Digital Synth VRA8-N for Arduino Uno

Made by ISGK Instruments

• https://github.com/risgk/digital-synth-vra8-n
• https://risgk.github.io/

Releases

• https://github.com/risgk/digital-synth-vra8-n/releases/tag/v2.5.1 (Jun. 5, 2021)
• https://github.com/risgk/digital-synth-vra8-n/releases/tag/v2.4.4 (Dec. 29, 2019)
• https://github.com/risgk/digital-synth-vra8-n/releases/tag/v1.2.1 (Feb. 3, 2019)
• https://github.com/risgk/digital-synth-vra8-n/releases/tag/v1.0.0 (Jul. 21, 2018)

Concept

• Monophonic Synthesizer (MIDI Sound Module) for Arduino Uno

Features

• Serial MIDI In (38.4 kbps)
• PWM Audio Out (Pin 6, Unipolar, Line Level), PWM Rate: 62.5 kHz
• Sampling Rate: 31.25 kHz, Bit Depth: 8 bits

Demo Audio

• SoundCloud https://soundcloud.com/risgk/sets/digital-synth-vra8-n

• YouTube

Notes

• Exhibited in Maker Faire Tokyo 2018, Ogaki Mini Maker Faire 2018, Maker Faire Kyoto 2019

VRA8 Series

• Digital Synth VRA8-Px https://www.instructables.com/id/Digital-Synth-VRA8-Px-for-Arduino-Uno/

Step 1: Wiring

Required Hardware

• A1: Arduino Uno
• U1: 3.5 mm Audio Jack
• R1: 100 ohm Resistor
• R2: 100 ohm Resistor
• C1: 100 nF Capacitor
• Wires

Wiring

• See the image

Step 2: Software Installation

1. Download Source code and extract it.
   • From https://github.com/risgk/digital-synth-vra8-n/releases/latest
2. Download Hairless MIDI<->Serial Bridge and extract it.
   • From https://projectgus.github.io/hairless-midiserial/
3. Download loopMIDI and install it.
   • From https://www.tobias-erichsen.de/software/loopmidi.html

Step 3: Start Synthesizer

Explanation for Windows

1. Write DigitalSynthVRA8N.ino to Arduino Uno and quit Arduino IDE.
   • CAUTION: We strongly recommend Arduino IDE 1.8.5, more precisely Arduino AVR Boards core 1.6.20
2. Start loopMIDI.
3. Start hairless-midiserial.exe (Hairless MIDI<->Serial Bridge).
   • Select Arduino Uno (COM*) on Serial Port.
   • Select loopMIDI Port on MIDI In.
   • Set [File] > [Preferences] > [Baud rate] to 38400 bps.
4. Open vra8-n-ctrl.html (VRA8-N CTRL) with Google Chrome.
   • Select a MIDI controller on MIDI IN (if you have it).
   • Select loopMIDI Port on MIDI OUT.
5. Click (or touch) the Software Keyboard, and you can hear the sound.