3 Before you are able to compile, you'll need to install an environment for AVR development. You'll find the instructions for any OS below. If you find another/better way to set things up from scratch, please consider [making a pull request](https://github.com/qmk/qmk_firmware/pulls) with your changes!
5 ## [Build Environment Setup](wiki/Build-Environment-Setup)
7 # Customizing your keymap
9 In every keymap folder, the following files are recommended:
11 * `config.h` - the options to configure your keymap
12 * `keymap.c` - all of your keymap code, required
13 * `Makefile` - the features of QMK that are enabled, required to run `make` in your keymap folder
14 * `readme.md` - a description of your keymap, how others might use it, and explanations of features
18 The `make` command is how you compile the firmware into a .hex file, which can be loaded by a dfu programmer (like dfu-progammer via `make dfu`) or the [Teensy loader](https://www.pjrc.com/teensy/loader.html) (only used with Teensys).
20 **NOTE:** To abort a make command press `Ctrl-c`
22 The following instruction refers to these folders.
24 * The `root` (`/`) folder is the qmk_firmware folder, in which are `doc`, `keyboard`, `quantum`, etc.
25 * The `keyboard` folder is any keyboard project's folder, like `/keyboards/planck`.
26 * The `keymap` folder is any keymap's folder, like `/keyboards/planck/keymaps/default`.
27 * The `subproject` folder is the subproject folder of a keyboard, like `/keyboards/ergodox/ez`
29 ### Simple instructions for building and uploading a keyboard
31 **Most keyboards have more specific instructions in the keyboard specific readme.md file, so please check that first**
33 If the `keymap` folder contains a file name `Makefile`
35 1. Change the directory to the `keymap` folder
36 2. Run `make <subproject>-<programmer>`
38 Otherwise, if there's no `Makefile` in the `keymap` folder
40 1. Enter the `keyboard` folder
41 2. Run `make <subproject>-<keymap>-<programmer>`
43 In the above commands, replace:
45 * `<keymap>` with the name of your keymap
46 * `<subproject>` with the name of the subproject (revision or sub-model of your keyboard). For example, for Ergodox it can be `ez` or `infinity`, and for Planck `rev3` or `rev4`.
47 * If the keyboard doesn't have a subproject, or if you are happy with the default (defined in `rules.mk` file of the `keyboard` folder), you can leave it out. But remember to also remove the dash (`-`) from the command.
48 * `<programmer>` The programmer to use. Most keyboards use `dfu`, but some use `teensy`. Infinity keyboards use `dfu-util`. Check the readme file in the keyboard folder to find out which programmer to use.
49 * If you don't add `-<programmer` to the command line, the firmware will be still be compiled into a hex file, but the upload will be skipped.
51 **NOTE:** Some operating systems will refuse to program unless you run the make command as root for example `sudo make dfu`
53 ### More detailed make instruction
55 The full syntax of the `make` command is the following, but parts of the command can be left out if you run it from other directories than the `root` (as you might already have noticed by reading the simple instructions).
57 `<keyboard>-<subproject>-<keymap>-<target>`, where:
59 * `<keyboard>` is the name of the keyboard, for example `planck`
60 * Use `allkb` to compile all keyboards
61 * `<subproject>` is the name of the subproject (revision or sub-model of the keyboard). For example, for Ergodox it can be `ez` or `infinity`, and for Planck `rev3` or `rev4`.
62 * If the keyboard doesn't have any subprojects, it can be left out
63 * To compile the default subproject, you can leave it out, or specify `defaultsp`
64 * Use `allsp` to compile all subprojects
65 * `<keymap>` is the name of the keymap, for example `algernon`
66 * Use `allkm` to compile all keymaps
67 * `<target>` will be explained in more detail below.
69 **Note:** When you leave some parts of the command out, you should also remove the dash (`-`).
71 As mentioned above, there are some shortcuts, when you are in a:
73 * `keyboard` folder, the command will automatically fill the `<keyboard>` part. So you only need to type `<subproject>-<keymap>-<target>`
74 * `subproject` folder, it will fill in both `<keyboard>` and `<subproject>`
75 * `keymap` folder, then `<keyboard>` and `<keymap>` will be filled in. If you need to specify the `<subproject>` use the following syntax `<subproject>-<target>`
76 * Note in order to support this shortcut, the keymap needs its own Makefile (see the example [here](/doc/keymap_makefile_example.mk))
77 * `keymap` folder of a `subproject`, then everything except the `<target>` will be filled in
79 The `<target>` means the following
80 * If no target is given, then it's the same as `all` below
81 * `all` compiles the keyboard and generates a `<keyboard>_<keymap>.hex` file in whichever folder you run `make` from. These files are ignored by git, so don't worry about deleting them when committing/creating pull requests.
82 * `dfu`, `teensy` or `dfu-util`, compile and upload the firmware to the keyboard. If the compilation fails, then nothing will be uploaded. The programmer to use depends on the keyboard. For most keyboards it's `dfu`, but for Infinity keyboards you should use `dfu-util`, and `teensy` for standard Teensys. To find out which command you should use for your keyboard, check the keyboard specific readme. **Note** that some operating systems needs root access for these commands to work, so in that case you need to run for example `sudo make dfu`.
83 * `clean`, cleans the build output folders to make sure that everything is built from scratch. Run this before normal compilation if you have some unexplainable problems.
85 Some other targets are supported but, but not important enough to be documented here. Check the source code of the make files for more information.
87 You can also add extra options at the end of the make command line, after the target
89 * `make COLOR=false` - turns off color output
90 * `make SILENT=true` - turns off output besides errors/warnings
91 * `make VERBOSE=true` - outputs all of the gcc stuff (not interesting, unless you need to debug)
92 * `make EXTRAFLAGS=-E` - Preprocess the code without doing any compiling (useful if you are trying to debug #define commands)
94 The make command itself also has some additional options, type `make --help` for more information. The most useful is probably `-jx`, which specifies that you want to compile using more than one CPU, the `x` represents the number of CPUs that you want to use. Setting that can greatly reduce the compile times, especially if you are compiling many keyboards/keymaps. I usually set it to one less than the number of CPUs that I have, so that I have some left for doing other things while it's compiling. Note that not all operating systems and make versions supports that option.
