1 [![Build Status](https://travis-ci.org/jackhumbert/qmk_firmware.svg?branch=master)](https://travis-ci.org/jackhumbert/qmk_firmware)
2 # Quantum Mechanical Keyboard Firmware
4 This is a keyboard firmware based on the [tmk_keyboard firmware](http://github.com/tmk/tmk_keyboard) with some useful features for Atmel AVR controllers, and more specifically, the [OLKB product line](http://olkb.co), the [ErgoDox EZ](http://www.ergodox-ez.com) keyboard, and the [Clueboard product line](http://clueboard.co/).
6 QMK is developed and maintained by Jack Humbert of OLKB with contributions from the community, and of course, TMK. In fact, this repo used to be a fork of TMK, and we are incredibly grateful for his founding contributions to the firmware. We've had to break the fork due to purely technical reasons -- it simply became too different over time, and we've had to start refactoring some of the basic bits and pieces. We are huge fans of TMK, both the firmware and the person. :)
8 This documentation is edited and maintained by Erez Zukerman of ErgoDox EZ. If you spot any typos or inaccuracies, please [open an issue](https://github.com/jackhumbert/qmk_firmware/issues/new).
10 The OLKB product firmwares are maintained by Jack, the Ergodox EZ by Erez, and the Clueboard by [Zach White](https://github.com/skullydazed).
12 ## Documentation roadmap
14 This is not a tiny project. While this is the main Readme, there are many other files you might want to consult. Here are some points of interest:
16 * The Readme for your own keyboard: This is found under `keyboards/<your keyboards's name>/`. So for the ErgoDox EZ, it's [here](keyboard/ergodox_ez/); for the Atomic, it's [here](keyboard/atomic/) and so on.
17 * The [build guide](doc/BUILD_GUIDE.md), also mentioned in the next section. This is how you put your development environment together so you can compile the firmware.
18 * The list of possible keycodes you can use in your keymap is actually spread out in a few different places:
19 * [tmk_core/common/keycode.h](tmk_core/common/keycode.h) - the base TMK keycodes. This is the actual source file.
20 * [doc/keycode.txt](doc/keycode.txt) - an explanation of those same keycodes.
21 * [quantum/keymap_common.h](quantum/keymap_common.h) - this is where the QMK-specific aliases are all set up. Things like the Hyper and Meh key, the Leader key, and all of the other QMK innovations. These are also explained and documented below, but `keymap_common.h` is where they're actually defined.
22 * The [TMK documentation](doc/TMK_README.md). QMK is based on TMK, and this explains how it works internally.
26 * [BUILD_GUIDE.md](doc/BUILD_GUIDE.md) contains instructions to set up a build environment, build the firmware, and deploy it to a keyboard. Once your build environment has been set up, all `make` commands to actually build the firmware must be run from a folder in `keyboard/`.
27 * If you're looking to customize a keyboard that currently runs QMK or TMK, find your keyboard's directory under `keyboard/` and run the make commands from there.
28 * If you're looking to apply this firmware to an entirely new hardware project (a new kind of keyboard), you can create your own Quantum-based project by using `util/new_project.sh <project_name>`, which will create `/keyboard/<project_name>` with all the necessary components for a Quantum project.
32 You have access to a bunch of goodies! Check out the Makefile to enable/disable some of the features. Uncomment the `#` to enable them. Setting them to `no` does nothing and will only confuse future you.
34 BACKLIGHT_ENABLE = yes # Enable keyboard backlight functionality
35 MIDI_ENABLE = yes # MIDI controls
36 UNICODE_ENABLE = no # <-- This is how you disable an option, just set it to "no"
37 BLUETOOTH_ENABLE = yes # Enable Bluetooth with the Adafruit EZ-Key HID
39 ### Customizing Makefile options on a per-keymap basis
41 If your keymap directory has a file called `makefile.mk` (note the lowercase filename, and the `.mk` extension), any Makefile options you set in that file will take precedence over other Makefile options (those set for Quantum as a whole or for your particular keyboard).
43 So let's say your keyboard's makefile has `CONSOLE_ENABLE = yes` (or maybe doesn't even list the `CONSOLE_ENABLE` option, which would cause it to revert to the global Quantum default). You want your particular keymap to not have the debug console, so you make a file called `makefile.mk` and specify `CONSOLE_ENABLE = no`.
