FPGA keyboard synthesizer

This synthesizer relies solely on an FPGA for key detection and sound synthesis. [Chris] and [Joe] built it for their final project at Cornell. The hardware implementation includes velocity sensing for the keys. While at rest, each key contacts a strip of copper foil. A matching strip of foil contacts the key when it is depressed. The velocity data is extrapolated by detecting when a key leaves the rest state and arrives at the depressed state. Sound synthesis is handled in hardware using the Karplus-Strong string synthesis method. If you want to hear what it sounds like, they’ve posted a video (MP4) that shows off the creation. It sounds like an electric piano to us, so mission accomplished.

Read more...

Hey man, you seen my turntable around here?

It’s all fine and dandy to have a turntable that sounds great, but [Mike] wanted one that looks great too. He build the transparent record player above and loved it for a little while. When his interest in it waned he built another, then several more. They all have some element of transparency to them, and each is a work of art. Makes us wonder how often he needs to dust his house to keep them looking so good.

Is turntable technology too advanced for your tastes? You can stick with your Edison cylinder, we won’t make fun.

[Thanks John]

Read more...

Making a rail gun

[Rp181] is at it again with version 2 of his rail gun project. The original did have some power with 18 400V 3900uf capacitors, but he’s ramped it up to now using 40! Reaching more than double the amount of joules of energy, 12kJ vs. the 5.6kJ! Some other changes include a new injector solenoid setup and revision 3 of his breakwire chronograph. Sadly, he doesn’t mention if this is as green as his first rail gun. Check out a video of just the injector firing and an animation explaining some new updates after the jump.

Read the rest of this entry »

Read more...

Trailer side indicator lights

[Imsolidstate] is working to add side turn signals to a trailer. These orange clearance lights are illuminated when the vehicle’s headlights are on to increase a long trailer’s visibility. They also blink along with the turn signals on the back of the trailer. A standard 6-pin lighting harness doesn’t support this functionality so the trick is to add them without altering the towing vehicle in any way. He’s using an ATtiny24 microprocessor to interpret the logic from the vehicle and then translate the turn signal and tail light data into a signal for the additional side indicators.

Read more...

Meat smoker from 55gal drums

[Joel] wanted to use his newly acquired welding skills to make something useful. With tasty flesh in mind he put together this meat smoker. What resulted is incredible, but the fact that he then gave it away as a gift is just amazing.

A curved joint between two pipes is known as a ‘fish mouth’. They can be a hassle, as with the pirate wheel project, but [Joel] used his noggin to make things easier. He first modeled two 55 gallon drums in CAD. The intersecting curve was then generated by the software, printed out on paper, and stenciled on the drum to be cut out with a jigsaw.

[Joel's] writeup is greatly detailed and shares many pictures. He makes every part of this smoker, including the wood handles and the stainless steel grates. The guy really knows how to build stuff, but we should have known that after seeing the Crushtoberfest.

Read more...