[Ania] wrote in to let us know her team had finished the Multixylophoniomnibus and that they have posted an extensive writeup about it. We covered this augmented xylophone when it was still in development at the beginning of this month. Originally they wanted to use mallets wrapped in tinfoil as switches that close when they contact the metal keys, something akin to matchbox cars as a switch. This plan was thwarted when they realized the paint surface insulated the metal keys. At this point they switched to piezo sensors which turned into an odyssey of trial and error to achieve a reliable input for the Arduino to monitor. In the end they got it working with around forty lines of code, interfacing six boxes containing a different type of noisemaker.

See the finished instrument played in the video after the break. Alas, the addition of the piezo sensors do impede the resonance of the xylophone keys, but we still like it! There’s something reminiscent of the beginning of Pink Floyd’s Money when this is played.

[Gio] enjoys using vacuum tubes in his projects. He designs the circuits using a CAD program but was finding that there is no substitute for actually building a prototype before heading to a final design. To make this process easier, he built his own tube prototyping station.

At the top of the board he’s got three different sizes of tube sockets with the pins from each wired as common. The nine pins from the sockets break out to a terminal strip where they can be interfaced with a solderless breadboard. For added versatility he’s included terminals to tap into some RCA jacks, as well as a 100 kOhm variable resistor. We’d bet this is not something that you can find ready-made, but it sure does look a whole lot better than a workbench full of components alligator-clipped together.

How often do you change the batteries in your television remote control?  Yeah, basically never. But that’s a tribute to how efficient the device is and not a reason to overlook this development. NEC is showing off a remote control that uses no batteries. Power is generated using the piezo effect that occurs when a button is pushed. That is to say, when a crystal is compressed it emits a tiny bit of electricity which is harnessed and used to power this device. This is the same principle that is used in the electricity producing sidewalks tested in Japan.

It’s pretty phenomenal that they can run the device using this method. Right now there’s only a handful of buttons but we’re sure there’ll be advances in the technology. There’s a ton of use for this if it can be miniaturized. It is using radio frequency instead of infrared, making it a useful development in wireless doorbells, garage door openers, key-less entry fobs for your car, and many more applications.

[Thanks das_coach]

As you can see above, there is no wiimote in that accessory steering wheel. There is, instead, a home-made accelerometer controller that connects to the pc via USB. Based around a PIC 18F2550 and a 2 axis accelerometer, this device is detected by windows as a standard controller. The schematic and source code are available on his website. He says it can also be used as a “motion mouse”. You can see a video of that after the break.

When we first saw the video, we thought it might be the same person as the accelerometer controlled maze project, due to the wiimote steering wheel casing.

[via make]

[Maurice] let us know that his latest photography tool for hackers, the Camera Axe 3.0, is now available. The original allowed you to trigger a high-speed flash and camera from a multitude of sensors, including light and sound. The new one does all that, but also: allows multiple cameras or multiple flashes, clean up of software to make it more user adaptable, and the best (arguably the most important) part – cheaper components! All that and more under the Creative Commons that we do love so much. Keep up the amazingly detailed and just pure awesome work [Maurice].

This neat accelerometer controlled marble maze adds a level of fun to retrieving a gum ball. You have to first navigate the maze using a controller that has a dual axis accelerometer in it to control the angle of the platform. Though that does look like a wii accessory, there is no wiimote in there.  Only after you have completed it will the gum ball machine dispense the candy. [Dan] constructed everything himself, which might explain the lack of “pits” for the marble to fall into in the maze.

More details on the build and source code are available on his page.

[via hacked gadgets]

[Shingo] shared his implementation of a stationary bike as a virtual reality interface. This is similar to the Google Street View setup we covered a week ago but goes a few steps further. They patched into the bike computer to pick up rotation of the bicycle wheel and added an accelerometer for directional control. This setup can navigate through Street View but the video after the break also details an interface with Google Earth and even the ability to navigate through Second Life, following your avatar as it bikes along with you. The use of a wearable display is far superior to something like the SurfShelf and really gives you a goal other than just some cold-weather exercise. So take this idea, patch it into a wearable computer and you’ve got the exercise setup worthy of the future world we’ve been promised.

[Jack] wrote in to let us know about a project that creates a virtual microprocessor core based on the ATmega103 by using a Field-Programmable Gate Array. Great, we thought. Here’s another rather esoteric project like the NES on a FPGA, but what’s the motivation behind it? We asked [Jack] and he provided several scenarios where this is quite useful.

Implementing the AVR core allows code already written for the chips to be easily ported to an FPGA without a code rewrite. This way, if your needs outpaced the capabilities of the microcontroller long after the project has started, you can keep the code and move forward from that point with the added capabilities of the gate array. Having the core already implemented, you then only need to work with HDL for the parts of the project the AVR was unable to handle. He also makes the point that having an open source AVR core implementation provides a great tool for people already familiar with AVR to study when learning VHDL.

With products like the Butterfly that this project is based around, or the Maple we’ve seen in the past, programmable logic for the recreational hacker is starting to get a little easier.

[Chris] wanted a guitar with a keyboard but didn’t want a keytar. Like any good hacker he took a cheap guitar and a small keyboard and introduced them to each other. He moved the control knobs to make room for the keyboard and added the control circuitry from the keyboard to the top of the guitar’s body. A 9v battery is used to power the keys and something called “Chris Collins’ transformer trick” is used to amplify its sound. If you know details on this transformer, leave a comment and we’ll update the post. Take a look at the video after the break to see [Chris] perform the Final Countdown on keys and guitar.

The guitar is a Chinese made Telecaster clone and we think he’s the first one to find a realistic use for keyboards that don’t use full-sized keys. [Chris] apologizes for the lack of build photos but we give him a pass; he lost his phone while crowd-surfing and that’s as good an excuse as any for losing some pictures. We can’t wait to see another performance with this gnarly axe once he’s had enough practice to pull everything together!