Multiple MIDIUSB endpoints on Atmega32u4

Using Arduino Audio
1

Hi! I have a USB MIDI device based on Arduino Micro and Atmega32u4. I would like the device to appear as multiple MIDI ports on the USB host side. Each port has different functionality on the controller so using different channels is not a preferred option.

To my (limited) understanding this is achieved by setting up multiple USB endpoints and interfaces. I tried to hack the PluggableUSB constructor in the MIDIUSB library, but it didn't work out.

My questions are:
-MIDIUSB creates 1 MIDI out and one MIDI in endpoint. How many additional MIDI endpoints can I add on a Micro, considering there are 6 available and some are used by other processes. Is there a way to list how many endpoints are available?

-Any hints on how to add MIDIUSB endpoints to the library is extremely appreciated.

Thank you!

2

Each port has different functionality on the controller

Each channel has its own set of controls.

I don’t know any way of getting multiple end points on the library.

3

Teensy supports up to 16 virtual MIDI cables. You can have a look at their implementation and the descriptors they use.

Pieter

4

PieterP:
Teensy supports up to 16 virtual MIDI cables. You can have a look at their implementation and the descriptors they use.

Thanks, that was a very useful reference! Indeed it seems that the Atmega32u4-based Teensy 2.0 does not support multiple USB MIDI cables, while higher end processors do that. It still puzzles me considering that the Atmega32u4 supports 6 endpoints according to the datasheet..