Mazan is a simple Raspberry pico based MIDI-USB Interface.
Without any surprise, it does 2 things:
- it receives MIDI commands from a MIDI device and send them to your computer via USB
- it receives MIDI commands from your computer via USB and send them to a MIDI device
This project is based on the Adafruit MIDI featherwing, you can either use that module or build it yourself following this guide.
To do it yourself, you'll need:
- 1x Raspberry pico (or RP2040-zero for smaller factor)
- 1x H11L1 optocoupler
- 2x MIDI DIN 5 pins connector (or stereo/TRS jack or both depending on your preferences)
- 2x 2.2kΩ resistor
- 1x 470Ω resistor
- 1x 220Ω resistor
- 1x 33Ω resistor
- 1x 10Ω resistor
- 2x LED
- 1x 1N4148 diode
Download FlashNuke.
Connect your raspberry pico to your computer while holding the boot button pressed.
Copy/paste the file named flash_nuke.uf2 on the raspberry pico drive, it will completely erase what's on your raspberry pico and automatically eject and re-mount it.
Download the latest version of CircuitPython (v9.0.5 at time of writing) and extract the zip content.
Connect your raspberry pico to your computer while holding the boot button pressed.
Copy/paste the CircuitPython firmware (file named adafruit-circuitpython-raspberry_pi_pico-en_US-9.0.5.uf2 in my case) on the raspberry pico drive, it will automatically eject and re-mount.
Copy the code from code.py in this repository.
Open the file named code.py on your raspberry pico and replace its content with the code you just copied.
Reset the raspberry pico.
You're done.
You can use tools like MIDIView to check the messages coming from any USB MIDI interface, it helps to see if the MIDI IN part is working.
You can use tools like VMPK, a virtual MIDI piano keyboard to send commands from your computer to a MIDI device connected to any USB MIDI interface, it helps to see if the MIDI OUT part is working.
If either of the MIDI connections is not working, try switching the connector cables, sometimes it really is that easy.