Project Overview

This is the MIDI-8-SEQUENCER-V1.01, an Arduino Nano-based step sequencer that interfaces with Digital Audio Workstations (DAWs), MIDI clock sources, and Eurorack modular synthesizer systems. Built on an Arduino Nano, it is inspired by the Baby 8 sequencer, utilizing MIDI to control a sequence of adjustable output voltages.

Key Features

  • MIDI Synchronization: Handles MIDI clock, start, and stop commands.
  • User Interface: Two menu potentiometers set sequence length and MIDI clock division.
  • Output Control: Dual potentiometers at each step adjust pitch and velocity.
  • Circuit Design: Features diode summing networks emulating ‘Baby 8’ characteristics.
  • Visual Feedback: LEDs indicate active steps.

Technical Specifications

  • Input/Output: Integrates a 6N137 optocoupler for MIDI input; outputs control voltages through a diode-summed network.
  • Power Requirements: Operates via an external 7-12V DC input.
  • Connectivity: Standard MIDI and 3.5mm jacks for external connections.

Repository Content

Access all project files, including the Fritzing (.fzz) file and Gerber files for PCB manufacturing, at the GitHub repository:
GitHub Repository Link

Video Demo

Images and Diagrams


  • Connect to a MIDI source and Eurorack system.
  • Set sequence parameters using the potentiometers.
  • Choose playback mode to begin sequencing.
  • Adjust individual steps in ‘TUNING MODE’ for fine control.

Output Voltage Configuration

The sequencer features shorting Dupont jumper pins which allow for adjustable output voltage ranges. With the jumper in place, the output voltage range is 0-5V, suitable for Eurorack standards. When the jumper is removed, the range increases to 0-10V, accommodating modules that require higher voltage levels for operation.

Feel free to discuss, ask questions, or provide feedback about modifications and improvements.

Fritzing Parts

MIDI 8 Sequencer V1.01.fzz (351.5 KB)
TL072.fzpz (13.3 KB)
6N137.fzpz (6.4 KB)
Alpha Potentiometer Thonk .fzpz (7.1 KB)
PJ302M.fzpz (4.8 KB)
Rectifier Diode.fzpz (5.1 KB)

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