Projector Project Bears No Fruit But It Was A Fun Ride

January 9, 2012 by 18 Comments

No matter how good the intentions or how strong your hack-fu may be, sometimes you just can’t cross the finish line with every project. Here’s one that we hate to see go unfinished, but it’s obvious that a ton of work already went into reclaiming these smart white-board projectors and it’s time to cut the losses.

The hardware is a Smartboard Unifi 35″ computer with a projector mounted on a telescoping rod. It was manufactured for use with a touch-sensitive white board which the guys at the Milwaukee Makerspace don’t have. The projector works, but all it will display is a message instructing the user to connect the computer to the white board. Since they’ve got a couple of these projectors, it would be nice to salvage the functionality.

The first attempt was to replace the video signal to the projector. A few test boards were etched to experiment with DVI input. This included several logic sniffing runs to see what the computer is pushing to get the warning message to display. Alas, the group was not able to get the device to respond. But this opens up a great opportunity for you to play Monday morning hacker. Take a look at the data they’ve posted in the link above and let us know how you would’ve done it in the comments.

DIY Fresnel Reflector

January 9, 2012 by 14 Comments

Just like destroying an ant colony with a magnifying glass, there’s nothing like cooking hot dogs and roasting marshmallows with a nice parabolic reflector. Of course covering an old satellite dish with mylar or aluminum tape doesn’t take much skill, however cool it is. [Uwe] came up with a much more technical means of building a Fresnel reflector that will cook your hot dogs in seconds, but only on sunny days.

[Uwe] channeled a little bit of [Apollonius] when he realized that a flat cardboard ring with a section removed could be joined together into a conic section. The resulting section looks just like one concentric ring in a Fresnel reflector. [Uwe] wrote a small program in Visual Basic to calculate the necessary diameter and angle of his conic sections.

A bit of cardboard was cut out and pieced together with some very reflective aluminum tape. The resulting Fresnel reflector concentrates 117 times the normal solar radiation onto a small point. It’s more than enough to burn holes in construction paper, but we’ll be using a microwave for our lunch today.

Got Dead Bugs In Your Stereo?

January 9, 2012 by 44 Comments

It happens to the best of designers, spending untold amounts of time designing a complex device just to find out that you missed a trace, or you couldn’t rout something to something else. As time marches on its becoming a bit less common to pop open a commercially produced device and see a little jumper wire or 2 flying across a pcb, or a resistor straddling an IC.

But when [Ilektron] opened up a Yamaha Dolby Pro Logic receiver to scavenge for parts he saw a very big “oops” and a even wilder fix. The maker took a pair of relays, flipped them “belly up” and hot glued them into place on top of a pair of ICs. Then the mess was “dead bug” wired to the circuit using insulated and uninsulated bus wire, contacts were then reinforced / insulated using more hot glue.

This is one of the most hacky fix we have seen in a commercially produced product, but we would love to hear your amusing horror stories of “WTH did they do?” So join us in the comments after the break.

Programming AVR I2C Interface

January 9, 2012 by 8 Comments

I2C as many of you know, is a simple serial interface for many peripheral devices to micro controllers, but it can quickly become confusing to people who may not be accustom to it. Because of that, I2C tutorials are always welcome, and this new tutorial by [Embedds] does an excellent job of how to use I2C with an AVR with a 24C16 2Kbyte EEPROM.

The first half of the tutorial provides a clear explanation of how I2C works, including its signal structure, addressing, and data packets. It then moves on to AVR territory showing how to setup the I2C in an AtMega micro controller. The author uses a pretty standard to most of us Arduino, with software written in AVR C and a nifty little GUI programming application which eases the hassle of dealing with AVRDude directly.

Plenty of code samples follow from twiddling registers to a full blown application reading and writing bits from the EEPROM to a serial terminal on a PC.

[Alex] Shows Us What Happens When Dance Dance Revolution Meets Simon

January 8, 2012 by 5 Comments

ddr-simon

[Alex] was digging through his closet and came upon an old PS2 game pad for Dance Dance Revolution. He hated the idea of throwing it out just slightly more than the idea of playing DDR again, so he decided to find a way to reuse it.

He was a big fan of the game Simon (aka Genius) as a kid and thought that the DDR pad would make a novel interface for the classic game. Using the PS2XLib by [Bill Porter], which allows an Arduino to easily communicate with a PS2 controller, [Alex] put his Simon replica together in no time flat.

He painted an empty ice cream container with the classic Simon colors, installing a small LED under each quadrant, then wrote the game’s code.

As you can see in the video below, his version of the game works nicely, and forces you to actually get up and move a bit, which we like.

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DIY Shade Finder Tool Takes The Tedium Out Of Solar Surveys

January 8, 2012 by 20 Comments

diy-shadefinder-tool

[Steven Dufresne] does a lot of tinkering with solar-powered applications, a hobby which can be very time consuming if done right. One process he carries out whenever building a solar installation is creating a sun chart to determine how much (or little) sun the target area will get.

The process requires [Steven] to take elevation and Azimuth measurements of many different points, which often consumes about half an hour of his time. While taking measurements recently, he started thinking about how he could improve the process, and came up with a stellar solution that reduces the process down to a one-minute task.

In short, his shade finder tool uses a pulley, a pair of rollerblade wheels, and a pencil to accomplish a full shade survey in under a minute. The science behind the tool is best explained by [Steven], so be sure to check out his site for plenty of details and diagrams.

We have to say that we’re extremely impressed by his shade finder – hopefully his work can help others maximize the efficiency of their solar solutions.

Stick around after the jump to see a short video of the shade finder in action.

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Rainbow Board Of Many Ping-pong Balls

January 8, 2012 by 13 Comments

[George] just finished his first project: an 8×8 matrix “Board of Many Ping-Pong Balls” with 64 RGB LEDs. He started this project when he was 14 years old and finished the build over this last Christmas break. We won’t make any presumptions about [George]’s age, but we couldn’t think of a better project to start out on.

For the build, [George] used a Colorduino LED driver shield for his Arduino. This made the wiring simple, but the finished product is where this project really shines. For the base, [George] got a board laser cut at his school and used ping-pong balls to diffuse the LEDs. We’ve seen this many times but with this build there’s a neat way to drill a hole in a ping-pong ball; simply put the drill into reverse. The friction is enough to open the ball up, and the chips of plastic come outside instead of remaining in.

We’re really impressed with [George] and his winter break project. He’s lucky enough to have access to a laser cutter at school, and from a look at his monitor, he’s reading the right websites. You can check out his demo rainbow pattern after the break.

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