USBHostMIDI_Interface-Passthrough.ino

USBHostMIDI_Interface-Passthrough

This example demonstrates how to use the USBHostMIDI_Interface to send and receive MIDI data to and from USB MIDI devices connected to a Teensy's USB Host port.

Boards:

Teensy 3.6, Teensy 4.1

Connections

• Use a USB Host cable to connect a MIDI USB device to the Teensy. Connect the primary USB port of the Teensy to a computer.

Behavior

• All messages sent from the computer to the Teensy are forwarded to the USB MIDI device.
• All messages sent by the USB MIDI device are forwarded to the computer.

Mapping

• None

Written by PieterP, 2021-01-31
https://github.com/tttapa/Control-Surface

 
#include <Control_Surface.h>
#include <MIDI_Interfaces/USBHostMIDI_Interface.hpp>
 
// Create the ports for USB devices plugged into Teensy's 2nd USB port (via hubs)
USBHost usb;
USBHub hub{usb};
 
// USB Device MIDI (primary USB port)
USBMIDI_Interface devicemidi;
// USB Host MIDI (second USB port)
USBHostMIDI_Interface hostmidi{usb};
// Alternatively, use `USBHostMIDI_Interface_BigBuffer`
 
// Pipe to route MIDI data between two USB ports
BidirectionalMIDI_Pipe p;
 
void setup() {
  // Wait 1.5 seconds before turning on USB Host. If connected USB devices
  // use too much power, Teensy at least completes USB enumeration, which
  // makes isolating the power issue easier.
  delay(1500);
 
  hostmidi | p | devicemidi; // Connect the interfaces using a MIDI pipe
  usb.begin();               // Initialize the USB Host
  hostmidi.begin();          // Initialize the MIDI interfaces
  devicemidi.begin();
}
 
void loop() {
  // Continuously read incoming MIDI data and route it between the interfaces
  hostmidi.update();
  devicemidi.update();
}