96 Here are some examples commands
98 * `make allkb-allsp-allkm` builds everything (all keyboards, all subprojects, all keymaps). Running just `make` from the `root` will also run this.
99 * `make` from within a `keyboard` directory, is the same as `make keyboard-allsp-allkm`, which compiles all subprojects and keymaps of the keyboard. **NOTE** that this behaviour has changed. Previously it compiled just the default keymap.
100 * `make ergodox-infinity-algernon-clean` will clean the build output of the Ergodox Infinity keyboard. This example uses the full syntax and can be run from any folder with a `Makefile`
101 * `make dfu COLOR=false` from within a keymap folder, builds and uploads the keymap, but without color output.
105 There are 5 different `make` and `Makefile` locations:
108 * keyboard (`/keyboards/<keyboard>/`)
109 * keymap (`/keyboards/<keyboard>/keymaps/<keymap>/`)
110 * subproject (`/keyboards/<keyboard>/<subproject>`)
111 * subproject keymap (`/keyboards/<keyboard>/<subproject>/keymaps/<keymap>`)
113 The root contains the code used to automatically figure out which keymap or keymaps to compile based on your current directory and commandline arguments. It's considered stable, and shouldn't be modified. The keyboard one will contain the MCU set-up and default settings for your keyboard, and shouldn't be modified unless you are the producer of that keyboard. The keymap Makefile can be modified by users, and is optional. It is included automatically if it exists. You can see an example [here](/doc/keymap_makefile_example.mk) - the last few lines are the most important. The settings you set here will override any defaults set in the keyboard Makefile. **The file is required if you want to run `make` in the keymap folder.**
115 For keyboards and subprojects, the make files are split in two parts `Makefile` and `rules.mk`. All settings can be found in the `rules.mk` file, while the `Makefile` is just there for support and including the root `Makefile`. Keymaps contain just one `Makefile` for simplicity.
119 Set these variables to `no` to disable them, and `yes` to enable them.
123 This allows you to hold a key and the salt key (space by default) and have access to a various EEPROM settings that persist over power loss. It's advised you keep this disabled, as the settings are often changed by accident, and produce confusing results that makes it difficult to debug. It's one of the more common problems encountered in help sessions.
125 Consumes about 1000 bytes.
129 This gives you control over cursor movements and clicks via keycodes/custom functions.
133 This allows you to use the system and audio control key codes.
137 This allows you to print messages that can be read using [`hid_listen`](https://www.pjrc.com/teensy/hid_listen.html).
139 By default, all debug (*dprint*) print (*print*, *xprintf*), and user print (*uprint*) messages will be enabled. This will eat up a significant portion of the flash and may make the keyboard .hex file too big to program.
141 To disable debug messages (*dprint*) and reduce the .hex file size, include `#define NO_DEBUG` in your `config.h` file.
143 To disable print messages (*print*, *xprintf*) and user print messages (*uprint*) and reduce the .hex file size, include `#define NO_PRINT` in your `config.h` file.
145 To disable print messages (*print*, *xprintf*) and **KEEP** user print messages (*uprint*), include `#define USER_PRINT` in your `config.h` file.
147 To see the text, open `hid_listen` and enjoy looking at your printed messages.
149 **NOTE:** Do not include *uprint* messages in anything other than your keymap code. It must not be used within the QMK system framework. Otherwise, you will bloat other people's .hex files.
151 Consumes about 400 bytes.
155 This enables magic commands, typically fired with the default magic key combo `LSHIFT+RSHIFT+KEY`. Magic commands include turning on debugging messages (`MAGIC+D`) or temporarily toggling NKRO (`MAGIC+N`).
159 Enables your LED to breath while your computer is sleeping. Timer1 is being used here. This feature is largely unused and untested, and needs updating/abstracting.
163 This allows the keyboard to tell the host OS that up to 248 keys are held down at once (default without NKRO is 6). NKRO is off by default, even if `NKRO_ENABLE` is set. NKRO can be forced by adding `#define FORCE_NKRO` to your config.h or by binding `MAGIC_TOGGLE_NKRO` to a key and then hitting the key.
167 This enables your backlight on Timer1 and ports B5, B6, or B7 (for now). You can specify your port by putting this in your `config.h`:
169 #define BACKLIGHT_PIN B7
173 This enables MIDI sending and receiving with your keyboard. To enter MIDI send mode, you can use the keycode `MI_ON`, and `MI_OFF` to turn it off. This is a largely untested feature, but more information can be found in the `quantum/quantum.c` file.
177 This allows you to send unicode symbols via `UC(<unicode>)` in your keymap. Only codes up to 0x7FFF are currently supported.
181 This allows sending unicode symbols using `X(<unicode>)` in your keymap. Codes
182 up to 0xFFFFFFFF are supported, including emojis. You will need to maintain
183 a separate mapping table in your keymap file.
186 - Under Mac OS, only codes up to 0xFFFF are supported.
187 - Under Linux ibus, only codes up to 0xFFFFF are supported (but anything important is still under this limit for now).
189 Characters out of range supported by the OS will be ignored.
193 This allows you to interface with a Bluefruit EZ-key to send keycodes wirelessly. It uses the D2 and D3 pins.
197 This allows you output audio on the C6 pin (needs abstracting). See the [audio section](#audio-output-from-a-speaker) for more information.
201 Uses buzzer to emulate clicky switches. A cheap imitation of the Cherry blue switches. By default, uses the C6 pin, same as AUDIO_ENABLE.
205 Use this to debug changes to variable values, see the [tracing variables](#tracing-variables) section for more information.
209 This enables using the Quantum SYSEX API to send strings (somewhere?)
211 This consumes about 5390 bytes.
213 ### Customizing Makefile options on a per-keymap basis
215 If your keymap directory has a file called `Makefile` (note the filename), any Makefile options you set in that file will take precedence over other Makefile options for your particular keyboard.
