wb8nbs created an Si5351 powered signal generator.

This compact signal generator is packed into a tin that’s just slightly bigger than the ones those curiously strong mints come it.  It uses a breakout board with Si5351 and a TCXO from Etherkit.com.  A TCXO (Temperature Compensated Crystal Oscillator) allows for very accurate frequency.  The unit brings out all three signal outputs, individually programmable for frequency (500 Khz to 160 Mhz), sweep width and limited level control. There is a Teensy LC for control using Si5351 libraries from Jason Milldrum NT7S. The battery and charger are out of a cheap cell phone booster.

You can read more about the project on wb8nbs’s blog.  A zip archive of the code for the project as well as a schematic can be found here.

Sebastian Tomczak made a simple, but cool drum machine using a Teensy-LC.

Code for the project is available here.

Michael Diesing (forum user Joegi) built a solar powered chairoplane model.

Inspired by a chairoplane model  he already owned that only worked on bright summer days, Michael made this improved version that works even in winter.  He did this by creating a circuit where two solar cells charge 2 5F, 3V super capacitors.

Freeside, a hackersapce in Atlanta, built a 10-foot tall infinity mirror.

They did a great job documenting the build in this video.

This impressive build features a 7 x 4 ft infinity mirror mounted in a 10 ft tall archway.  They used WS2812 addressable LEDs driven by a Teensy to create the infinity effect.

Barkus Labs made a cool LED graduation hat.

Using a 32×32 neopixel display, a Teensy 3.2, and a bluetooth module, he was able to make the display programable via a smart phone.  He has an additional video showing the code for the project as well as a link to a Google drive with the code.

His build inspired Sirrom0206 to build an LED graduation cap for a friend’s son.  He posted a video about the build here.