Description

The MIDI 1-to-8 module is a compact and versatile MIDI splitter/multiple built around an Arduino Nano micro controller. It features open-source firmware, allowing for complete customization and flexibility through various sketches (programs). This module can actively filter and process MIDI messages, making it a powerful tool for complex MIDI setups.

Key Features

• 1 Input, 8 Outputs: Splits, relays and filters MIDI input messages into eight independent MIDI outputs.
• Based on Arduino Nano and open source firmware.
• Low latency: below 1 ms
• TRS connectors type A, following MIDI TRS standard.
• Compact Design: Only 4HP wide, designed for easy integration into Eurorack systems.

In details

The MIDI 1-to-8 module is a DIY module: You must edit and upload a sketch (Arduino code) into the micro controller. Different demonstration sketches can be found on GitHub: https://github.com/dhaillant/midi1to8. Download a sketch, edit to fit your needs and upload using the Arduino EDI.

Connect your incoming MIDI/TRS cable to "IN" socket. This cable can originate from a keyboard, a computer or any MIDI device. Then, simply connect all your MIDI/TRS modules to the various outputs.

A typical scenario is to plug in port "IN" a cable from your computer audio interface or your MIDI keyboard, and send the filtered MIDI messages to several MIDI-to-CV modules to drive different synth voices, as well as to a MIDI8d module to control drums, etc.

Possible ideas and improvements

With this module, since the code is open source, you can go beyond simply splitting and copying MIDI messages. You can also modify and enhance them in creative ways. Here are some ideas for customization and advanced functionality:

Message Modification:

• Transpose: Shift the pitch of incoming MIDI notes up or down by a specified interval.
• Mute: Block specific MIDI messages (e.g., note on/off, control changes) based on user-defined rules.
• Modulate: Apply modulation to CC, velocity etc.

Keyboard Splitting:

• Split your MIDI keyboard into multiple zones, each sending messages to different MIDI channels or instruments. Example: Play bass on the lower half of your keyboard and lead synth on the upper half.

Channel Routing:

• Route incoming MIDI messages to specific outputs based on their channel. Example: Send channel 1 to output #1, channel 2 to output #2, etc.

Custom Filtering:

• Filter MIDI messages by type (e.g., note on/off, control change, program change) or channel. Example: Block all control change messages while allowing note messages to pass through.

Advanced Features:

• Implement MIDI clock distribution to synchronize multiple devices.
• Add custom arpeggiators or step sequencers for creative performance options...

What's in the package

Several options are available:

• PCB set, with pre-assembled SMD components, and front panel (THT components and Arduino not provided)
• Full kit (PCB set, front panel and all the THT components, including the Arduino Nano)
• Assembled and tested mudule, with Arduino pre-programmed with default sketch

About the PCB set

The module is made of 2 PCBs and a front panel:

• the Front PCB supporting all the jack connectors
• the Rear PCB supporting the Arduino Nano and the power input.

The boards come with pre-assembled SMD components. The only remaining components to solder are the Through Hole ones.

About the THT components

The remaining components to solder are:

• The stereo jack connectors,
• the opto-coupler and its socket,
• the 10-pin power connector,
• and the Arduino Nano and its sockets.

The MIDI jacks are Stereo (TRS type A) connector.

Further documentation

• Schematics and documentation can be found at https://www.davidhaillant.com/midi-1-to-8/
• Open source firmware are located here: https://github.com/dhaillant/midi1to8