217 So let's say your keyboard's makefile has `BACKLIGHT_ENABLE = yes` (or maybe doesn't even list the `BACKLIGHT_ENABLE` option, which would cause it to be off). You want your particular keymap to not have the debug console, so you make a file called `Makefile` and specify `BACKLIGHT_ENABLE = no`.
219 You can use the `doc/keymap_makefile_example.md` as a template/starting point.
221 ## The `config.h` file
223 There are 2 `config.h` locations:
225 * keyboard (`/keyboards/<keyboard>/`)
226 * keymap (`/keyboards/<keyboard>/keymaps/<keymap>/`)
228 The keyboard `config.h` is included only if the keymap one doesn't exist. The format to use for your custom one [is here](/doc/keymap_config_h_example.h). If you want to override a setting from the parent `config.h` file, you need to do this:
235 For a value of `4` for this imaginary setting. So we `undef` it first, then `define` it.
237 You can then override any settings, rather than having to copy and paste the whole thing.
239 ### Prevent stuck modifiers
241 Consider the following scenario:
243 1. Layer 0 has a key defined as Shift.
244 2. The same key is defined on layer 1 as the letter A.
245 3. User presses Shift.
246 4. User switches to layer 1 for whatever reason.
247 5. User releases Shift, or rather the letter A.
248 6. User switches back to layer 0.
250 Shift was actually never released and is still considered pressed.
252 If such situation bothers you add this to your `config.h`:
254 #define PREVENT_STUCK_MODIFIERS
256 This option uses 5 bytes of memory per every 8 keys on the keyboard
257 rounded up (5 bits per key). For example on Planck (48 keys) it uses
258 (48/8)\*5 = 30 bytes.
260 # Going beyond the keycodes
262 Aside from the [basic keycodes](https://github.com/qmk/qmk_firmware/wiki/Keycodes), your keymap can include shortcuts to common operations.
264 ## Quick aliases to common actions
266 Your keymap can include shortcuts to common operations (called "function actions" in tmk). To learn more about them check out the [Key Functions](Key-Functions) page.
268 ## Space Cadet Shift: The future, built in
270 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. Head on over to the [Space Cadet Shift](Space-Cadet-Shift) page to read about it.
272 ## The Leader key: A new kind of modifier
274 Most modifiers have to be held or toggled. But what if you had a key that indicated the start of a sequence? You could press that key and then rapidly press 1-3 more keys to trigger a macro, or enter a special layer, or anything else you might want to do. To learn more about it check out the [Leader Key](Leader-Key) page.
276 ## Tap Dance: A single key can do 3, 5, or 100 different things
278 Hit the semicolon key once, send a semicolon. Hit it twice, rapidly -- send a colon. Hit it three times, and your keyboard's LEDs do a wild dance. That's just one example of what Tap Dance can do. Read more about it on the [Tap Dance](Tap-Dance) page.
280 ## Temporarily setting the default layer
282 `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.
284 ## Macro shortcuts: Send a whole string when pressing just one key
286 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).
289 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.
292 case 0: // this would trigger when you hit a key mapped as M(0)
293 if (record->event.pressed) {
294 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
301 A macro can include the following commands:
303 * I() change interval of stroke in milliseconds.
306 * T() type key(press and release).
307 * W() wait (milliseconds).
310 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.
312 Note: Using macros to have your keyboard send passwords for you is possible, but a bad idea.
314 ### Advanced macro functions
316 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:
318 * `record->event.pressed`
320 This is a boolean value that can be tested to see if the switch is being pressed or released. An example of this is
323 if (record->event.pressed) {
330 * `register_code(<kc>);`
332 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`.
334 * `unregister_code(<kc>);`
336 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.
340 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.
344 This will turn off the layer `<n>`.
346 * `clear_keyboard();`
348 This will clear all mods and keys currently pressed.
352 This will clear all mods currently pressed.
354 * `clear_keyboard_but_mods();`
356 This will clear all keys besides the mods currently pressed.
358 * `update_tri_layer(layer_1, layer_2, layer_3);`
360 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).
362 #### Naming your macros
364 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:
374 #define EXT_PLV M(13)
377 As was done on the [Planck default keymap](/keyboards/planck/keymaps/default/keymap.c#L33-L40)
379 #### Timer functionality
381 It's possible to start timers and read values for time-specific events - here's an example:
384 static uint16_t key_timer;
385 key_timer = timer_read();
386 if (timer_elapsed(key_timer) < 100) {
387 // do something if less than 100ms have passed
389 // do something if 100ms or more have passed
393 It's best to declare the `static uint16_t key_timer;` outside of the macro block (top of file, etc).
395 #### Example: Single-key copy/paste (hold to copy, tap to paste)
397 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?
403 static uint16_t key_timer;
405 const macro_t *action_get_macro(keyrecord_t *record, uint8_t id, uint8_t opt)
409 if (record->event.pressed) {
410 key_timer = timer_read(); // if the key is being pressed, we start the timer.
412 else { // this means the key was just released, so we can figure out how long it was pressed for (tap or "held down").
413 if (timer_elapsed(key_timer) > 150) { // 150 being 150ms, the threshhold we pick for counting something as a tap.
414 return MACRO( D(LCTL), T(C), U(LCTL), END );
417 return MACRO( D(LCTL), T(V), U(LCTL), END );
427 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.
429 ## Dynamic macros: record and replay macros in runtime
431 In addition to the static macros described above, you may enable the dynamic macros which you may record while writing. They are forgotten as soon as the keyboard is unplugged. Only two such macros may be stored at the same time, with the total length of 64 keypresses (by default).
433 To enable them, first add a new element to the `planck_keycodes` enum -- `DYNAMIC_MACRO_RANGE`:
435 enum planck_keycodes {
447 Afterwards create a new layer called `_DYN`:
449 #define _DYN 6 /* almost any other free number should be ok */
451 Below these two modifications include the `dynamic_macro.h` header:
453 #include "dynamic_macro.h"`
455 Then define the `_DYN` layer with the following keys: `DYN_REC_START1`, `DYN_MACRO_PLAY1`,`DYN_REC_START2` and `DYN_MACRO_PLAY2`. It may also contain other keys, it doesn't matter apart from the fact that you won't be able to record these keys in the dynamic macros.
