What is it?

A Pi HAT that adds a screen and audio module (DAC) to a Raspberry Pi Zero 2W. It's designed to work with the MT32-Pi software which also makes it easy to add soundfonts for General MIDI, Roland GS, or even Yamaha XG support.

This HAT is specifically designed to take MIDI over USB from a MIDI device, using the Pi's USB socket. It has an I2C OLED screen, a PCM5102 I2S hi-fi audio module (DAC) and four buttons connected and labelled for the MT32Pi software. It may well work with other software that uses a I2C screen and PCM5102 DAC.

This is the Pi Hat only, you'll need to add your own Pi. If using a Pi Zero and MT32-Pi software then a PI Zero 2W is required. This HAT will work with a regular Pi and the MT32Pi software will work with a Pi 3 and above. See the MT32-Pi project readme (link below) for details of supported Pis.

I'll include the screws and standoffs you'll need to secure it to the Pi (pictured). I can optionally include an SD card containing the MT32-Pi software, configured for this HAT so you're ready to go.

I believe this can connect to a computer using a host-host adaptor (without the MIDI circuitry, the Pi operates over USB as a MIDI host, as does your computer). As the pictures and my videos show, it works great as a sound module for MIDI instruments and a regular MIDI keyboard.

Why did you make it?

I needed a small, portable sound module for use with my own MIDI-only instruments. Even if an instrument has its own sounds, it provides some great sounds from the MT32 and General MIDI library.

What makes it special?

It's very small, portable and gives you the controls you need to use the MT32-Pi software with a MIDI-over-USB device. The sound output is remarkably good quality, and some of the MT32 instruments sound very good indeed. In soundfont mode it'll sound as good as the soundfonts that you install. It handles velocity, pitch bend and other MIDI messages.

Use as an MT32 emulator or install your own soundfonts for General MIDI operation.