Fix A Projector On The Cheap

December 22, 2009 by Caleb Kraft 46 Comments

[j] sent in this nice writeup on how to revive a dead projector. he managed to pick one up for $20 that had a broken bulb. While the prices of bulbs have come down considerably, they can still be a couple hundred dollars. Being resourceful, he decide to just use a halogen bulb that he picked up at his local big box shop. In the photos, he’s using a 50w mr16 bulb. The results really aren’t too bad. Especially considering that his cost for the entire project is now roughly $25. He does, however suggest that a 100 watt bulb wouldn’t be a bad investment. His projector seems to need some cleaning and adjustment in the lenses as well, but for $25 it isn’t too shabby. We’ve had this submission for a bit, but it didn’t have any pictures of the projector actually working. During our conversation, we may have possibly suggested a picture we’d like to see. You can find it after the break.

We did cover a very similar one last year, which had the driver integrated into a custom bracket, but the project page seems to be gone. There is also the possibility that the projector you get doesn’t just have a bulb problem. Sometimes it is the polarizer that needs replaced.

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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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BobLight Night Light Networking

December 22, 2009 by Jake W 10 Comments

It turns out that more than just pictures of women and flashing animations can be found on the X10 website. [Jonathan] based his BobLight project around the MS14A X10 module.

The idea for the devices started off as a Christmas gift for his parents in-law. A boblight turns on when motion is detected. It then communicates (through radio) with the other boblights to turn them all on. If motion is not detected by any of the boblights for a length of time, they all turn off. Rather than having the user shut all of them off every morning, a light sensor is used to automate the task.

Each boblight is a common LED utility light combined with the board of an MS14A and added a 310MHz RF receiver. He even hacked the board by replacing the onboard PIC with a higher spec model. We think [Jonathan] did a great job at implementing an innovative concept.

SNES System In The Controller

December 22, 2009 by Mike Szczys 16 Comments

Want to take your SNES emulation to your friend’s house? [Chris] worked out a way to fit the important parts inside of an original Super Nintendo controller. He removed the case from a 4GB thumb drive as well as a USB hub. Using a RetroZone kit he gave the controller a USB interface. By soldering the thumb drive and RetroZone board directly to the hub he’s reduced the package down to just one cable. Everything fits inside the controller case and now when you plug it into the computer you can fire up the ROMs you copied from your original cartridges that are stored on the thumb drive.

Of course this isn’t limited to SNES emulation but the real question is can you boot from the thumb drive?

Rhythmic Combo-lock

December 22, 2009 by Mike Szczys 13 Comments

[MusashiAharon’s] dorm room door was practically begging to be hacked. There was already an electronic strike plate in place as well as junction boxes on the inside and out that were connected by conduit. Jumping on the bandwagon after seeing some other door lock hacks here, he built one that uses a rhythmic combination.

The control panel on the outside is a blank faceplate with two buttons and a status LED. Theses are wired to a jack and connected with a cable traveling through the conduit to a breadboard on the inside of the door. Seeing a large breadboard hanging on an outlet cover is a bit comical but it does the job. From there, a Teensy microcontroller waits for the code and if correct, actuates the strike plate via a relay.

The rhythmic nature of this lock reminds us of the knock-based system. One button signals the start and end of the code, the other is used to input the rhythmic sequence. This does seem a little more discreet and we’d imagine it’s quite hard to eavesdrop on the correct combination.

L2Ork – Virginia Tech Linux Laptop Orchestra

December 21, 2009 by Jakob Griffith 6 Comments

Create Digital Music Wrote a semi guide for Linux music creation and interaction after interviewing the L2Ork group. L2Ork is a Virginia Tech based Orchestra that use only laptops loaded with a custom Linux kernel, Wii remotes, and home built speaker salad bowls to produce some surprisingly amazing music. We’ve seen music creation from Wii Remotes before, but it didn’t sound anything like what L2Ork has created. The best part of the project, there are several videos and guides produced by L2Ork so you don’t have to attend Virginia Tech to produce your own music.

C-clamp Current Monitoring

December 21, 2009 by Mike Szczys 24 Comments

[Hydronic] did some tests to make his own current sensor using a c-clamp wrapped with wire. He tried several different cores including an aluminum carabiner, the C-clamp, and what he calls a u-lock (removable chain link). There is some success here that could be improved with cleaner winding and by adjusting readings based on the length of wire used in the wrapping.

This did make us perk up a bit right off the bat. Reader [Mure], who tipped us off about this, suggested that this could be used to make your own Kill-a-Watt without including it in the circuit. We made the jump to house monitoring. We’d love to have a data tracker for our home circuits to curb wasteful energy use. Perhaps we’ll try to make our own sensors and produce a diy Cent-a-Meter.