458 {_______, DYN_REC_START1, DYN_MACRO_PLAY1, _______, _______, _______, _______, _______, _______, _______, _______, _______},
459 {_______, DYN_REC_START2, DYN_MACRO_PLAY2, _______, _______, _______, _______, _______, _______, _______, _______, _______},
460 {_______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______},
461 {_______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______}
464 Add the following code to the very beginning of your `process_record_user()` function:
466 if (!process_record_dynamic_macro(keycode, record)) {
470 To start recording the macro, press either `DYN_REC_START1` or `DYN_REC_START2`. To finish the recording, press the `_DYN` layer button. The handler awaits specifically for the `MO(_DYN)` keycode as the "stop signal" so please don't use any fancy ways to access this layer, use the regular `MO()` modifier. To replay the macro, press either `DYN_MACRO_PLAY1` or `DYN_MACRO_PLAY2`.
472 If the LED-s start blinking during the recording with each keypress, it means there is no more space for the macro in the macro buffer. To fit the macro in, either make the other macro shorter (they share the same buffer) or increase the buffer size by setting the `DYNAMIC_MACRO_SIZE` preprocessor macro (default value: 128; please read the comments for it in the header).
474 For the details about the internals of the dynamic macros, please read the comments in the `dynamic_macro.h` header.
476 ## Additional keycode aliases for software-implemented layouts (Colemak, Dvorak, etc)
478 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:
480 #include <keymap_colemak.h>
482 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:
484 * `CM_*` for all of the Colemak-equivalent characters
485 * `DV_*` for all of the Dvorak-equivalent characters
487 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.
489 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`.
491 ## Additional language support
493 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).
497 There are three Unicode keymap definition method available in QMK:
501 Supports Unicode input up to 0xFFFF. The keycode function is `UC(n)` in
502 keymap file, where *n* is a 4 digit hexadecimal.
504 ### UNICODEMAP_ENABLE
506 Supports Unicode up to 0xFFFFFFFF. You need to maintain a separate mapping
507 table `const uint32_t PROGMEM unicode_map[] = {...}` in your keymap file.
508 The keycode function is `X(n)` where *n* is the array index of the mapping
515 Unicode input in QMK works by inputing a sequence of characters to the OS,
516 sort of like macro. Unfortunately, each OS has different ideas on how Unicode is inputted.
518 This is the current list of Unicode input method in QMK:
520 * UC_OSX: MacOS Unicode Hex Input support. Works only up to 0xFFFF. Disabled by default. To enable: go to System Preferences -> Keyboard -> Input Sources, and enable Unicode Hex.
521 * UC_LNX: Unicode input method under Linux. Works up to 0xFFFFF. Should work almost anywhere on ibus enabled distros. Without ibus, this works under GTK apps, but rarely anywhere else.
522 * UC_WIN: (not recommended) Windows built-in Unicode input. To enable: create registry key under `HKEY_CURRENT_USER\Control Panel\Input Method\EnableHexNumpad` of type `REG_SZ` called `EnableHexNumpad`, set its value to 1, and reboot. This method is not recommended because of reliability and compatibility issue, use WinCompose method below instead.
523 * UC_WINC: Windows Unicode input using WinCompose. Requires [WinCompose](https://github.com/samhocevar/wincompose). Works reliably under many (all?) variations of Windows.
525 ## Backlight Breathing
527 In order to enable backlight breathing, the following line must be added to your config.h file.
529 #define BACKLIGHT_BREATHING
531 The following function calls are used to control the breathing effect.
533 * ```breathing_enable()``` - Enable the free-running breathing effect.
534 * ```breathing_disable()``` - Disable the free-running breathing effect immediately.
535 * ```breathing_self_disable()``` - Disable the free-running breathing effect after the current effect ends.
536 * ```breathing_toggle()``` - Toggle the free-running breathing effect.
537 * ```breathing_defaults()``` - Reset the speed and brightness settings of the breathing effect.
539 The following function calls are used to control the maximum brightness of the breathing effect.
541 * ```breathing_intensity_set(value)``` - Set the brightness of the breathing effect when it is at its max value.
542 * ```breathing_intensity_default()``` - Reset the brightness of the breathing effect to the default value based on the current backlight intensity.
544 The following function calls are used to control the cycling speed of the breathing effect.
546 * ```breathing_speed_set(value)``` - Set the speed of the breathing effect - how fast it cycles.
547 * ```breathing_speed_inc(value)``` - Increase the speed of the breathing effect by a fixed value.
548 * ```breathing_speed_dec(value)``` - Decrease the speed of the breathing effect by a fixed value.
549 * ```breathing_speed_default()``` - Reset the speed of the breathing effect to the default value.
551 The following example shows how to enable the backlight breathing effect when the FUNCTION layer macro button is pressed:
554 if (record->event.pressed)
556 breathing_speed_set(3);
558 layer_on(LAYER_FUNCTION);
562 breathing_speed_set(1);
563 breathing_self_disable();
564 layer_off(LAYER_FUNCTION);
568 The following example shows how to pulse the backlight on-off-on when the RAISED layer macro button is pressed:
571 if (record->event.pressed)
573 layer_on(LAYER_RAISED);
574 breathing_speed_set(2);
576 update_tri_layer(LAYER_LOWER, LAYER_RAISED, LAYER_ADJUST);
580 layer_off(LAYER_RAISED);
581 update_tri_layer(LAYER_LOWER, LAYER_RAISED, LAYER_ADJUST);
585 ## Other firmware shortcut keycodes
587 * `RESET` - puts the MCU in DFU mode for flashing new firmware (with `make dfu`)
588 * `DEBUG` - the firmware into debug mode - you'll need hid_listen to see things
589 * `BL_ON` - turns the backlight on
590 * `BL_OFF` - turns the backlight off
591 * `BL_<n>` - sets the backlight to level *n*
592 * `BL_INC` - increments the backlight level by one
593 * `BL_DEC` - decrements the backlight level by one
594 * `BL_TOGG` - toggles the backlight
595 * `BL_STEP` - steps through the backlight levels
597 Enable the backlight from the Makefile.
599 # Custom Quantum functions
601 All of these functions are available in the `*_kb()` or `*_user()` variety. `kb` ones should only be used in the `<keyboard>/<keyboard>.c` file, and `user` ones should only be used in the `keymap.c`. The keyboard ones call the user ones - it's necessary to keep these calls to allow the keymap functions to work correctly.
603 ## `void matrix_init_*(void)`
605 This function gets called when the matrix is initiated, and can contain start-up code for your keyboard/keymap.
607 ## `void matrix_scan_*(void)`
609 This function gets called at every matrix scan, which is basically as often as the MCU can handle. Be careful what you put here, as it will get run a lot.
611 ## `bool process_record_*(uint16_t keycode, keyrecord_t *record)`
613 This function gets called on every keypress/release, and is where you can define custom functionality. The return value is whether or not QMK should continue processing the keycode - returning `false` stops the execution.
615 The `keycode` variable is whatever is defined in your keymap, eg `MO(1)`, `KC_L`, etc. and can be switch-cased to execute code whenever a particular code is pressed.
617 The `record` variable contains infomation about the actual press:
632 The conditional `if (record->event.pressed)` can tell if the key is being pressed or released, and you can execute code based on that.
634 ## `void led_set_*(uint8_t usb_led)`
636 This gets called whenever there is a state change on your host LEDs (eg caps lock, scroll lock, etc). The LEDs are defined as:
639 #define USB_LED_NUM_LOCK 0
640 #define USB_LED_CAPS_LOCK 1
641 #define USB_LED_SCROLL_LOCK 2
642 #define USB_LED_COMPOSE 3
643 #define USB_LED_KANA 4
646 and can be tested against the `usb_led` with a conditional like `if (usb_led & (1<<USB_LED_CAPS_LOCK))` - if this is true, you can turn your LED on, otherwise turn it off.
648 # Modding your keyboard
650 ## Audio output from a speaker
652 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.
654 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](/keyboards/planck/keymaps/default/keymap.c). Here are the important bits:
660 Then, lower down the file:
663 float tone_startup[][2] = {
672 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.
674 Then, we have this chunk:
677 float tone_qwerty[][2] = SONG(QWERTY_SOUND);
678 float tone_dvorak[][2] = SONG(DVORAK_SOUND);
679 float tone_colemak[][2] = SONG(COLEMAK_SOUND);
680 float tone_plover[][2] = SONG(PLOVER_SOUND);
681 float tone_plover_gb[][2] = SONG(PLOVER_GOODBYE_SOUND);
683 float music_scale[][2] = SONG(MUSIC_SCALE_SOUND);
684 float goodbye[][2] = SONG(GOODBYE_SOUND);
687 Wherein we bind predefined songs (from [quantum/audio/song_list.h](/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.
689 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:
692 PLAY_NOTE_ARRAY(tone_plover, false, 0); // Signature is: Song name, repeat, rest style
695 This is inside one of the macros. So when that macro executes, your keyboard plays that particular chime.
697 "Rest style" in the method signature above (the last parameter) specifies if there's a rest (a moment of silence) between the notes.
700 ## Recording And Playing back Music
701 * ```Music On``` - Turn music mode on. The default mapping is ```Lower+Upper+C```
702 * ```LCTL``` - start a recording
704 * ```LALT``` - stop recording, stop playing
705 * ```LGUI``` - play recording
706 * ```LALT``` - stop playing
707 * ```Music Off``` - Turn music mode off. The default mapping is ```Lower+Upper+V```
712 This is still a WIP, but check out `quantum/keymap_midi.c` to see what's happening. Enable from the Makefile.
714 ## Bluetooth functionality
716 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.
718 ## International Characters on Windows
720 [AutoHotkey](https://autohotkey.com) allows Windows users to create custom hotkeys among others.
722 The method does not require Unicode support in the keyboard itself but depends instead of AutoHotkey running in the background.
724 First you need to select a modifier combination that is not in use by any of your programs.
725 CtrlAltWin is not used very widely and should therefore be perfect for this.
726 There is a macro defined for a mod-tab combo `LCAG_T`.
727 Add this mod-tab combo to a key on your keyboard, e.g.: `LCAG_T(KC_TAB)`.
728 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.
730 In the default script of AutoHotkey you can define custom hotkeys.
735 The hotkeys above are for the combination CtrlAltGui and CtrlAltGuiShift plus the letter a.
736 AutoHotkey inserts the Text right of `Send, ` when this combination is pressed.
738 ## RGB Under Glow Mod
740 ![Planck with RGB Underglow](https://raw.githubusercontent.com/qmk/qmk_firmware/master/keyboards/planck/keymaps/yang/planck-with-rgb-underglow.jpg)
742 Here is a quick demo on Youtube (with NPKC KC60) (https://www.youtube.com/watch?v=VKrpPAHlisY).
744 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.
746 RGBLIGHT_ENABLE = yes
748 In order to use the underglow animation functions, you need to have `#define RGBLIGHT_ANIMATIONS` in your `config.h`.
750 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:
752 #define RGB_DI_PIN F4 // The pin your RGB strip is wired to
753 #define RGBLIGHT_ANIMATIONS // Require for fancier stuff (not compatible with audio)
754 #define RGBLED_NUM 14 // Number of LEDs
755 #define RGBLIGHT_HUE_STEP 10
756 #define RGBLIGHT_SAT_STEP 17
757 #define RGBLIGHT_VAL_STEP 17
759 You'll need to edit `RGB_DI_PIN` to the pin you have your `DI` on your RGB strip wired to.
761 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`
765 ![WS2812 Wiring](https://raw.githubusercontent.com/qmk/qmk_firmware/master/keyboards/planck/keymaps/yang/WS2812-wiring.jpg)
767 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.
769 ## PS/2 Mouse Support
771 Its possible to hook up a PS/2 mouse (for example touchpads or trackpoints) to your keyboard as a composite device.
773 There are three available modes for hooking up PS/2 devices: USART (best), interrupts (better) or busywait (not recommended).
777 Note: This is not recommended, you may encounter jerky movement or unsent inputs. Please use interrupt or USART version if possible.
782 PS2_MOUSE_ENABLE = yes
783 PS2_USE_BUSYWAIT = yes
786 In your keyboard config.h:
789 #ifdef PS2_USE_BUSYWAIT
790 # define PS2_CLOCK_PORT PORTD
791 # define PS2_CLOCK_PIN PIND
792 # define PS2_CLOCK_DDR DDRD
793 # define PS2_CLOCK_BIT 1
794 # define PS2_DATA_PORT PORTD
795 # define PS2_DATA_PIN PIND
796 # define PS2_DATA_DDR DDRD
797 # define PS2_DATA_BIT 2
801 ### Interrupt version
803 The following example uses D2 for clock and D5 for data. You can use any INT or PCINT pin for clock, and any pin for data.
808 PS2_MOUSE_ENABLE = yes
812 In your keyboard config.h:
816 #define PS2_CLOCK_PORT PORTD
817 #define PS2_CLOCK_PIN PIND
818 #define PS2_CLOCK_DDR DDRD
819 #define PS2_CLOCK_BIT 2
820 #define PS2_DATA_PORT PORTD
821 #define PS2_DATA_PIN PIND
822 #define PS2_DATA_DDR DDRD
823 #define PS2_DATA_BIT 5
825 #define PS2_INT_INIT() do { \
826 EICRA |= ((1<<ISC21) | \
829 #define PS2_INT_ON() do { \
830 EIMSK |= (1<<INT2); \
832 #define PS2_INT_OFF() do { \
833 EIMSK &= ~(1<<INT2); \
835 #define PS2_INT_VECT INT2_vect
841 To use USART on the ATMega32u4, you have to use PD5 for clock and PD2 for data. If one of those are unavailable, you need to use interrupt version.
846 PS2_MOUSE_ENABLE = yes
850 In your keyboard config.h:
854 #define PS2_CLOCK_PORT PORTD
855 #define PS2_CLOCK_PIN PIND
856 #define PS2_CLOCK_DDR DDRD
857 #define PS2_CLOCK_BIT 5
858 #define PS2_DATA_PORT PORTD
859 #define PS2_DATA_PIN PIND
860 #define PS2_DATA_DDR DDRD
861 #define PS2_DATA_BIT 2
863 /* synchronous, odd parity, 1-bit stop, 8-bit data, sample at falling edge */
864 /* set DDR of CLOCK as input to be slave */
865 #define PS2_USART_INIT() do { \
866 PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT); \
867 PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT); \
868 UCSR1C = ((1 << UMSEL10) | \
877 #define PS2_USART_RX_INT_ON() do { \
878 UCSR1B = ((1 << RXCIE1) | \
881 #define PS2_USART_RX_POLL_ON() do { \
882 UCSR1B = (1 << RXEN1); \
884 #define PS2_USART_OFF() do { \
886 UCSR1B &= ~((1 << RXEN1) | \
889 #define PS2_USART_RX_READY (UCSR1A & (1<<RXC1))
890 #define PS2_USART_RX_DATA UDR1
891 #define PS2_USART_ERROR (UCSR1A & ((1<<FE1) | (1<<DOR1) | (1<<UPE1)))
892 #define PS2_USART_RX_VECT USART1_RX_vect
898 ### Additional Settings
900 #### PS/2 mouse features
902 These enable settings supported by the PS/2 mouse protocol: http://www.computer-engineering.org/ps2mouse/
905 /* Use remote mode instead of the default stream mode (see link) */
906 #define PS2_MOUSE_USE_REMOTE_MODE
908 /* Enable the scrollwheel or scroll gesture on your mouse or touchpad */
909 #define PS2_MOUSE_ENABLE_SCROLLING
911 /* Some mice will need a scroll mask to be configured. The default is 0xFF. */
912 #define PS2_MOUSE_SCROLL_MASK 0x0F
914 /* Applies a transformation to the movement before sending to the host (see link) */
915 #define PS2_MOUSE_USE_2_1_SCALING
917 /* The time to wait after initializing the ps2 host */
918 #define PS2_MOUSE_INIT_DELAY 1000 /* Default */
921 You can also call the following functions from ps2_mouse.h
924 void ps2_mouse_disable_data_reporting(void);
926 void ps2_mouse_enable_data_reporting(void);
928 void ps2_mouse_set_remote_mode(void);
930 void ps2_mouse_set_stream_mode(void);
932 void ps2_mouse_set_scaling_2_1(void);
934 void ps2_mouse_set_scaling_1_1(void);
936 void ps2_mouse_set_resolution(ps2_mouse_resolution_t resolution);
938 void ps2_mouse_set_sample_rate(ps2_mouse_sample_rate_t sample_rate);