45 ### Customizing config.h on a per-keymap basis
47 If you use the ErgoDox EZ, you can make a `config_user.h` file in your keymap directory and use it to override any `config.h` settings you don't like. Anything you set there will take precedence over the global `config.h` for the ErgoDox EZ. To see an example of this, check out `keymaps/erez_experimental`.
49 ## Quick aliases to common actions
51 Your keymap can include shortcuts to common operations (called "function actions" in tmk).
53 ### Switching and toggling layers
55 `MO(layer)` - momentary switch to *layer*. As soon as you let go of the key, the layer is deactivated and you pop back out to the previous layer. When you apply this to a key, that same key must be set as `KC_TRNS` on the destination layer. Otherwise, you won't make it back to the original layer when you release the key (and you'll get a keycode sent). You can only switch to layers *above* your current layer. If you're on layer 0 and you use `MO(1)`, that will switch to layer 1 just fine. But if you include `MO(3)` on layer 5, that won't do anything for you -- because layer 3 is lower than layer 5 on the stack.
57 `OSL(layer)` - momentary switch to *layer*, as a one-shot operation. So if you have a key that's defined as `OSL(1)`, and you tap that key, then only the very next keystroke would come from layer 1. You would drop back to layer zero immediately after that one keystroke. That's handy if you have a layer full of custom shortcuts -- for example, a dedicated key for closing a window. So you tap your one-shot layer mod, then tap that magic 'close window' key, and keep typing like a boss. Layer 1 would remain active as long as you hold that key down, too (so you can use it like a momentary toggle-layer key with extra powers).
59 `LT(layer, kc)` - momentary switch to *layer* when held, and *kc* when tapped. Like `MO()`, this only works upwards in the layer stack (`layer` must be higher than the current layer).
61 `TG(layer)` - toggles a layer on or off. As with `MO()`, you should set this key as `KC_TRNS` in the destination layer so that tapping it again actually toggles back to the original layer. Only works upwards in the layer stack.
64 ### Fun with modifier keys
66 * `LSFT(kc)` - applies left Shift to *kc* (keycode) - `S(kc)` is an alias
67 * `RSFT(kc)` - applies right Shift to *kc*
68 * `LCTL(kc)` - applies left Control to *kc*
69 * `RCTL(kc)` - applies right Control to *kc*
70 * `LALT(kc)` - applies left Alt to *kc*
71 * `RALT(kc)` - applies right Alt to *kc*
72 * `LGUI(kc)` - applies left GUI (command/win) to *kc*
73 * `RGUI(kc)` - applies right GUI (command/win) to *kc*
74 * `HYPR(kc)` - applies Hyper (all modifiers) to *kc*
75 * `MEH(kc)` - applies Meh (all modifiers except Win/Cmd) to *kc*
76 * `LCAG(kc)` - applies CtrlAltGui to *kc*
78 You can also chain these, like this:
80 LALT(LCTL(KC_DEL)) -- this makes a key that sends Alt, Control, and Delete in a single keypress.
82 The following shortcuts automatically add `LSFT()` to keycodes to get commonly used symbols. Their long names are also available and documented in `/quantum/keymap_common.h`.
105 `OSM(mod)` - this is a "one shot" modifier. So let's say you have your left Shift key defined as `OSM(MOD_LSFT)`. Tap it, let go, and Shift is "on" -- but only for the next character you'll type. So to write "The", you don't need to hold down Shift -- you tap it, tap t, and move on with life. And if you hold down the left Shift key, it just works as a left Shift key, as you would expect (so you could type THE). There's also a magical, secret way to "lock" a modifier by tapping it multiple times. If you want to learn more about that, open an issue. :)
107 `MT(mod, kc)` - is *mod* (modifier key - MOD_LCTL, MOD_LSFT) when held, and *kc* when tapped. In other words, you can have a key that sends Esc (or the letter O or whatever) when you tap it, but works as a Control key or a Shift key when you hold it down.
109 These are the values you can use for the `mod` in `MT()` and `OSM()` (right-hand modifiers are not available for `MT()`):
119 These can also be combined like `MOD_LCTL | MOD_LSFT` e.g. `MT(MOD_LCTL | MOD_LSFT, KC_ESC)` which would activate Control and Shift when held, and send Escape when tapped.
