opensteno_qmk/docs/feature_audio.md

# Audio

Your keyboard can make sounds! If you've got a Planck, Preonic, or basically any AVR keyboard that allows access to the C6 or B5 port (`#define C6_AUDIO` and/or `#define B5_AUDIO`), you can hook up a simple speaker and make it beep. You can use those beeps to indicate layer transitions, modifiers, special keys, or just to play some funky 8bit tunes.

If you add `AUDIO_ENABLE = yes` to your `rules.mk`, there's a couple different sounds that will automatically be enabled without any other configuration:

```
STARTUP_SONG // plays when the keyboard starts up (audio.c)
GOODBYE_SONG // plays when you press the RESET key (quantum.c)
AG_NORM_SONG // plays when you press AG_NORM (quantum.c)
AG_SWAP_SONG // plays when you press AG_SWAP (quantum.c)
MUSIC_ON_SONG // plays when music mode is activated (process_music.c)
MUSIC_OFF_SONG // plays when music mode is deactivated (process_music.c)
CHROMATIC_SONG // plays when the chromatic music mode is selected (process_music.c)
GUITAR_SONG // plays when the guitar music mode is selected (process_music.c)
VIOLIN_SONG // plays when the violin music mode is selected (process_music.c)
MAJOR_SONG // plays when the major music mode is selected (process_music.c)
```

You can override the default songs by doing something like this in your `config.h`:

```c
#ifdef AUDIO_ENABLE
  #define STARTUP_SONG SONG(STARTUP_SOUND)
#endif
```

A full list of sounds can be found in [quantum/audio/song_list.h](https://github.com/qmk/qmk_firmware/blob/master/quantum/audio/song_list.h) - feel free to add your own to this list! All available notes can be seen in [quantum/audio/musical_notes.h](https://github.com/qmk/qmk_firmware/blob/master/quantum/audio/musical_notes.h).

To play a custom sound at a particular time, you can define a song like this (near the top of the file):

```c
float my_song[][2] = SONG(QWERTY_SOUND);
```

And then play your song like this:

```c
PLAY_SONG(my_song);
```

Alternatively, you can play it in a loop like this:

```c
PLAY_LOOP(my_song);
```

It's advised that you wrap all audio features in `#ifdef AUDIO_ENABLE` / `#endif` to avoid causing problems when audio isn't built into the keyboard.

## Music Mode

The music mode maps your columns to a chromatic scale, and your rows to octaves. This works best with ortholinear keyboards, but can be made to work with others. All keycodes less than `0xFF` get blocked, so you won't type while playing notes - if you have special keys/mods, those will still work. A work-around for this is to jump to a different layer with KC_NOs before (or after) enabling music mode.

Recording is experimental due to some memory issues - if you experience some weird behavior, unplugging/replugging your keyboard will fix things.

Keycodes available:

* `MU_ON` - Turn music mode on
* `MU_OFF` - Turn music mode off
* `MU_TOG` - Toggle music mode
* `MU_MOD` - Cycle through the music modes:
  * `CHROMATIC_MODE` - Chromatic scale, row changes the octave
  * `GUITAR_MODE` - Chromatic scale, but the row changes the string (+5 st)
  * `VIOLIN_MODE` - Chromatic scale, but the row changes the string (+7 st)
  * `MAJOR_MODE` - Major scale

In music mode, the following keycodes work differently, and don't pass through:

* `LCTL` - start a recording
* `LALT` - stop recording/stop playing
* `LGUI` - play recording
* `KC_UP` - speed-up playback
* `KC_DOWN` - slow-down playback

By default, `MUSIC_MASK` is set to `keycode < 0xFF` which means keycodes less than `0xFF` are turned into notes, and don't output anything. You can change this by defining this in your `config.h` like this:

    #define MUSIC_MASK keycode != KC_NO

Which will capture all keycodes - be careful, this will get you stuck in music mode until you restart your keyboard!

The pitch standard (`PITCH_STANDARD_A`) is 440.0f by default - to change this, add something like this to your `config.h`:

    #define PITCH_STANDARD_A 432.0f

You can completely disable Music Mode as well. This is useful, if you're pressed for space on your controller.  To disable it, add this to your `confid.h`:

    #define NO_MUSIC_MODE

## MIDI Functionality

This is still a WIP, but check out `quantum/keymap_midi.c` to see what's happening. Enable from the Makefile.

<!-- FIXME: this formatting needs work

## Audio

```c
#ifdef AUDIO_ENABLE
    AU_ON,
    AU_OFF,
    AU_TOG,

    #ifdef FAUXCLICKY_ENABLE
        FC_ON,
        FC_OFF,
        FC_TOG,
    #endif

    // Music mode on/off/toggle
    MU_ON,
    MU_OFF,
    MU_TOG,

    // Music voice iterate
    MUV_IN,
    MUV_DE,
#endif
```

### Midi

#if !MIDI_ENABLE_STRICT || (defined(MIDI_ENABLE) && defined(MIDI_BASIC))
    MI_ON,  // send midi notes when music mode is enabled
    MI_OFF, // don't send midi notes when music mode is enabled
#endif

MIDI_TONE_MIN,
MIDI_TONE_MAX

MI_C = MIDI_TONE_MIN,
MI_Cs,
MI_Db = MI_Cs,
MI_D,
MI_Ds,
MI_Eb = MI_Ds,
MI_E,
MI_F,
MI_Fs,
MI_Gb = MI_Fs,
MI_G,
MI_Gs,
MI_Ab = MI_Gs,
MI_A,
MI_As,
MI_Bb = MI_As,
MI_B,

MIDI_TONE_KEYCODE_OCTAVES > 1

where x = 1-5:
MI_C_x,
MI_Cs_x,
MI_Db_x = MI_Cs_x,
MI_D_x,
MI_Ds_x,
MI_Eb_x = MI_Ds_x,
MI_E_x,
MI_F_x,
MI_Fs_x,
MI_Gb_x = MI_Fs_x,
MI_G_x,
MI_Gs_x,
MI_Ab_x = MI_Gs_x,
MI_A_x,
MI_As_x,
MI_Bb_x = MI_As_x,
MI_B_x,

MI_OCT_Nx 1-2
MI_OCT_x 0-7
MIDI_OCTAVE_MIN = MI_OCT_N2,
MIDI_OCTAVE_MAX = MI_OCT_7,
MI_OCTD, // octave down
MI_OCTU, // octave up

MI_TRNS_Nx 1-6
MI_TRNS_x 0-6
MIDI_TRANSPOSE_MIN = MI_TRNS_N6,
MIDI_TRANSPOSE_MAX = MI_TRNS_6,
MI_TRNSD, // transpose down
MI_TRNSU, // transpose up

MI_VEL_x 1-10
MIDI_VELOCITY_MIN = MI_VEL_1,
MIDI_VELOCITY_MAX = MI_VEL_9,
MI_VELD, // velocity down
MI_VELU, // velocity up

MI_CHx 1-16
MIDI_CHANNEL_MIN = MI_CH1
MIDI_CHANNEL_MAX = MI_CH16,
MI_CHD, // previous channel
MI_CHU, // next channel

MI_ALLOFF, // all notes off

MI_SUS, // sustain
MI_PORT, // portamento
MI_SOST, // sostenuto
MI_SOFT, // soft pedal
MI_LEG,  // legato

MI_MOD, // modulation
MI_MODSD, // decrease modulation speed
MI_MODSU, // increase modulation speed
#endif // MIDI_ADVANCED

-->