Retrieve port information over USB

[Splines]

Access MIDI Ports

I'm trying to connect my ESP8266 Node MCU to my keyboard Yamaha Tyros 3. The latter offers two different MIDI ports (reference manual, p. 116). I didn't find anything about connecting to specific MIDI ports neither in this GitHub repo, nor the Arduino MIDI Library Documentation. I try to do something as described here in the RtMidiTutorial under the header Probing Ports / Devices where they retrieve a list of available ports and their respective names. The MidiUSB example didn't work for me. I try to light up the inbuilt LED whenever the NodeMCU receives a Note_ON message from the keyboard, but it's not working. And I don't really know how I can debug this when I use the micro USB to connect to the keyboard...

Documentation for MIDI_CREATE_INSTANCE()?

Is there any documentation on MIDI_CREATE_INSTANCE()? In the examples, I've seen that you are supposed to pass HardwareSerial and SerialUSB. How do they relate to the MIDI ports? SerialUSB is something like "COM5", right?

static const unsigned sUsbTransportBufferSize = 16;
typedef midi::UsbTransport<sUsbTransportBufferSize> UsbTransport;

UsbTransport sUsbTransport;

MIDI_CREATE_INSTANCE(UsbTransport, sUsbTransport, MIDI);

I also don't quite get what these lines are doing. For me - as someone from the Java and Node.js/Typescript world - it looks like you are declaring a new type named UsbTransport (with a specific buffer size that you pass in as generics) and then you declare a variable named sUsbTransport of that type but don't initialize it. How can these two things then be a hardware serial number and a serial USB number? (As you may have guessed, I'm relatively new to the C/C++-world.)

[franky47]

Hi, we're planning on releasing v5.0.0 soon, which will change the way the library works with native USB transport.

As for the C++ part, we're indeed defining a new type, but the only variable there is the buffer size, the USB port and the identifier for the device were not configurable in that version.

@lathoub, is there a way to choose which USB port to use with your transport ?

[lathoub]

The USB port selection is done by the USBMIDI library, that does most of the magic behind the scenes. Not sure for the ESP8266, I can have a look

[Splines]

@franky47 @lathoub Ok great, thank you for your quick replys. I'll take a look into USBMIDI as well and I'm looking forward to the new version v5.0.0 ;)

[franky47]

Version 5 has been released, check out the README for information on how to get started with USB MIDI 🎉

[Splines]

Wow, that's great, I'll try it out. Thank you.

[Splines]

@lathoub @franky47 Ok, I guess the NodeMCU v1.0 (ESP8266) board is not compatible with the underlying USBMIDI-library since I get the same error messages as described here (by the way, there was no error at all when I've used your v4). Sadly, I won't be able to use your library. Do you know any alternatives for the NodeMCU?

[franky47]

From what I can see in the datasheet, it's using a separate chip to translate UART to USB, so you might be able to pull it off by using HairlessMIDI on your computer, a Serial interface on the NodeMCU, which talks to the CP2102 USB chip.

The complete chain would then be:

Signal flowchart:
Your code -> Serial MIDI -> NodeMCU TX -> CP2102 -> USB -> HairlessMIDI -> computer MIDI

Hardware connections:
[ESP8266] <- UART -> [CP2102] <- USB -> [Computer]
[ -------- NodeMCU -------- ]