Blog Posts

Digital Setting Circles for Dobsonian Telescope

Aaron Turner built his own digital setting circles (DSCs) to add to his 12″ Dobsonian telescope after finding the commercial options were pricey and lacking in a good user interface.

DCSs show you where to point your telescope to locate your astronomical target.  They are particularly useful in areas of high light pollution.  You can read more about them here.

Powered by a Teensy 3.1, Aaron’s digital setting circles allow connecting
your computer, iPad or Android device to your telescope via WiFi to
more easily find any object in the night sky.

More information on the project can be found on the Teensy-DSC Wiki.  The code for the project can be at TeensyDSC on GitHub.

DIY USB Security Token

Drew Fustini tweeted about a presentation he saw at LinuxCon 2014

A Teensy 3.1 was used for a DIY security token.  The functions inlude Trusted Platform Module (TPM) for Integrity Measurement Architecture (IMA) attestation, signing files, and ssh remote login.  Some of the features include private keys generated on the token and a physical presence required to reprogram.

The token was simply constructed using the housing from a USB thumb drive and some epoxy to keep it all together.


MIDI Joystick

Forum user whannah built a nifty MIDI joystick so that he could control a synthesizer from his organ.

This joystick solved a couple of problems for whannah.  He wanted to control a synthesizer from his organ, but  wanted a physical control for pitch bend and modulation, which the organ doesn’t have. Also, he couldn’t plug the organ into the synthesizer because the MIDI control change (CC) messages are sent to the synth when he didn’t want them to be. He couldn’t disable the sending or receiving of MIDI on either instrument. Normally he would need to bring a second keyboard to control the synth, which is a pain. So he built this little joystick box to give him a physical control and also filter the MIDI messages.

You wouldn’t know by looking at it, but whannah said that the hardest part about the project was drilling the holes in the right place.


Sound-reactive Kinect tracking LED wall

Sammy Kamkar created an amazing sound reactive LED wall

This 4×4 wall has 1,728 addressable LEDs and tracks anyone in front of it via Kinect. Samy does smart background subtraction by creating a “depth window” in 3d space as the Kinect can provide me full depth data. The software is a combination of code he’s developed in OpenFrameworks, Syphon and Quartz Composer for sound reactivity. The panels are driven by a $19 micro-Teensy board using Direct Memory Access.

Symphony Hack Lab Light Cubes

Andrew Pelling and the pHacktory recently made beautiful light cubes as part of Hack the Symphony with the National Arts Centre Orchastra.

This video posted on Twitter shows the testing of the cubes prior to the performance.

Andrew used a MSGEQ7chip to turn incoming audio and break it down into seven frequency bands.  The data is sent to a Teensy 3.6 to control and assign colors to the LEDs lighting up the cubes.  The result was an art installation that translated orchestra sounds into colors – blues purples for bass frequencies with higher frequencies in red.  Each cube will also get brighter or dimmer depending on the volume level of the music.

This article gives a great overview of the project as well as instructions for building your own.  Addtionally, all the code is available on GitHub.

You can read more about the project and Andrew over on artsfile.



Twitter Taxi

Forum User digital11 outfitted a 1922 Checker Cab with Ws2811 LEDs that react to music that can be requested over Twitter.

Check out this video showing the LEDs in dancing action.

Some of the technical details ditigall11 provided on this project include:

5 Teensy’s running OctoWS2811 (Probably went a little overboard here, as I wanted the Teensy’s as close to the strips as possible, so I’m not using OctoWS2811 to its fullest, but I’m sure PJRC doesn’t mind :P)

Ableton Live/Max4Live/Jitter handling the music playing & video generation. Wrote a serial external for Max that basically generates a bytestream formatted for OctoWS2811 from a jit.matrix, so any video can be piped in realtime to the Teensy’s, with whatever fx/beat syncing is desired (Major props to nlecaude for the foundational work on this.)

Custom OSX app to monitor Twitter, queue up the requested songs, and update a tv display showing the song queue, available songs, and currently playing song.