Numato.cc is having their 2014 Mega Give Away. You could become the proud owner of one of the many electronic boards they offer. They extended the deadline to this Saturday, get in while you still can!
I have tinkered with small PVC rocket motors using sugar fuels in years past thanks to information posted by Richard Nakka, Dan Pollino, and Jacob's Rocketry. The frustrating part of the build, particularly for smaller diameters, was the nozzle. After building a 3D printer, it was time to print my own nozzle molds.
I have posted an alpha release of the BasicSDAudio library on GitHub! Check it out here. It is capable of 78125Hz stereo PWM audio outputs read from an uncompressed RAW file on an SD card. Psuedo 16bit playback should also be possible.
Also, here is a quick demo of the library running with my BabyBOOMER amplifier/buffer/filter prototype at 78125Hz, 8bit, mono output:
Testers and collaborators are welcome. Future improvements to the library include: