Teensy 4.1 MIDI-to-RS232C Video Mixer Interface

Overview

This project is a hardware and software solution for converting MIDI messages from a controller into RS-232C serial commands to control a Panasonic WJ-MX30 (or similar) video mixer. It enables synchronized control of both audio (via MIDI -> laptop) and video (via MIDI -> RS-232C -> mixer), making it ideal for live performance.

The project is inspired by and based on the _transcribe_ project by cyberboy666, with code improvements and simplified hardware design to fit my personal setup.

Table of Contents

• Hardware
• Software
• Acknowledgments & Credits
• Future Work
• License

Hardware

Components

Main Components

• Teensy 4.1
  Used for its USB Host capability, multiple UARTs, and robust MIDI support.
• USB Host Cable
  Connects the MIDI controller to the Teensy’s USB Host pins.
• MAX3232 Board
  Converts Teensy’s TTL serial to RS-232C voltage levels for the video mixer.

Extra Components

• USB-C Breakout
  Replaced Teensy's micro-b plug with usb-c.
• Project Enclosure
  All components mounted for plug-and-play.

Wiring Overview

• MIDI controller → USB Host cable → Teensy 4.1 USB Host pins
• Teensy Serial1 TX/RX → MAX3232 → RS232C DB9 OUT -> video mixer
• Teensy USB-C (or micro-B) → Laptop (for power and USB MIDI to DAW/audio software)

Software

Features

• USB Host MIDI Input/Output
  Receives/Sends MIDI from/to the USB port.
• 5-Pin DIN MIDI Input/Output
  Receives/Sends MIDI from/to the 5-Pin DIN MIDI IN/OUT.
• RS-232C Serial Output
  Sends mapped commands to the video mixer.
• Improved Mapping System
  Easily swap, edit, and extend MIDI-to-RS232C mappings.

Getting Started

1. Hardware
   Instructions to wire up the hardware can be found in /hardware (TODO)
2. Software
   Instructions to build and upload the software can be found in /software (TODO)
3. Edit MIDI mappings and use your MIDI controller to control both your laptop (audio) and video mixer (video)

Acknowledgments & Credits

This project is based on and inspired by the _transcribe_ project by cyberboy666.

Original Author:
cyberboy666 on GitHub

The _transcribe_ project provided the foundation for MIDI-to-serial video mixer control and many of the command mapping ideas.

Future Work

Possible improvements include:

• User-Friendly Mapping Editor
  Develop a GUI system for defining and swapping mappings.
• OLED/LED Status Display
  Show current mapping, MIDI activity, and connection status on the enclosure.
• Extended Mixer Support
  Add mappings and protocols for other video mixers or AV gear (whatever I can get my hands on).

License

This project is open source and released under the MIT License.
See LICENSE for details.

If you use, modify, or build on this project, please acknowledge both this repository and the original _transcribe_ project by cyberboy666.