DU-INO: The ultimate synthesizer module and Arduino shield

DU-INO is a Eurorack synthesizer module and Arduino shield from Detroit Underground that can become anything you want it to be.

If you’re feeling verbose, call DU-INO a compact programmable digital-analog function platform. With 14 total configurable I/O, using precision ADC and DAC circuits and an analog computer, a vast array of functions are possible. A graphical OLED display and various tactile inputs offer a rich user interface.

It’s essentially the ultimate Eurorack Arduino shield. Supplying your own Arduino (or other shield-compatible microcontroller board), you can select from our growing library of functions, or use our full-featured open-source Arduino library to write your own!

Just a few of the myriad A to Z functions to which the DU-INO hardware and software lends itself include arpeggiators, 8-bit oscillators, clock sources and modulators, delays, envelope generators, function generators, glitch effects, harmonic generators, inverters, jack routers, key shifters, LFOs, MIDI interfaces, noise sources, oscilloscopes, parameter storage, quantizers, randomizers, sequencers, transports, utilities of all sorts, VCAs, waveshapers… and more!

And, did I mention that they can talk to each other (and other expansion modules) over I2C?

Hardware features include:

  • A 128 x 64 OLED display with fast SPI communication
  • An encoder with continuous rotation, click, double-click, and hold actions
  • Two pushbuttons connected to GT3 and GT4 input norms
  • Four gate/trigger jacks (GT1-4) connected to individual Arduino digital pins, configurable as outputs or buffered inputs, including two (GT3 & GT4) connected to the hardware interrupt pins
  • Four protected full-range CV inputs (CVI1-4) scaled and connected to 12-bit ADC hardware (with precision external voltage reference) in the Arduino, normed to the associated potentiometers
  • Four buffered full-range CV outputs (CVO1-4) generated from 12-bit DACs and precisely calibrated via 25-turn potentiometers
  • Four-quadrant analog multiplier (AD633) with each quadrant input configurable to the corresponding CV input or output, plus an offset input, for a huge variety of analog possibilities
  • Hardware I2C breakout for communication between DU-INOs or with expansion modules
  • A programming switch allowing the Arduino to be programmed in-circuit
  • Stiff 20mm header pins in the standard Arduino shield form factor
  • Protected 10-pin Eurorack power input (approx. 140mA/30mA draw on +/-12VDC rails)

Software Library:

You can use DU-INO with any Arduino-compatible microcontroller or FPGA board (and there are a lot of them out there), but their open source library is designed to work with the Arduino Uno 8-bit AVR boards.

At present, the following modules are implemented:

  • Core function module, providing a base for any kind of function
  • MCP4922 DAC driver (used by core function module)
  • Click encoder driver (used by core function module)
  • SH1106 OLED display driver, with graphics functions and font library
  • GUI widget module, with display and interaction primitives
  • EEPROM parameter saving and loading widget module
  • Clock module, for functions requiring clock sync
  • DSP module, for filters and other signal processing
  • Musical scale module, for functions dealing with musical notes
  • These modules provide programmer-friendly functions to interact with all of the DU-INO hardware

You can back this now via Kickstarter.

About the author

Director and DJ, Ian French (Naif) is passionate about every genre of music from Breakbeat, to Drum & Bass, to Techno and Progressive House. If he was to describe his preferred style of music he would probably describe it simply as electronic music. Besides his love for music and DJing his other passions are fine cuisine, wine, and travel.