943 Use the following defines to change the sensitivity and speed of the mouse.
944 Note: you can also use `ps2_mouse_set_resolution` for the same effect (not supported on most touchpads).
947 #define PS2_MOUSE_X_MULTIPLIER 3
948 #define PS2_MOUSE_Y_MULTIPLIER 3
949 #define PS2_MOUSE_V_MULTIPLIER 1
954 If you're using a trackpoint, you will likely want to be able to use it for scrolling.
955 Its possible to enable a "scroll button/s" that when pressed will cause the mouse to scroll instead of moving.
956 To enable the feature, you must set a scroll button mask as follows:
959 #define PS2_MOUSE_SCROLL_BTN_MASK (1<<PS2_MOUSE_BUTTON_MIDDLE) /* Default */
962 To disable the scroll button feature:
965 #define PS2_MOUSE_SCROLL_BTN_MASK 0
968 The available buttons are:
971 #define PS2_MOUSE_BTN_LEFT 0
972 #define PS2_MOUSE_BTN_RIGHT 1
973 #define PS2_MOUSE_BTN_MIDDLE 2
976 You can also combine buttons in the mask by `|`ing them together.
978 Once you've configured your scroll button mask, you must configure the scroll button send interval.
979 This is the interval before which if the scroll buttons were released they would be sent to the host.
980 After this interval, they will cause the mouse to scroll and will not be sent.
983 #define PS2_MOUSE_SCROLL_BTN_SEND 300 /* Default */
986 To disable sending the scroll buttons:
988 #define PS2_MOUSE_SCROLL_BTN_SEND 0
991 Fine control over the scrolling is supported with the following defines:
994 #define PS2_MOUSE_SCROLL_DIVISOR_H 2
995 #define PS2_MOUSE_SCROLL_DIVISOR_V 2
1000 To debug the mouse, add `debug_mouse = true` or enable via bootmagic.
1003 /* To debug the mouse reports */
1004 #define PS2_MOUSE_DEBUG_HID
1005 #define PS2_MOUSE_DEBUG_RAW
1008 ## Safety Considerations
1010 You probably don't want to "brick" your keyboard, making it impossible
1011 to rewrite firmware onto it. Here are some of the parameters to show
1012 what things are (and likely aren't) too risky.
1014 - If your keyboard map does not include RESET, then, to get into DFU
1015 mode, you will need to press the reset button on the PCB, which
1016 requires unscrewing the bottom.
1017 - Messing with tmk_core / common files might make the keyboard
1019 - Too large a .hex file is trouble; `make dfu` will erase the block,
1020 test the size (oops, wrong order!), which errors out, failing to
1021 flash the keyboard, leaving it in DFU mode.
1022 - To this end, note that the maximum .hex file size on Planck is
1023 7000h (28672 decimal)
1026 Linking: .build/planck_rev4_cbbrowne.elf [OK]
1027 Creating load file for Flash: .build/planck_rev4_cbbrowne.hex [OK]
1030 text data bss dec hex filename
1031 0 22396 0 22396 577c planck_rev4_cbbrowne.hex
1034 - The above file is of size 22396/577ch, which is less than
1036 - As long as you have a suitable alternative .hex file around, you
1037 can retry, loading that one
1038 - Some of the options you might specify in your keyboard's Makefile
1039 consume extra memory; watch out for BOOTMAGIC_ENABLE,
1040 MOUSEKEY_ENABLE, EXTRAKEY_ENABLE, CONSOLE_ENABLE, API_SYSEX_ENABLE
1041 - DFU tools do /not/ allow you to write into the bootloader (unless
1042 you throw in extra fruitsalad of options), so there is little risk
1044 - EEPROM has around a 100000 write cycle. You shouldn't rewrite the
1045 firmware repeatedly and continually; that'll burn the EEPROM
1048 # Porting your keyboard to QMK
1050 If your keyboard is running an Atmega chip (atmega32u4 and others), it's pretty easy to get things setup for compiling your own firmware to flash onto your board. There is a `/util/new_project.sh <keyboard>` script to help get you started - you can simply pass your keyboard's name into the script, and all of the necessary files will be created. The components of each are described below.
1052 ## `/keyboards/<keyboard>/config.h`
1054 The `USB Device descriptor parameter` block contains parameters are used to uniquely identify your keyboard, but they don't really matter to the machine.
1056 Your `MATRIX_ROWS` and `MATRIX_COLS` are the numbers of rows and cols in your keyboard matrix - this may be different than the number of actual rows and columns on your keyboard. There are some tricks you can pull to increase the number of keys in a given matrix, but most keyboards are pretty straight-forward.
1058 The `MATRIX_ROW_PINS` and `MATRIX_COL_PINS` are the pins your MCU uses on each row/column. Your schematic (if you have one) will have this information on it, and the values will vary depending on your setup. This is one of the most important things to double-check in getting your keyboard setup correctly.
1060 For the `DIODE_DIRECTION`, most hand-wiring guides will instruct you to wire the diodes in the `COL2ROW` position, but it's possible that they are in the other - people coming from EasyAVR often use `ROW2COL`. Nothing will function if this is incorrect.
1062 `BACKLIGHT_PIN` is the pin that your PWM-controlled backlight (if one exists) is hooked-up to. Currently only B5, B6, and B7 are supported.
1064 `BACKLIGHT_BREATHING` is a fancier backlight feature that adds breathing/pulsing/fading effects to the backlight. It uses the same timer as the normal backlight. These breathing effects must be called by code in your keymap.
1066 `BACKLIGHT_LEVELS` is how many levels exist for your backlight - max is 15, and they are computed automatically from this number.
1068 ## `/keyboards/<keyboard>/Makefile`
1070 The values at the top likely won't need to be changed, since most boards use the `atmega32u4` chip. The `BOOTLOADER_SIZE` will need to be adjusted based on your MCU type. It's defaulted to the Teensy, since that's the most common controller. Below is quoted from the `Makefile`.
1073 # Boot Section Size in *bytes*
1074 # Teensy halfKay 512
1075 # Teensy++ halfKay 1024
1076 # Atmel DFU loader 4096
1077 # LUFA bootloader 4096
1079 OPT_DEFS += -DBOOTLOADER_SIZE=512
1082 At the bottom of the file, you'll find lots of features to turn on and off - all of these options should be set with `?=` to allow for the keymap overrides. `?=` only assigns if the variable was previously undefined. For the full documenation of these features, see the [Makefile options](#makefile-options).
1084 ## `/keyboards/<keyboard>/readme.md`
1086 This is where you'll describe your keyboard - please write as much as you can about it! Talking about default functionality/features is useful here. Feel free to link to external pages/sites if necessary. Images can be included here as well. This file will be rendered into a webpage at qmk.fm/keyboards/<keyboard>/.
