Teensy USB MIDI - expanding PrintIncoming example

timg11 · Jul 19, 2014

Teensy USB MIDI - problems when expanding PrintIncoming example

I'm a beginner at C++, and I'm having a problem adding a new callback in the PrintIncoming example.

I added my new OnSysEx callback function like this:

Code:

void setup() {
  Serial.begin(115200);
[COLOR=#0000ff]  usbMIDI.setHandleSysEx(OnSysEx);[/COLOR]
  usbMIDI.setHandleNoteOff(OnNoteOff);
  usbMIDI.setHandleNoteOn(OnNoteOn);
  usbMIDI.setHandleVelocityChange(OnVelocityChange);
  usbMIDI.setHandleControlChange(OnControlChange);
  usbMIDI.setHandleProgramChange(OnProgramChange);
  usbMIDI.setHandleAfterTouch(OnAfterTouch);
  usbMIDI.setHandlePitchChange(OnPitchChange);
}

void loop() {
  usbMIDI.read(); // USB MIDI receive
}


[COLOR=#0000ff]void OnSysEx(byte *sxdata, word sxlength, bool sx_comp) {    // const uint8_t *data, uint16_t length, bool complete
  Serial.print("Sysex first byte ");     
  Serial.print(*sxdata, DEC);
  Serial.print(", length=");
  Serial.print(sxlength, DEC);
  if (sx_comp) {
    Serial.print(", done");
  }
  Serial.println();
}
[/COLOR]

void OnNoteOn(byte channel, byte note, byte velocity) {
  Serial.print("Note On, ch=");
  Serial.print(channel, DEC);
  Serial.print(", note=");
  Serial.print(note, DEC);
  Serial.print(", velocity=");
  Serial.print(velocity, DEC);
  Serial.println();
}

I get a compiler error on the first line:
usbMIDI.setHandleSysEx(OnSysEx);

that says:

Code:

  This report would have more information with
  "Show verbose output during compilation"
  enabled in File > Preferences.
Arduino: 1.0.5-r2 (Windows 7), Board: "Teensy 3.1"
PrintIncomingSX.ino: In function 'void setup()':
PrintIncomingSX:13: error: invalid conversion from 'void (*)(byte*, word, bool) {aka void (*)(unsigned char*, unsigned int, bool)}' to 'void (*)(const uint8_t*, uint16_t, bool) {aka void (*)(const unsigned char*, short unsigned int, bool)}' [-fpermissive]
In file included from C:\Program Files\Arduino\hardware\teensy\cores\teensy3/WProgram.h:28:0,
                 from C:\Program Files\Arduino\hardware\teensy\cores\teensy3/Arduino.h:1,
                 from PrintIncomingSX.ino:11:
C:\Program Files\Arduino\hardware\teensy\cores\teensy3/usb_midi.h:168:21: error:   initializing argument 1 of 'void usb_midi_class::setHandleSysEx(void (*)(const uint8_t*, uint16_t, bool))' [-fpermissive]

I don't understand how I need to declare the callback, since the other handlers used different parameters. For example,

Code:

void OnNoteOn(byte channel, byte note, byte velocity)

and in usb_midi.h it is

Code:

extern void (*usb_midi_handleNoteOn)(uint8_t ch, uint8_t note, uint8_t vel);

timg11 · Jul 20, 2014

The answer was buried in the error message - the correct types were hinted after the "aka".
I got it to compile by declaring like this:

Code:

void OnSysEx(const unsigned char* sxdata, short unsigned int sxlength, bool sx_comp) {

Teensy USB MIDI - expanding PrintIncoming example

timg11

Member

timg11

Member