121 We've added shortcuts to make common modifier/tap (mod-tap) mappings more compact:
123 * `CTL_T(kc)` - is LCTL when held and *kc* when tapped
124 * `SFT_T(kc)` - is LSFT when held and *kc* when tapped
125 * `ALT_T(kc)` - is LALT when held and *kc* when tapped
126 * `GUI_T(kc)` - is LGUI when held and *kc* when tapped
127 * `ALL_T(kc)` - is Hyper (all mods) when held and *kc* when tapped. To read more about what you can do with a Hyper key, see [this blog post by Brett Terpstra](http://brettterpstra.com/2012/12/08/a-useful-caps-lock-key/)
128 * `LCAG_T(kc)` - is CtrlAltGui when held and *kc* when tapped
129 * `MEH_T(kc)` - is like Hyper, but not as cool -- does not include the Cmd/Win key, so just sends Alt+Ctrl+Shift.
131 ### Space Cadet Shift: The future, built in
133 Steve Losh [described](http://stevelosh.com/blog/2012/10/a-modern-space-cadet/) the Space Cadet Shift quite well. Essentially, you hit the left Shift on its own, and you get an opening parenthesis; hit the right Shift on its own, and you get the closing one. When hit with other keys, the Shift key keeps working as it always does. Yes, it's as cool as it sounds.
135 To use it, use `KC_LSPO` (Left Shift, Parens Open) for your left Shift on your keymap, and `KC_RSPC` (Right Shift, Parens Close) for your right Shift.
137 The only other thing you're going to want to do is create a `makefile.mk` in your keymap directory and set the following:
140 COMMAND_ENABLE = no # Commands for debug and configuration
143 This is just to keep the keyboard from going into command mode when you hold both Shift keys at the same time.
145 ### The Leader key: A new kind of modifier
147 If you've ever used Vim, you know what a Leader key is. If not, you're about to discover a wonderful concept. :) Instead of hitting Alt+Shift+W for example (holding down three keys at the same time), what if you could hit a _sequence_ of keys instead? So you'd hit our special modifier (the Leader key), followed by W and then C (just a rapid succession of keys), and something would happen.
149 That's what `KC_LEAD` does. Here's an example:
151 1. Pick a key on your keyboard you want to use as the Leader key. Assign it the keycode `KC_LEAD`. This key would be dedicated just for this -- it's a single action key, can't be used for anything else.
152 2. Include the line `#define LEADER_TIMEOUT 300` somewhere in your keymap.c file, probably near the top. The 300 there is 300ms -- that's how long you have for the sequence of keys following the leader. You can tweak this value for comfort, of course.
153 3. Within your `matrix_scan_user` function, do something like this:
156 void matrix_scan_user(void) {
157 LEADER_DICTIONARY() {
163 unregister_code(KC_S);
165 SEQ_TWO_KEYS(KC_A, KC_S) {
167 unregister_code(KC_H);
169 SEQ_THREE_KEYS(KC_A, KC_S, KC_D) {
170 register_code(KC_LGUI);
172 unregister_code(KC_S);
173 unregister_code(KC_LGUI);
179 As you can see, you have three function. you can use - `SEQ_ONE_KEY` for single-key sequences (Leader followed by just one key), and `SEQ_TWO_KEYS` and `SEQ_THREE_KEYS` for longer sequences. Each of these accepts one or more keycodes as arguments. This is an important point: You can use keycodes from **any layer on your keyboard**. That layer would need to be active for the leader macro to fire, obviously.
181 ### Temporarily setting the default layer
183 `DF(layer)` - sets default layer to *layer*. The default layer is the one at the "bottom" of the layer stack - the ultimate fallback layer. This currently does not persist over power loss. When you plug the keyboard back in, layer 0 will always be the default. It is theoretically possible to work around that, but that's not what `DF` does.
185 ### Prevent stuck modifiers
187 Consider the following scenario:
189 1. Layer 0 has a key defined as Shift.
190 2. The same key is defined on layer 1 as the letter A.
191 3. User presses Shift.
192 4. User switches to layer 1 for whatever reason.
