Pedal-powered 32-core ARM Linux server

Sure, it’s probably a gimmick to [Jon Masters], but we absolutely love the pedal-powered server he built using a group of ARM chips. [Jon] is an engineer at Red Hat and put together  the project in order to show off the potential of the low-power ARM offerings.

The platform is a quad-core Calxeda EnergyCore ARM SoC. Each chip draws only 5 Watts at full load, with eight chips weighing in at just 40 Watts. The circuit to power the server started as a solar charger, which was easy to convert just by transitioning from panels to a generator that works just like a bicycle trainer (the rear wheel presses against a spin wheel which drives the generator shaft).

So, the bicycle generator powers the solar charger, which is connected to an inverter that feeds a UPS. After reading the article and watching the video after the break we’re a bit confused on the actual setup. We would think that the inverter would feed the charger but that doesn’t seem to be the case here. If you can provide some clarity on how the system is connected please feel free to do so in the comments.

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Bicycle quadcopter flies for dozens of seconds

If you decide to fly into town on this bicycle-powered quadcopter your arms and legs really will be tired. That’s because this athlete had to give it his all to power the rotors through the foot pedals and the hand cranks. You can see just one of the rotors on the right side of the background. Yeah, this thing is big!

You’re looking at the Gamera II, a craft developed by students at the University of Maryland. About a year ago they were showing off the first version of the aircraft. With the passing of the year comes the breaking of world records as a different rider manages to keep it up for 50 seconds in the video after the break. Although the structure is huge (over 100 feet across) the building materials and techniques let it weigh in at only 71 pounds.

It still looks like way to much physical work for us. We’re sticking to the pedal-powered hydrofoil as our dream transport.

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Foot-controlled mouse keeps your hands on the keyboard

A bit of mechanical ingenuity makes building this foot-controlled mouse into a fun project. It consists of a platform which hosts one pedal for each foot. The right foot controls the movement of the cursor, and the left is responsible for the buttons.

The guts of a wireless mouse do most of the electrical work for this hack. You can see that the optical sensor is mounted on the front of the right foot pedal. A ball bearing combined with a hinge provides motion on two axes. This moves the sensor past a piece of curved foam made by covering a ball with plastic wrap then spraying foam insulation around it. The pedal on the left has four buttons actuated by moving the toes down, up, left, or right. There’s a centering mechanism for this pedal which uses a rubber band

One thing we wonder about here is whether there is a need to lift and re-center the mouse/cursor? There is also no scroll wheel. But those issues are just waiting for someone to pick up the project and make their own improvements.

LEGO wah-wah pedal

Here’s a guitar wah-wah pedal that [Christian Munk] built. Inside you’ll find a circuit board that he etched and populated based on this design but he chose to build the housing out of LEGO. The video after the break gives you an idea of what it sounds like, but for those who’ve stepped on a LEGO piece with bare feet, his pedal pounding might make you cringe!

To manipulate the sound the pedal rocks forward and backward on a center pivot shown above as a grey “nut” sticking out the side of the frame. Inside there’s a system of LEGO gears that turn a trimpot to alter the sound. This might go along nicely with that guitar amp you hacked together.

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Building a germanium fuzz face guitar pedal

Rock in the new year with a guitar pedal you built yourself. [Doug Kovach] took the time to share his project with us in the video after the break. He starts with a bit of history of the artists that have used fuzz pedals similar to this one. It seems great guitarists have been hacking since way back. [Doug’s] rendition uses the warm sounds of germanium transistors in a design that produces professional results. But if you need something a little bit less serious try the stomp-box.

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Guitar echo pedal built with mbed

[Vsergeev] built an echo pedal for a guitar or with other audio manipulation applications. He used an mbed microcontroller for the project. You may remember Hackaday writer [Phil] labeling the mbed an ‘Arduino on steroids’, and it certainly handles this audio processing quite well. We’ve included a clip of the echo effect after the break. During the design process, [Vsergeev] used LTspice to simulate the analog circuitry and make things right before committing to the physical circuits.

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Homemade Tube Screamer clone


[jonboytang] documented his construction of a clone of the famous Tube Screamer overdrive pedal from a set of plans found at tonepad. The tonepad site says you can use the plans to build either a TS-9 or a TS-808, both of which have been classic staples in every guitar player’s setup since the 70s. Although the old parts are no longer available, these new variants still have a really nice sound.

This project is really just a look into [jonboytang]’s etching and enclosure building process, but it may be useful for someone. The build and the circuit look really simple so this would be a great project for guitar players looking to learn how to etch their own PCBs. If you need more information on etching, we would suggest starting out by reading our How-To on etching single sided PCBs. If you are lazy and would rather spend a little money, check out tonepad’s online store. They have a board for this project and many others.