Introduction: Digital Synth VRA8-M for Arduino Uno

    Made by ISGK Instruments


    • Monophonic Synthesizer (MIDI Sound Module) for Arduino Uno


    • Serial MIDI In (38400 bps), PWM Audio Out (Pin 6), PWM Rate: 62500 Hz
    • Sampling Rate: 15625 Hz, Bit Depth: 8 bits

    Demo Audio


    • Exhibited in Maker Faire Tokyo 2015

    Step 1: Wiring

    Required Hardware

    • Arduino Uno
    • 3.5 mm Audio Jack (or Speaker)
    • 330 (150 or more) ohm Resistor
    • Wires


    • Audio Jack L or R (or Speaker +) ---- Resistor ---- Arduino Uno Digital Pin 6
    • Audio Jack GND (or Speaker -) ---- Arduino Uno GND Pin
    • PC ----[USB Cable]---- Arduino Uno

    Additional Notes

    Step 2: Software Installation

    1. Download Source code and extract it.
    2. Download Hairless MIDI<->Serial Bridgeand extract it.
    3. Download loopMIDI and install it.

    Step 3: Start Synthesizer

    Explanation for Windows

    1. Write DigitalSynthVRA8M.ino to Arduino Uno and quit Arduino IDE.
    2. Start loopMIDI.
    3. Start hairless-midiserial.exe (Hairless MIDI<->Serial Bridge).
      • Set [File] > [Preferences] > [Baud rate] to 38400 bps.
      • Select Arduino Uno (COM*) on Serial Port.
      • Select loopMIDI Port on MIDI In.
    4. Open vra8-m-ctrl.html (VRA8-M CTRL) with Google Chrome.
      • Select loopMIDI Port on MIDI OUT.
      • Select a MIDI controller on MIDI IN (if you have it).
    5. Click (or touch) the Software Keyboard, and you can hear the sound.