Description of Change

This pull request fixes a small oversight in the USBMIDI pitch bend implementation:
There are three overloaded pitch bend functions for three different types of data: uint16_t, int16_t and double.
The actual implementation is located within the function accepting a uint16_t as the value parameter, while the other two simply convert the given data to match a uint16_t. However, the channel value, which should be passed along to the main function with the actual pitch bend implementation is ignored and unused in the int16_t function.

Functions

  // Pitch Bend Change [-8192,0,8191]
  void pitchBend(int16_t pitchBendValue, uint8_t channel = 1); // this one does not pass the channel value along
  // Pitch Bend Change [0,8192,16383]
  void pitchBend(uint16_t pitchBendValue, uint8_t channel = 1);
  // Pitch Bend Change [-1.0,0,1.0]
  void pitchBend(double pitchBendValue, uint8_t channel = 1);

I have confirmed this with the following minimal example on an ESP32 S3:

#include <Arduino.h>
#include <USB.h>
#include <USBMIDI.h>

USBMIDI MIDI;

void setup() {
  USB.begin();
  MIDI.begin();
}

void loop() {
  int16_t v = 0;
  while (true) {
    MIDI.pitchBend(v, 4); // channel 4
    if (++v >= 8191) v = -8191;
    delay(2);
  }
}

Probing this MIDI output with aseqdump shows, that the pitch bend values are being sent on channel 1 (the tool shows it as 0) instead of the specified channel 4:

 32:0   Pitch bend              0, value -6981
 32:0   Pitch bend              0, value -6980
 32:0   Pitch bend              0, value -6979
 32:0   Pitch bend              0, value -6978

This pull request aims to fix this slight oversight.

Test Scenarios

I have tested my changes on both a LOLIN S3 Mini and a full size ESP32 S3, but I otherwise don't have any USB-native ESPs. The test consists of the same code above being ran. On both devices aseqdump displayed the correct channel 4 (the tool shows it as 3):

 32:0   Pitch bend              3, value 2444
 32:0   Pitch bend              3, value 2445
 32:0   Pitch bend              3, value 2446
 32:0   Pitch bend              3, value 2447

Related links

I have just encountered this issue myself. I have not found an open issue matching this pull request.