SENSEI – Multidimensional Sound Synthesizer

Maker, researcher, and music enthusiast Oscar Oomens created this beautiful and unusual synthesizer called the SENSEI for his bachelor’s thesis. The synth features a custom touch interface and wearable gyroscope that allow the user to “shape” sound in multiple dimensions.

The synth features a custom touch interface and wearable gyroscope that allow the user to “shape” sound in multiple dimensions. The main inputs aside from the keys are a joystick with three Force Sensitive Resistors (FSRs) on the grip that Oomens suggests provide control for new sound characteristics including: distance, form, sharpness, richness, and color. A capacitive ring around the joystick allows parameters to be locked and a gyroscopic ring attached to a bracelet allows the user to add vibrato to the touch keyboard and pitch bend segments. Users can also transpose octaves using + and – buttons towards the top of the board.

The board itself is stunning in its manufacture featuring embedded LEDs and soft silicone keys set into wood. Oscar was kind enough to share his parts list in our forum and has added some lovely photos to an Instagram album.

Social Distancing Radar

Arduino Guy, an 18-year-old Hackster intern and self-proclaimed embedded systems enthusiast, has developed a DIY social distancing radar

It can be attached to a bicycle or other anchor point to alert others when they are cycling, standing, or walking too close.

The project uses a Teensy 4.0 in combination with a SparkFun VL53L1X time of flight  sensor attached to a SG90 servo arm to register obstructions at distances between 40mm and 4 meters away. In his project which is documented with step-by-step instructions, 3D print files, and code suitable for advanced beginners, four LED dot matrix displays are programmed to send the message “U Good” when people are giving enough space or “Back Off” when they are too close to the sensor.

In a Hackster tutorial, Arduino Guy walks us through the project from hardware selection to modeling and previsualizing the moving mount in Fusion360. He also explains how a time of flight or ToF sensor, which uses pulses of light to register how far away something is, can be superior to other options like ultrasonic sensors which measure sound and are therefor slower and less accurate. Like all good engineers, he tests its effectiveness in the field during a bicycle journey and finds that people do, in fact, keep their distance.

Newton USB Keyboard Adapter

Fans of classic Apple keyboards rejoice! Jim Lombardo shared to our forum his recipe for creating a custom USB adapter that allows older keyboard models that use an 8-pin DIN input to serve as modern USB keyboards.

Jim took on the project when he found himself needing a keyboard for a custom Raspberry Pi computer he assembled. He found the perfect mini keyboard for his mini computera 10″ Apple Newton keyboardon hand in his spare parts bin but to his surprise found that no USB adapter already existed for the Newton’s 8-pin DIN F port. Naturally, he took it upon himself to engineer one.

To remap the serial data to USB, Jim uses a Teensy 2.0, a hacked 8-pin mini-DIN M/F or F/F cable to connect to the keyboard, and a USB A to mini B cable to connect the Teensy to the computer. On the software end, Jim created a nice and tidy library which translates the keyboard’s key scan code into ASCII.

As Jim mentions in his blog, the Newton keyboard was originally designed for use with the Newton PDA (Personal Digital Assistant) system which Apple produced in the late 80s and early 90s. While the system was a flop due to high cost and low performance, it did pave the way for Apple’s later multi-touch device successes like the iPhone and the iPad.

Photo by Blake Patterson from Alexandria, VA, USA – Newton and iPhone: ARM and ARM, CC BY 2.0,


Burning Man Art – 6400 LED Solar Tricycle

Burning Man art car builder Loren Carpenter has taken Teensy’s ability to drive LEDs to the next level with a solar-powered installation built around a tricycle that uses a Teensy 3.6 to drive 6,400 RGB WS2812 LEDs.

The 32 channel system is capable of outputting ~1.3 million RGB pixels per second, achieving over a 200 Hz frame rate for smooth animations. In the forum post linked above, Carpenter dives deep into the technical details, including his source code for those who want to try it out themselves.

The project was first built around a golf cart but the latest build uses a tricycle as a frame with a control box directly underneath that includes relays and battery chargers. Here you can see a video of Loren’s creation in action from a night on the playa at Burning Man in 2015.


Audio Codec Breakout Board

Teensy forum user kxmx_kaugummi has made a multi-channel audio codec breakout board for their modular synth set up using the Teensy and a Cirrus Logic CS42448.

An audio codec is a device that translates an analog audio signal into digital signals and turns digital back into analog. This gives us both an analog-to-digital converter (ADC) and digital-to-analog converter (DAC) that run off the same clock signal. The Cirrus Logic CS42448 is a popular 6 input, 8 output audio codec supported by the Teensy Audio library.

Teensy forum user kxmx_kaugummi used the Cirrus Logic CS42448 with a Teensy, breaking out the 6 input and 8 output differential audio signal pairs of the CS42448 and routing the digital signaling (TDM) and control (I2C) to the Teensy. This gives lots of audio channel in and out of Teensy, in a smaller, more modular form factor than other CS42448 boards.

You can find the schematic and bill of materials for both the Teensy 3.5/6 and the Teensy 4.0 over on kxmx_kaugummi’s EasyEDA page.

1930s Teletype with USB Interface

Hardware hacker Trammell Hudson used a Teensy and a handful of components to control a mechanical 1930s Teletype machine.

Model 15 teletype operation

Teletype machines from the 1930s are beautiful mechanical objects. Trammell Hudson was able to control one from his laptop using a Teensy and a handful of electronics components on a protoboard small enough to fit inside an Altoids tin.

Hudson has published a blog post detailing his approach and also a Flickr gallery of the project, including many close up images of the beautiful vintage mechanical Teletype machine and videos of it in action. Hudson has also published the schematics and source code for this project on his website.

This project was completed by Hudson while he was a member of NYC resistor, a hacker collective in Brooklyn, New York. The collective was founded in 2008, making NYC Resistor one of the first hackerspaces founded in the USA. The space is open to the public for workshops and weekly open days if you’re in New York and want to check it out.

Images by Trammell Hudson, shared under the CC-BY license.

Harmonicade: Arcade Button Synth

The Harmonicade is an impressive synth made of over 200 arcade buttons, a Teensy 3.6 and a lot of 3D printing.

The person behind KOOP Instruments wanted to learn to make music, but the traditional piano layout didn’t suit him. So, he started making his own range of musical midi devices, which are now all immaculately written up and shared over on the KOOP Instruments site.

The Harmonicade is a multi-channel MIDI keyboard using arcade push-buttons in a Wicki-Hayden style button layout, a musical keyboard layout based on hexagons. It uses over 200 arcade buttons feeding into a single Teensy 3.6 via two sets of DB25 connectors – an ingenious solution to his wiring problem!

As with all the other KOOP Instruments releases, the Harmonicade has been impeccably documented, including step-by-step build instructions with detailed wiring instructions, 3D modelling files, and helpfully commented code.

You can also read a write up of the Harmonicade on the Hackaday blog.