193 5. User releases Shift, or rather the letter A.
194 6. User switches back to layer 0.
196 Shift was actually never released and is still considered pressed.
198 If such situation bothers you add this to your `config.h`:
200 #define PREVENT_STUCK_MODIFIERS
202 This option uses 5 bytes of memory per every 8 keys on the keyboard
203 rounded up (5 bits per key). For example on Planck (48 keys) it uses
204 (48/8)\*5 = 30 bytes.
206 ### Remember: These are just aliases
208 These functions work the same way that their `ACTION_*` functions do - they're just quick aliases. To dig into all of the tmk ACTION_* functions, please see the [TMK documentation](https://github.com/jackhumbert/qmk_firmware/blob/master/doc/keymap.md#2-action).
210 Instead of using `FNx` when defining `ACTION_*` functions, you can use `F(x)` - the benefit here is being able to use more than 32 function actions (up to 4096), if you happen to need them.
212 ## Macro shortcuts: Send a whole string when pressing just one key
214 Instead of using the `ACTION_MACRO` function, you can simply use `M(n)` to access macro *n* - *n* will get passed into the `action_get_macro` as the `id`, and you can use a switch statement to trigger it. This gets called on the keydown and keyup, so you'll need to use an if statement testing `record->event.pressed` (see keymap_default.c).
217 const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt) // this is the function signature -- just copy/paste it into your keymap file as it is.
220 case 0: // this would trigger when you hit a key mapped as M(0)
221 if (record->event.pressed) {
222 return MACRO( I(255), T(H), T(E), T(L), T(L), W(255), T(O), END ); // this sends the string 'hello' when the macro executes
229 A macro can include the following commands:
231 * I() change interval of stroke in milliseconds.
234 * T() type key(press and release).
235 * W() wait (milliseconds).
238 So above you can see the stroke interval changed to 255ms between each keystroke, then a bunch of keys being typed, waits a while, then the macro ends.
240 Note: Using macros to have your keyboard send passwords for you is possible, but a bad idea.
242 ### Advanced macro functions
244 To get more control over the keys/actions your keyboard takes, the following functions are available to you in the `action_get_macro` function block:
246 * `record->event.pressed`
248 This is a boolean value that can be tested to see if the switch is being pressed or released. An example of this is
251 if (record->event.pressed) {
258 * `register_code(<kc>);`
260 This sends the `<kc>` keydown event to the computer. Some examples would be `KC_ESC`, `KC_C`, `KC_4`, and even modifiers such as `KC_LSFT` and `KC_LGUI`.
262 * `unregister_code(<kc>);`
264 Parallel to `register_code` function, this sends the `<kc>` keyup event to the computer. If you don't use this, the key will be held down until it's sent.
268 This will turn on the layer `<n>` - the higher layer number will always take priority. Make sure you have `KC_TRNS` for the key you're pressing on the layer you're switching to, or you'll get stick there unless you have another plan.
272 This will turn off the layer `<n>`.
274 * `clear_keyboard();`
276 This will clear all mods and keys currently pressed.
280 This will clear all mods currently pressed.
282 * `clear_keyboard_but_mods();`
284 This will clear all keys besides the mods currently pressed.
286 * `update_tri_layer(layer_1, layer_2, layer_3);`
288 If the user attempts to activate layer 1 AND layer 2 at the same time (for example, by hitting their respective layer keys), layer 3 will be activated. Layers 1 and 2 will _also_ be activated, for the purposes of fallbacks (so a given key will fall back from 3 to 2, to 1 -- and only then to 0).
290 #### Naming your macros
292 If you have a bunch of macros you want to refer to from your keymap, while keeping the keymap easily readable, you can just name them like so:
302 #define EXT_PLV M(13)
305 As was done on the [Planck default keymap](/keyboard/planck/keymaps/default/keymap.c#L33-L40)
307 #### Timer functionality
309 It's possible to start timers and read values for time-specific events - here's an example:
312 static uint16_t key_timer;
313 key_timer = timer_read();
314 if (timer_elapsed(key_timer) < 100) {
315 // do something if less than 100ms have passed
317 // do something if 100ms or more have passed
321 It's best to declare the `static uint16_t key_timer;` outside of the macro block (top of file, etc).
323 #### Example: Single-key copy/paste (hold to copy, tap to paste)
325 With QMK, it's easy to make one key do two things, as long as one of those things is being a modifier. :) So if you want a key to act as Ctrl when held and send the letter R when tapped, that's easy: `CTL_T(KC_R)`. But what do you do when you want that key to send Ctrl-V (paste) when tapped, and Ctrl-C (copy) when held?
331 static uint16_t key_timer;
333 const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
337 if (record->event.pressed) {
338 key_timer = timer_read(); // if the key is being pressed, we start the timer.
340 else { // this means the key was just released, so we can figure out how long it was pressed for (tap or "held down").
341 if (timer_elapsed(key_timer) > 150) { // 150 being 150ms, the threshhold we pick for counting something as a tap.
342 return MACRO( D(LCTL), T(C), U(LCTL), END );
345 return MACRO( D(LCTL), T(V), U(LCTL), END );
355 And then, to assign this macro to a key on your keyboard layout, you just use `M(0)` on the key you want to press for copy/paste.
357 ## Additional keycode aliases for software-implemented layouts (Colemak, Dvorak, etc)
359 Everything is assuming you're in Qwerty (in software) by default, but there is built-in support for using a Colemak or Dvorak layout by including this at the top of your keymap:
361 #include <keymap_colemak.h>
363 If you use Dvorak, use `keymap_dvorak.h` instead of `keymap_colemak.h` for this line. After including this line, you will get access to:
365 * `CM_*` for all of the Colemak-equivalent characters
366 * `DV_*` for all of the Dvorak-equivalent characters
368 These implementations assume you're using Colemak or Dvorak on your OS, not on your keyboard - this is referred to as a software-implemented layout. If your computer is in Qwerty and your keymap is in Colemak or Dvorak, this is referred to as a firmware-implemented layout, and you won't need these features.
370 To give an example, if you're using software-implemented Colemak, and want to get an `F`, you would use `CM_F` - `KC_F` under these same circumstances would result in `T`.
372 ## Additional language support
374 In `quantum/keymap_extras/`, you'll see various language files - these work the same way as the alternative layout ones do. Most are defined by their two letter country/language code followed by an underscore and a 4-letter abbreviation of its name. `FR_UGRV` which will result in a `ù` when using a software-implemented AZERTY layout. It's currently difficult to send such characters in just the firmware (but it's being worked on - see Unicode support).
378 You can currently send 4 hex digits with your OS-specific modifier key (RALT for OSX with the "Unicode Hex Input" layout) - this is currently limited to supporting one OS at a time, and requires a recompile for switching. 8 digit hex codes are being worked on. The keycode function is `UC(n)`, where *n* is a 4 digit hexidecimal. Enable from the Makefile.
380 ## Other firmware shortcut keycodes
382 * `RESET` - puts the MCU in DFU mode for flashing new firmware (with `make dfu`)
383 * `DEBUG` - the firmware into debug mode - you'll need hid_listen to see things
384 * `BL_ON` - turns the backlight on
385 * `BL_OFF` - turns the backlight off
386 * `BL_<n>` - sets the backlight to level *n*
387 * `BL_INC` - increments the backlight level by one
388 * `BL_DEC` - decrements the backlight level by one
389 * `BL_TOGG` - toggles the backlight
390 * `BL_STEP` - steps through the backlight levels
392 Enable the backlight from the Makefile.
394 ## Driving a speaker - audio support
396 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 have it beep. You can use those beeps to indicate layer transitions, modifiers, special keys, or just to play some funky 8bit tunes.
398 The audio code lives in [quantum/audio/audio.h](/quantum/audio/audio.h) and in the other files in the audio directory. It's enabled by default on the Planck [stock keymap](/keyboard/planck/keymaps/default/keymap.c). Here are the important bits:
404 Then, lower down the file:
407 float tone_startup[][2] = {
416 This is how you write a song. Each of these lines is a note, so we have a little ditty composed of five notes here.
418 Then, we have this chunk:
421 float tone_qwerty[][2] = SONG(QWERTY_SOUND);
422 float tone_dvorak[][2] = SONG(DVORAK_SOUND);
423 float tone_colemak[][2] = SONG(COLEMAK_SOUND);
424 float tone_plover[][2] = SONG(PLOVER_SOUND);
425 float tone_plover_gb[][2] = SONG(PLOVER_GOODBYE_SOUND);
427 float music_scale[][2] = SONG(MUSIC_SCALE_SOUND);
428 float goodbye[][2] = SONG(GOODBYE_SOUND);
431 Wherein we bind predefined songs (from [audio/song_list.h](/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.
433 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:
436 PLAY_NOTE_ARRAY(tone_plover, false, 0); // Signature is: Song name, repeat, rest style
439 This is inside one of the macros. So when that macro executes, your keyboard plays that particular chime.
441 "Rest style" in the method signature above (the last parameter) specifies if there's a rest (a moment of silence) between the notes.
445 This is still a WIP, but check out `quantum/keymap_midi.c` to see what's happening. Enable from the Makefile.
447 ## Bluetooth functionality
449 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.
451 ## International Characters on Windows
453 [AutoHotkey](https://autohotkey.com) allows Windows users to create custom hotkeys among others.
455 The method does not require Unicode support in the keyboard itself but depends instead of AutoHotkey running in the background.
457 First you need to select a modifier combination that is not in use by any of your programs.
458 CtrlAltWin is not used very widely and should therefore be perfect for this.
459 There is a macro defined for a mod-tab combo `LCAG_T`.
460 Add this mod-tab combo to a key on your keyboard, e.g.: `LCAG_T(KC_TAB)`.
461 This makes the key behave like a tab key if pressed and released immediately but changes it to the modifier if used with another key.
463 In the default script of AutoHotkey you can define custom hotkeys.
468 The hotkeys above are for the combination CtrlAltGui and CtrlAltGuiShift plus the letter a.
469 AutoHotkey inserts the Text right of `Send, ` when this combination is pressed.
471 ## RGB Under Glow Mod
473 ![Planck with RGB Underglow](https://raw.githubusercontent.com/yangliu/qmk_firmware/planck-rgb/keyboard/planck/keymaps/yang/planck-with-rgb-underglow.jpg)
475 Here is a quick demo on Youtube (with NPKC KC60) (https://www.youtube.com/watch?v=VKrpPAHlisY).
477 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.
479 RGBLIGHT_ENABLE = yes
481 Please note that the underglow is not compatible with audio output. So you cannot enable both of them at the same time.
483 Please add the following options into your config.h, and set them up according your hardware configuration. These settings are for the F4 by default:
485 #define ws2812_PORTREG PORTF
486 #define ws2812_DDRREG DDRF
487 #define ws2812_pin PF4
488 #define RGBLED_NUM 14 // Number of LEDs
489 #define RGBLIGHT_HUE_STEP 10
490 #define RGBLIGHT_SAT_STEP 17
491 #define RGBLIGHT_VAL_STEP 17
493 You'll need to edit `PORTF`, `DDRF`, and `PF4` on the first three lines to the port/pin you have your LED(s) wired to, eg for B3 change things to:
495 #define ws2812_PORTREG PORTB
496 #define ws2812_DDRREG DDRB
497 #define ws2812_pin PB3
499 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. `keyboard/planck/keymaps/yang/keymap.c`
503 ![WS2812 Wiring](https://raw.githubusercontent.com/yangliu/qmk_firmware/planck-rgb/keyboard/planck/keymaps/yang/WS2812-wiring.jpg)
505 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.
507 ## Safety Considerations
509 You probably don't want to "brick" your keyboard, making it impossible
510 to rewrite firmware onto it. Here are some of the parameters to show
511 what things are (and likely aren't) too risky.
513 - If a keyboard map does not include RESET, then, to get into DFU
514 mode, you will need to press the reset button on the PCB, which
515 requires unscrewing some bits.
516 - Messing with tmk_core / common files might make the keyboard
518 - Too large a .hex file is trouble; `make dfu` will erase the block,
519 test the size (oops, wrong order!), which errors out, failing to
521 - DFU tools do /not/ allow you to write into the bootloader (unless
522 you throw in extra fruitsalad of options), so there is little risk
524 - EEPROM has around a 100000 write cycle. You shouldn't rewrite the
525 firmware repeatedly and continually; that'll burn the EEPROM