Rick Van Melis created Trees of Life, a beautiful and interactive art installation that allows visitors to connect with the 2 trees and bring them to life.

The art installation features over 9,000 LEDs controlled by 8 Teensy boards using the Fast LED library. Each tree is a separate system. It has 6 hands and 12 ‘arteries'(LED-Strips) 2 out of each hand. These start at 1m50 and go 5 – 7,5m high.  Basically when untouched the tree and its arteries are in a restful idle animation. Users however were able to wake up the tree by placing their hands on the “hands of the tree” (hand shaped touch pads), when this happens the 2 arteries connected to the corresponding hand will start pulsating with ‘energy’.

Jarkko built this MOD sound file player using Teensy 3.1 and resistors for analog output.  This video shows how great it sounds!

He published the complete source code on github.

Pascal Leray has designed and built an keyboard interface for an amazing classic organ that he’s built.

Main board: dedicated to contacts or Hall sensor-based organ keyboards. Direct MIDI/USB output. This board has also a standard Parallel Port, fulle PC compatible. Up to 8 keyboards/pedal/knobs. Direct USB/MIDI output.

Interface board: can receive up to 64 digital or analog inputs. To be connected to the above board.

You can read about the organ project on his web page. (It is in French, but auto translation programs seem to work it)

Update:  Here’s a link to the English version of his web page

Beat Counter counts beats and visualizes it using an 8×8 LED matrix by connecting a Teensy via MID to Ableton Live.

Ross Fish of Moffenzeef Modular has made an incredible drone synthesizer modular – The Stargazer.

STARGAZER is packed with features: dual wavetable oscillator with ninety arbitrary waveforms, two resonant lowpass filters, three wavetable LFO’s, sample rate reduction, bit rate reduction, amplitude modulation, and CMOS distortion. The expression pedal input can be used to control the speed of all three LFOs at the same time which free up your hands to control other aspects of the drone.   It’s also firmware upgradeable!

STAGAZER uses the Teensy Audio Library and is Ardunio compatible with code available on GitHub.

Eric Betts created a computer combination lock.

The lock uses the Teensy, rotary encoder, circular led bar graph, and the encoder library.  You twist the knob to the correct position as indicated by the LEDs, push down on the knob to set that value, and on the 3rd value the sequence will be checked against the first 3 bytes of EEPROM. If the combination is correct, “Secret Word” is sent as keyboard input.

The code for the project is available on GitHub.

Aaron Turner made an ECU (Engine Control Unit) decoder for his Suzuki SV650 racing bike.

Powered by a Teensy 2.0, this useful decoder replaces the stock dash on the  bike and decodes any EFI error codes, water temperature and battery voltage.

Arron has made the code and CAD/schematics available on GitHub.

Neil Merchant has made a pretty awesome dodecahedron with LEDs and infinity effect.

The dodecahedron, named Carl, uses a Teensy 3.6, OctoWS2811 adapter, SK6812 RGB LEDs, and 1-way mirrors to make the magic happen.

Neil is planning to take Carl to different festivals.  It will be making an appearance at Electric Forest, Lost Lands, and maybe Ever After Fest.

You can follow the the story of Carl’s development on this Twitter thread.

Alex Davis made Squareinator – a SN76489 Monosynth.

After being handed an old package of the SN76489 sound chip, Alex wondered if could be used as a synthesizer.  After a bit of research he was inspired to make the Squareinator.

Squareinator drives a SN76489 vintage soundchip as a monophonic
synthesizer, using all three squarewaves plus pseudo-random noise to
deliver a fat synth sound. A multi-mode 12 db/oct VCF adds additional
character and is playable at full oscillation. All synth functions are
exposed as MIDI CCs. The ATMEGA32U4 in the Teensy 2.0 allows us to use
the high-speed timer PLL to provide the 2 mHz clock required by the
SN76489 with no extra parts.

You can find the code for the project as well as a schematic on GitHub.

Loftur Jónasson built an RF Power Meter.

Lofture says that it was simple to build.  It uses a Teensy ++ to sample from an AD8307 logarithmic amplifier from Analog Devices, 200 times per second. A Rotary Encoder with a built in Pushbutton is used to navigate the various displays and to access a settings/configuration menu..

The project web page has a detailed write up and includes the code for the project.