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.
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`:
