 18650 lithium ion cells. The nine LEDs in each base were leftovers from a previous project involving LED strips, perfectly suited to run for a few hours in a reception hall.

It’s a great build for a wonderful occasion, and we’re really impressed with the plastic cutting ability of the Sihouette Cameo. Very nice work there.

Handwriting Robot Arm Is A Little Stiff-wristed

March 27, 2013 by 13 Comments

handwriting-robot

Check out this robot arm capable of handwriting which is orders of magnitude clearer than our own. It was built by [Patrick Barnes] as contract work for a campaign to raise funding for research into Duchenne Muscular Dystrophy.

Don’t miss the video after the break which starts off with the satisfying whine of some serious stepper motors. Judging scale from this image is a bit tough, but [Patrick] tells us that the entire assembly stands almost fourteen inches tall and the arm has a reach of around twenty inches. The demonstration shows off it’s abilities by drawing a Hilbert Curve. From watching the action you’ll realize that, though this arm and hand look fantastic, this is really a SCARA plotter. The wrist and fingers are for looks only, providing a place where the felt-tipped pen can be mounted (held flush to the paper with a rubber band). Whether that’s a disappointment or not, the precision and look of the machine bring it very high marks. It could take a bit of a lesson in penmanship from another we’ve seen though.

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Hi-Hat MIDI Controller

March 27, 2013 by 10 Comments

midi-hi-hat-controller

Drumming hackers take note, if you’ve got an extra bass drum pedal it’s cheap and simple to use it as a MIDI controller. This rig was thrown together to supplement a DIG DRUM electric drum set. That piece of equipment has a pedal add-on that didn’t come with it. Turns out all it does is feed a resistance value to the set.

To get this up and running a frame was built from a metal base and acrylic side piece. The acrylic hosts a trimmable potentiometer which connects to an 1/4″ stereo jack right beside it. This facilitates connecting the pedal to the drum set using an audio patch cable. Interface with the pedal is accomplished with a few bits from the hardware store. The axle of the pedal sticks out one side, and is clamped between two washers. The other side of the washer grip the timpot causing it to move when the pedal does.

This hardware is a snap to use with your own MIDI device. We’d suggest giving the HIDUINO package a try.

Color NTSC Video Directly From An AVR Chip

March 27, 2013 by 27 Comments

color-ntsc-from-avr-chip

We’ve seen composite video out from AVR chips many times before. But we can’t remember coming across one that managed to produce a color signal. This project does just that, producing a color video signal from an ATmega168 without using external integrated circuits.

[CNLohr] is seen here showing off his accomplishment. You’ll remember him from the glass-slide PCB server project he’s been working on recently. This time around it’s a small piece of gaming hardware which he’s working on. But using four pins from the microcontroller, connected via resistors in parallel, he is able to generate a color NTSC signal without using a chip like the AD723.

After the break you can see the two minute demo in which he shows the game running for just an moment, then gives a general overview of how the signals are being built. There isn’t a ton of explanation, but he did post his code as well as a resource for you to teach yourself more about the NTSC standard. Maybe you can make a color version of that AVR tetris game?

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Business Card Draws [ch00f]’s Logo

March 27, 2013 by 23 Comments

[ch00f] is at it again, expanding the horizons of the art of PCB business cards. This one draws his logo on any computer over a USB port.

The physical design of the card is heavily inspired by [Frank Zhao]’s card; both use an ATtiny85 and the V-USB package to handle the USB protocol and communications. Instead of typing words into a text editor like [Frank]’s, [ch00f]’s card draws the ch00ftech logo in MS Paint or other image editor.

There was a problem with simply emulating the mouse to draw a logo on the screen, though; because different computers have different mouse settings for acceleration, the ch00ftech logo was nearly always distorted. [ch00f] fixed that by emulating an absolute input device, basically turning his business card into a single-function pen tablet.

The logo was traced by hand and put into a few arrays in the firmware. Surprisingly, the logo didn’t take up much space – only 4k of the tiny85’s flash is used. There’s a lot more space for a more complicated drawing, but for now the simple ch00ftech logo (video after the break) will do.

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Making A 12V Bulb Work In A 6V Socket

March 27, 2013 by 28 Comments

12v-led-in-6v-socket

This is something of a square peg in a round hole type of problem. [Kiel Lydestad] has been riding a vintage Moped around. You know, a motorcycle that can be pedaled like a bike. He of course wants to keep the thing looking stock, but also needs it to be fully functional. Enter this light bulb replacement project. His brake light needed a new bulb, and he managed to make this 12V LED bulb work in the 6V socket.

An LED is a really great choice for this application since the Motobécane Moped uses a magneto generator to power the lights. It won’t pull much current, but it did need modification to run from half as much voltage. [Kiel] mentions that it may have been possible to crack open the LED tower and adjust the current limiting circuit inside, but he felt it was easier to just add this voltage doubling circuit. He assembled the components in a way that still allows them to fit in the metal base of the bulb.