[vilxes91] sent in this cool little false-theremin (translated). Its a pretty simple circuit, that can fit in really small places. It isn’t a true theremen because it uses the amount of light coming in around the lid for the modulation. To play it, you turn it on and open it up, the more open the lid, the higher the pitch. You can see a video of it in action after the break.
You can get most of the old NES games for the DS, but they just don’t feel the same. Sure your hands still cramp up, but its just not the same cramp we remember. What is the solution? Put an old Nintendo Entertainment System controller on your DS. [Parker] did exactly that. The method he used is fairly strait forward. He opened the DS, wired extensions onto the buttons he wanted to use to a controller. Instead of making it permanent though, he chose to wire it through the GBA slot. This allows him to plug the controller in whenever he wants to use it. This reminds us of the PSP with a SNES controller we covered back in October.
You can see a video of it in action after the break. You’ll notice in the video, he has also modded his buttons to have LEDs behind them.
In the comments, [tri-edge] points out that you can follow his build in the acidmods forum. There seem to be some other variations as well, including an SNES controller.
[Chris] wanted to do some macro photography, but found the price tag off putting. He was looking at roughly $800 for a decent macro lens. Instead, he decided to build his own. He wanted to build a lens that could be removed and used just like his normal lenses. He picked up a standard Canon AF lens for $10 to start with. He has posted detailed steps on how he modded it to work, and you can see the results are quite stunning. Great job [Chris]. If you want to try your hand at macro photography but don’t think you can pull of a job like this, you might want to check out the pringles can macro lens.
If you’re into robotics, you’re probably already familiar with the 2 motor walker. This design, usually used in B.E.A.M. robotics is a pretty easy way to make a 4 legged walking robot. [Edwindertien] has made the design a little bit easier to build with these flatpack walker plans. He used 4mm thick birch, cut by laser to get his walker into shape, but the design would work with almost any material. His walker is Arduino powered, so it could be programmed for all kinds of behavior, especially if you add some sensors. You can see his bot in action after the break.
[Kerry] is building a segway type vehicle for a senior project. Though it doesn’t appear to be done yet, there is some good work finished. As with any balancing bot, it relies heavily on input from a gyroscope, and at least in this case, an accelerometer. That data can be very messy. The sensitivity of the sensor means that people often end up with vibrating or drifting in their projects. [Kerry] has put some work into finding a method of smoothing that results in fast, accurate, but smooth reaction. You can see a video of some comparisons between methods after the break.
[Andrew] sent us this great breakdown of an LCD monitor repair. After his wife’s monitor developed an issue with rippling in the picture, he was forced to decide between trashing it, or fixing it. He decided for the latter, possibly to his wife’s disappointment. The rippling image could easily be attributed to a failed filter in the power supply. Knowing that capacitors are a prime suspect in these cases, he tore in, looking for failures. He found that there were, in fact, 2 bad capacitors on the back light circuit. After replacing them with newer, higher quality ones, the monitor was as good as new.
[Mr. Hasselhoff] is using a disposable cell phone to trigger his fireworks. He has wired into the speaker leads for the speaker phone. When the phone rings, the current sets off a thyristor allowing for a battery pack to be discharged into a rocket fuse. These fuses heat up and ignite, so you can use them to light fireworks fuses pretty easily. This is pretty simple and cheap, considering the price of the cell phone was only $10. His next idea was to have it recognize dial tones and set individual fuses off, but that would require a microcontroller and a much more complex hack. At that point, you might as well just build a fully fledged wireless fireworks launching system and possibly add rocket launching abilities too.
[thanks Adam]