1088 ## `/keyboards/<keyboard>/<keyboard>.c`
1090 This is where all of the custom logic for your keyboard goes - you may not need to put anything in this file, since a lot of things are configured automatically. All of the `*_kb()` functions are defined here. If you modify them, remember to keep the calls to `*_user()`, or things in the keymaps might not work. You can read more about the functions [here](#custom-quantum-functions-for-keyboards-and-keymaps)
1092 ## `/keyboards/<keyboard>/<keyboard>.h`
1094 Here is where you can (optionally) define your `KEYMAP` function to remap your matrix into a more readable format. With ortholinear boards, this isn't always necessary, but it can help to accomodate the dead spots on your matrix, where there are keys that take up more than one space (2u, staggering, 6.25u, etc). The example shows the difference between the physical keys, and the matrix design:
1102 { k00, k01, k02 }, \
1103 { k10, KC_NO, k11 }, \
1107 Each of the `kxx` variables needs to be unique, and usually follows the format `k<row><col>`. You can place `KC_NO` where your dead keys are in your matrix.
1111 If you are new to unit testing, then you can find many good resources on internet. However most of it is scattered around in small pieces here and there, and there's also many different opinions, so I won't give any recommendations.
1113 Instead I recommend these two books, explaining two different styles of Unit Testing in detail.
1115 * "Test Driven Development: By Example: Kent Beck"
1116 * "Growing Object-Oriented Software, Guided By Tests: Steve Freeman, Nat Pryce"
1118 If you prefer videos there are Uncle Bob's [Clean Coders Videos](https://cleancoders.com/), which unfortunately cost quite a bit, especially if you want to watch many of them. But James Shore has a free [Let's Play](http://www.jamesshore.com/Blog/Lets-Play) video series.
1120 ## Google Test and Google Mock
1121 It's possible to Unit Test your code using [Google Test](https://github.com/google/googletest). The Google Test framework also includes another component for writing testing mocks and stubs, called "Google Mock". For information how to write the actual tests, please refer to the documentation on that site.
1125 Note that Google Test and therefore any test has to be written in C++, even if the rest of the QMK codebases is written in C. This should hopefully not be a problem even if you don't know any C++, since there's quite clear documentation and examples of the required C++ features, and you can write the rest of the test code almost as you would write normal C. Note that some compiler errors which you might get can look quite scary, but just read carefully what it says, and you should be ok.
1127 One thing to remember, is that you have to append `extern "C"` around all of your C file includes.
1129 ## Adding tests for new or existing features
1131 If you want to unit test some feature, then take a look at the existing serial_link tests, in the `quantum/serial_link/tests folder`, and follow the steps below to create a similar structure.
1133 1. If it doesn't already exist, add a test subfolder to the folder containing the feature.
1134 2. Create a `testlist.mk` and a `rules.mk` file in that folder.
1135 3. Include those files from the root folder `testlist.mk`and `build_test.mk` respectively.
1136 4. Add a new name for your testgroup to the `testlist.mk` file. Each group defined there will be a separate executable. And that's how you can support mocking out different parts. Note that it's worth adding some common prefix, just like it's done for the serial_link tests. The reason for that is that the make command allows substring filtering, so this way you can easily run a subset of the tests.
1137 5. Define the source files and required options in the `rules.mk` file.
1138 * `_SRC` for source files
1139 * `_DEFS` for additional defines
1140 * `_INC` for additional include folders
1141 6. Write the tests in a new cpp file inside the test folder you created. That file has to be one of the files included from the `rules.mk` file.
1143 Note how there's several different tests, each mocking out a separate part. Also note that each of them only compiles the very minimum that's needed for the tests. It's recommend that you try to do the same. For a relevant video check out [Matt Hargett "Advanced Unit Testing in C & C++](https://www.youtube.com/watch?v=Wmy6g-aVgZI)
1145 ## Running the tests
1147 To run all the tests in the codebase, type `make test`. You can also run test matching a substring by typing `make test-matchingsubstring` Note that the tests are always compiled with the native compiler of your platform, so they are also run like any other program on your computer.
1149 ## Debugging the tests
1151 If there are problems with the tests, you can find the executable in the `./build/test` folder. You should be able to run those with GDB or a similar debugger.
1153 ## Full Integration tests
1155 It's not yet possible to do a full integration test, where you would compile the whole firmware and define a keymap that you are going to test. However there are plans for doing that, because writing tests that way would probably be easier, at least for people that are not used to unit testing.
1157 In that model you would emulate the input, and expect a certain output from the emulated keyboard.
1161 Sometimes you might wonder why a variable gets changed and where, and this can be quite tricky to track down without having a debugger. It's of course possible to manually add print statements to track it, but you can also enable the variable trace feature. This works for both for variables that are changed by the code, and when the variable is changed by some memory corruption.
1163 To take the feature into use add `VARIABLE_TRACE=x` to the end of you make command. `x` represents the number of variables you want to trace, which is usually 1.
1165 Then at a suitable place in the code, call `ADD_TRACED_VARIABLE`, to begin the tracing. For example to trace all the layer changes, you can do this
1167 void matrix_init_user(void) {
1168 ADD_TRACED_VARIABLE("layer", &layer_state, sizeof(layer_state));
1172 This will add a traced variable named "layer" (the name is just for your information), which tracks the memory location of `layer_state`. It tracks 4 bytes (the size of `layer_state`), so any modification to the variable will be reported. By default you can not specify a size bigger than 4, but you can change it by adding `MAX_VARIABLE_TRACE_SIZE=x` to the end of the make command line.
1174 In order to actually detect changes to the variables you should call `VERIFY_TRACED_VARIABLES` around the code that you think that modifies the variable. If a variable is modified it will tell you between which two `VERIFY_TRACED_VARIABLES` calls the modification happened. You can then add more calls to track it down further. I don't recommend spamming the codebase with calls. It's better to start with a few, and then keep adding them in a binary search fashion. You can also delete the ones you don't need, as each call need to store the file name and line number in the ROM, so you can run out of memory if you add too many calls.
1176 Also remember to delete all the tracing code once you have found the bug, as you wouldn't want to create a pull request with tracing code.