Fitting the MT32 Pi Zero HAT and configuring the software

This post will provide the information you need for setting up my Pi Zero HAT for MT32-Pi.

Note that to run MT32-Pi, a Pi Zero 2W is required. The HAT will work with a regular Pi (3 or above) but obviously the form factor is designed to go with the Zero. 

Four long screws and nuts are provided, with standoffs and washers. The standoff isn't quite long enough and so the washer goes alongside it between the boards to give the extra mm of hight. 

Don't push the HAT all the way home, that'll help with the fiddly job of fitting the washer and standoff. 

With the nuts fitted finger-tight, you may like to trim off the extra length.


If I didn't supply an SD card containing the software, then you can find that here:

See Dale's instructions for creating your SD card here:

You'll need to do some configuration of the file mt32-pi.cfg This is very easy, just open it in any notepad-style text editor.

Make sure that MIDI over USB is enabled - this should read usb = on


Enable audio via the DAC on the HAT by changing this line to read output_device = i2s


Enable the 4-button system by changing this line to read scheme = simple_buttons

This one is optional. A real MT32 responds to channels 2-9 and 10. You can alter this to an alternative channel mapping if the instrument or controller you want to use sends on channel 1. This setting makes the MT32 respond to channels 1-8 and 10.


Enable the screen on the HAT by setting this line to read type = ssd1306_i2c


The options just below that should already be correct; width = 128, height = 32, i2c_lcd_address = 3c, rotation and mirror = normal

I think everything else should be correct or not applicable. You may like to read the file and see whether there's anything else you'd like to change. But only do this after making the above changes and confirming that your HAT / MT32-Pi installation works. 

Control scheme

The 4-button control scheme works as follows:

Button 1 Switch synthesizer

Button 2 Switch MT-32 ROM or SoundFont

Button 3 Decrease volume

Button 4 Increase volume

Button 1 will switch between MT32 mode, which will use the MT32 ROM(s) that you have in your roms directory, and General MIDI mode, which uses any soundfonts that you have installed in the soundfonts directory on your card. 

When in General MIDI mode (aka soundfont mode), the second button will switch between any soundfonts that you have in your sountfonts directory. See the config file for specifying the default.

Buttons 3 & 4 are self-explanatory. Unfortunately they step the volume from 100-0 one step at a time, and there's no 'hold to go fast' option. 

Comments

Post a Comment

Popular posts from this blog

Building a Brachiograph

Image
 At Liverpool earlier this year, Andy Piper was demonstrating his brachiograph, or lolly-stick drawing robot arm. Ever since I first had my ZX81 I've been mildly curious about robotics but have never taken the plunge. More recently I've been looking at various plotter projects, even bookmarked a few. Seeing this one in real life and seeing how cheap and easy it was to build (and my boyfriend chucking some servos in my direction) finally tipped me over the edge.  This project turned out to be, as billed, the perfect gateway into robotics. It really is very simple to build and there are tutorials online, including from Andy himself . Thanks for all this Andy! Lots of hotglueing ensued. So far this has all been very robust.  To make the wiring neater, I made this little distribution board. First I screwed the Pi Zero down and found that I couldn't plug anything into it, so had to cut a little plinth for it. I'm not going to pretend that installing the software went without
Read more

e-ther 2 - Announcement and full rundown of features

Image
I'd like to announce the new and improved e-ther 2. This information is available in video form here . If you're not familiar with e-ther, then it's a small theremin-like instrument with MIDI and audio out . At first glance the differences aren't obvious and indeed the big changes to the hardware are internal.  However, I hope you'll find the list of new features as exciting as I do.  Hardware-wise, I've put the microcontroller and DAC onto the main board.  Although this increases costs (for me, not for you), there are some big advantages. Besides looking more professional, the audio module is no longer a 'buy separately' optional extra. It's incorporated and the audio jack is just there if you want it.  The audio module used to fit below the board but with the audio capability now built-in, the profile is more compact. Most of the new features are down to firmware which means that a large proportion of what I'm calling 'e-ther 2' will be
Read more

Enclosures for MIDISID

Image
 The default configuration for MIDISID  looks fine and is functional. I have fitted wooden cheeks to my own, which gives it a look and tilts the top forward, making it a little easier to use when you're sitting back from it. MIDISID was designed from the start with 'bring your own box' in mind. It's a modular design, the top and bottom parts are easily separated and connect with a 4-way jst-sh cable. In my head I saw it being used in a sloping-top case. Paul of Bad Dog Designs has come up with a different solution. It achieves the same goal - tipping the controls and screen forward. It's a 3D print in two parts. It takes zero effort to fit - MIDISID just drops in. I don't know whether he has made the design files public but  please contact him  if you're interested. Update Nov '23 The current version of MIDISID is now larger, has a tilted front and custom side supports: Owners are still being creative with enclosures. Here's a beautiful one from  @k
Read more