Your keyboard can make sounds! If you've got a Planck, Preonic, or basically any keyboard that allows access to the C6 port, 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.
The audio code lives in [quantum/audio/audio.h](https://github.com/qmk/qmk_firmware/blob/master/quantum/audio/audio.h) and in the other files in the audio directory. It's enabled by default on the Planck [stock keymap](https://github.com/qmk/qmk_firmware/blob/master/keyboards/planck/keymaps/default/keymap.c). Here are the important bits:
Wherein we bind predefined songs (from [quantum/audio/song_list.h](https://github.com/qmk/qmk_firmware/blob/master/quantum/audio/song_list.h)) into named variables. This is one optimization that helps save on memory: These songs only take up memory when you reference them in your keymap, because they're essentially all preprocessor directives.
So now you have something called `tone_plover` for example. How do you make it play the Plover tune, then? If you look further down the keymap, you'll see this:
```
PLAY_NOTE_ARRAY(tone_plover, false, 0); // Signature is: Song name, repeat, rest style
```
This is inside one of the macros. So when that macro executes, your keyboard plays that particular chime.
"Rest style" in the method signature above (the last parameter) specifies if there's a rest (a moment of silence) between the notes.
## Recording And Playing back Music
* ```Music On``` - Turn music mode on. The default mapping is ```Lower+Upper+C```
* ```LCTL``` - start a recording
* play some tones
* ```LALT``` - stop recording, stop playing
* ```LGUI``` - play recording
* ```LALT``` - stop playing
* ```Music Off``` - Turn music mode off. The default mapping is ```Lower+Upper+V```
## MIDI functionalty
This is still a WIP, but check out `quantum/keymap_midi.c` to see what's happening. Enable from the Makefile.
## Bluetooth functionality
This requires [some hardware changes](https://www.reddit.com/r/MechanicalKeyboards/comments/3psx0q/the_planck_keyboard_with_bluetooth_guide_and/?ref=search_posts), but can be enabled via the Makefile. The firmware will still output characters via USB, so be aware of this when charging via a computer. It would make sense to have a switch on the Bluefruit to turn it off at will.
## RGB Under Glow Mod
Here is a quick demo on Youtube (with NPKC KC60) (https://www.youtube.com/watch?v=VKrpPAHlisY).
For this mod, you need an unused pin wiring to DI of WS2812 strip. After wiring the VCC, GND, and DI, you can enable the underglow in your Makefile.
RGBLIGHT_ENABLE = yes
In order to use the underglow animation functions, you need to have `#define RGBLIGHT_ANIMATIONS` in your `config.h`.
Please add the following options into your config.h, and set them up according your hardware configuration. These settings are for the `F4` pin by default:
#define RGB_DI_PIN F4 // The pin your RGB strip is wired to
#define RGBLIGHT_ANIMATIONS // Require for fancier stuff (not compatible with audio)
#define RGBLED_NUM 14 // Number of LEDs
#define RGBLIGHT_HUE_STEP 10
#define RGBLIGHT_SAT_STEP 17
#define RGBLIGHT_VAL_STEP 17
You'll need to edit `RGB_DI_PIN` to the pin you have your `DI` on your RGB strip wired to.
The firmware supports 5 different light effects, and the color (hue, saturation, brightness) can be customized in most effects. To control the underglow, you need to modify your keymap file to assign those functions to some keys/key combinations. For details, please check this keymap. `keyboards/planck/keymaps/yang/keymap.c`
Please note the USB port can only supply a limited amount of power to the keyboard (500mA by standard, however, modern computer and most usb hubs can provide 700+mA.). According to the data of NeoPixel from Adafruit, 30 WS2812 LEDs require a 5V 1A power supply, LEDs used in this mod should not more than 20.
## PS/2 Mouse Support
Its possible to hook up a PS/2 mouse (for example touchpads or trackpoints) to your keyboard as a composite device.
To hook up a Trackpoint, you need to obtain a Trackpoint module (i.e. harvest from a Thinkpad keyboard), identify the function of each pin of the module, and make the necessary circuitry between controller and Trackpoint module. For more information, please refer to [Trackpoint Hardware](https://deskthority.net/wiki/TrackPoint_Hardware) page on Deskthority Wiki.
