Porkshanks commissioned me to design an LED color organ driver for a functional art-piece modification of an electric violin, for Maker Faire. She herself had been commissioned to convert an electric violin to a tubepunk aesthetic, and was looking for a lighting effect more sophisticated than a plain glow. I built one that drives brightness based on loudness and huge based on pitch.

Direct link in case flickr is being obnoxious

I'm working on a commission that calls for a 3-color LED to respond to audio input. With appropriate parameters, it produces a fairly convincing flame effect. Here it is inside an egg Naj made for entirely unrelated purposes.

This week was a research phase. I'm putting together parts for a spectrometer.

Ingredients:

• The Optics of Spectroscopy - A TUTORIAL By J.M. Lerner and A. Thevenon
• Inexpensive 102-element photodiode array with built-in ADC
• Inexpensive holographic diffraction grating film

I just need some mirrors and I'm mostly set. I'm going with what is mostly a Czerny-Turner monochromator design, with two differences. First, the grating is a transmission grating, not a reflection grating, so the bottom half "flips around". Second, I'm using an imaging sensor rather than a single exit slit, so it's not actually a monochromator.

And here's a bonus photo I took of some lightbulbs through a diffraction grating. Incandescent on top, CFL on the bottom: