1 files changed, 87 insertions, 44 deletions
diff --git a/docs/feature_backlight.md b/docs/feature_backlight.md
index 6a2946fd6..71f375594 100644
--- a/docs/feature_backlight.md
+++ b/docs/feature_backlight.md
@@ -6,14 +6,16 @@ QMK is able to control the brightness of these LEDs by switching them on and off
 The MCU can only supply so much current to its GPIO pins. Instead of powering the backlight directly from the MCU, the backlight pin is connected to a transistor or MOSFET that switches the power to the LEDs.
-## Usage
+## Driver configuration
 Most keyboards have backlighting enabled by default if they support it, but if it is not working for you, check that your `rules.mk` includes the following:
-```make
+```makefile
-BACKLIGHT_ENABLE = yes
+BACKLIGHT_ENABLE = software # Valid driver values are 'yes,software,no'
 ```
+See below for help on individual drivers.
 ## Keycodes
 Once enabled the following keycodes below can be used to change the backlight level.
@@ -27,8 +29,54 @@ Once enabled the following keycodes below can be used to change the backlight le
 |`BL_DEC` |Decrease the backlight level              |
 |`BL_BRTG`|Toggle backlight breathing                |
+## Backlight Functions
+|Function  |Description                                                |
+|----------|-----------------------------------------------------------|
+|`backlight_toggle()`    |Turn the backlight on or off                 |
+|`backlight_enable()`    |Turn the backlight on                        |
+|`backlight_disable()`   |Turn the backlight off                       |
+|`backlight_step()`      |Cycle through backlight levels               |
+|`backlight_increase()`  |Increase the backlight level                 |
+|`backlight_decrease()`  |Decrease the backlight level                 |
+|`backlight_level(x)`    |Sets the backlight level to specified level  |
+|`get_backlight_level()` |Return the current backlight level           |
+|`is_backlight_enabled()`|Return whether the backlight is currently on |
+### Backlight Breathing Functions
+|Function  |Description                                        |
+|----------|---------------------------------------------------|
+|`breathing_toggle()`  |Turn the backlight breathing on or off |
+|`breathing_enable()`  |Turns on backlight breathing           |
+|`breathing_disable()` |Turns off backlight breathing          |
+## Common Driver Configuration
+To change the behavior of the backlighting, `#define` these in your `config.h`:
+|Define               |Default      |Description                                                                           |
+|---------------------|-------------|--------------------------------------------------------------------------------------|
+|`BACKLIGHT_LEVELS`   |`3`          |The number of brightness levels (maximum 31 excluding off)                            |
+|`BACKLIGHT_CAPS_LOCK`|*Not defined*|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED)      |
+|`BACKLIGHT_BREATHING`|*Not defined*|Enable backlight breathing, if supported                                              |
+|`BREATHING_PERIOD`   |`6`          |The length of one backlight "breath" in seconds                                       |
+|`BACKLIGHT_ON_STATE` |`0`          |The state of the backlight pin when the backlight is "on" - `1` for high, `0` for low |
+### Backlight On State
+Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor *on* and light the LEDs, you must drive the backlight pin, connected to the gate or base, *high*.
+Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case, when the transistor is on, the pin is driven *low* instead.
+This functionality is configured at the keyboard level with the `BACKLIGHT_ON_STATE` define.
 ## AVR driver
+On AVR boards, the default driver currently sniffs the configuration to pick the best scenario. To enable it, add this to your rules.mk:
+```makefile
+BACKLIGHT_ENABLE = yes
+```
 ### Caveats
 Hardware PWM is supported according to the following table:
@@ -63,22 +111,10 @@ When both timers are in use for Audio, the backlight PWM will not use a hardware
 To change the behavior of the backlighting, `#define` these in your `config.h`:
-|Define               |Default      |Description                                                                                                  |
+|Define               |Default      |Description                                                                                                   |
-|---------------------|-------------|-------------------------------------------------------------------------------------------------------------|
+|---------------------|-------------|--------------------------------------------------------------------------------------------------------------|
-|`BACKLIGHT_PIN`      |`B7`         |The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this|
+|`BACKLIGHT_PIN`      |`B7`         |The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this |
-|`BACKLIGHT_PINS`     |*Not defined*|experimental: see below for more information                                                                 |
+|`BACKLIGHT_PINS`     |*Not defined*|experimental: see below for more information                                                                  |
-|`BACKLIGHT_LEVELS`   |`3`          |The number of brightness levels (maximum 31 excluding off)                                                   |
-|`BACKLIGHT_CAPS_LOCK`|*Not defined*|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED)                             |
-|`BACKLIGHT_BREATHING`|*Not defined*|Enable backlight breathing, if supported                                                                     |
-|`BREATHING_PERIOD`   |`6`          |The length of one backlight "breath" in seconds                                                              |
-|`BACKLIGHT_ON_STATE` |`0`          |The state of the backlight pin when the backlight is "on" - `1` for high, `0` for low                        |
-### Backlight On State
-Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor *on* and light the LEDs, you must drive the backlight pin, connected to the gate or base, *high*.
-Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case, when the transistor is on, the pin is driven *low* instead.
-This functionality is configured at the keyboard level with the `BACKLIGHT_ON_STATE` define.
 ### Multiple backlight pins
@@ -103,7 +139,7 @@ In this way `OCRxx` essentially controls the duty cycle of the LEDs, and thus th
 The breathing effect is achieved by registering an interrupt handler for `TIMER1_OVF_vect` that is called whenever the counter resets, roughly 244 times per second.
 In this handler, the value of an incrementing counter is mapped onto a precomputed brightness curve. To turn off breathing, the interrupt handler is simply disabled, and the brightness reset to the level stored in EEPROM.
-### Software PWM Implementation
+### Timer Assisted PWM Implementation
 When `BACKLIGHT_PIN` is not set to a hardware backlight pin, QMK will use a hardware timer configured to trigger software interrupts. This time will count up to `ICRx` (by default `0xFFFF`) before resetting to 0.
 When resetting to 0, the CPU will fire an OVF (overflow) interrupt that will turn the LEDs on, starting the duty cycle.
@@ -114,9 +150,14 @@ The breathing effect is the same as in the hardware PWM implementation.
 ## ARM Driver
+While still in its early stages, ARM backlight support aims to eventually have feature parity with AVR. To enable it, add this to your rules.mk:
+```makefile
+BACKLIGHT_ENABLE = yes
+```
 ### Caveats
-Currently only hardware PWM is supported, and does not provide automatic configuration.
+Currently only hardware PWM is supported, not timer assisted, and does not provide automatic configuration.
 ?> STMF072 support is being investigated.
@@ -130,30 +171,32 @@ To change the behavior of the backlighting, `#define` these in your `config.h`:
 |`BACKLIGHT_PWM_DRIVER`  |`PWMD4`      |The PWM driver to use, see ST datasheets for pin to PWM timer mapping. Unless you are designing your own keyboard, you shouldn't need to change this|
 |`BACKLIGHT_PWM_CHANNEL` |`3`          |The PWM channel to use, see ST datasheets for pin to PWM channel mapping. Unless you are designing your own keyboard, you shouldn't need to change this|
 |`BACKLIGHT_PAL_MODE`    |`2`          |The pin alternative function to use, see ST datasheets for pin AF mapping. Unless you are designing your own keyboard, you shouldn't need to change this|
-|`BACKLIGHT_LEVELS`      |`3`          |The number of brightness levels (maximum 31 excluding off)                                                   |
-|`BACKLIGHT_CAPS_LOCK`   |*Not defined*|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED)                             |
-|`BACKLIGHT_BREATHING`   |*Not defined*|Enable backlight breathing, if supported                                                                     |
-|`BREATHING_PERIOD`      |`6`          |The length of one backlight "breath" in seconds                                                              |
-## Backlight Functions
+## Software PWM Driver
-|Function  |Description                                                |
+Emulation of PWM while running other keyboard tasks, it offers maximum hardware compatibility without extra platform configuration. The tradeoff is the backlight might jitter when the keyboard is busy. To enable, add this to your rules.mk:
-|----------|-----------------------------------------------------------|
+```makefile
-|`backlight_toggle()`    |Turn the backlight on or off                 |
+BACKLIGHT_ENABLE = software
-|`backlight_enable()`    |Turn the backlight on                        |
+```
-|`backlight_disable()`   |Turn the backlight off                       |
-|`backlight_step()`      |Cycle through backlight levels               |
-|`backlight_increase()`  |Increase the backlight level                 |
-|`backlight_decrease()`  |Decrease the backlight level                 |
-|`backlight_level(x)`    |Sets the backlight level, from 0 to          |
-|                        |`BACKLIGHT_LEVELS`                           |
-|`get_backlight_level()` |Return the current backlight level           |
-|`is_backlight_enabled()`|Return whether the backlight is currently on |
-### Backlight Breathing Functions
+### Software PWM Configuration
+To change the behavior of the backlighting, `#define` these in your `config.h`:
+|Define           |Default      |Description                                                                                                  |
+|-----------------|-------------|-------------------------------------------------------------------------------------------------------------|
+|`BACKLIGHT_PIN`  |`B7`         |The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this|
+|`BACKLIGHT_PINS` |*Not defined*|experimental: see below for more information                                                                 |
-|Function  |Description                                               |
+### Multiple backlight pins
-|----------|----------------------------------------------------------|
-|`breathing_toggle()`  |Turn the backlight breathing on or off        |
+Most keyboards have only one backlight pin which control all backlight LEDs (especially if the backlight is connected to an hardware PWM pin).
-|`breathing_enable()`  |Turns on backlight breathing                  |
+In software PWM, it is possible to define multiple backlight pins. All those pins will be turned on and off at the same time during the PWM duty cycle.
-|`breathing_disable()` |Turns off backlight breathing                 |
+This feature allows to set for instance the Caps Lock LED (or any other controllable LED) brightness at the same level as the other LEDs of the backlight. This is useful if you have mapped LCTRL in place of Caps Lock and you need the Caps Lock LED to be part of the backlight instead of being activated when Caps Lock is on.
+To activate multiple backlight pins, you need to add something like this to your user `config.h`:
+```c
+#undef BACKLIGHT_PIN
+#define BACKLIGHT_PINS { F5, B2 }
+```

diff --git a/docs/feature_backlight.md b/docs/feature_backlight.md index 6a2946fd6..71f375594 100644 --- a/docs/feature_backlight.md +++ b/docs/feature_backlight.md
@@ -6,14 +6,16 @@ QMK is able to control the brightness of these LEDs by switching them on and off
6		6
7	The MCU can only supply so much current to its GPIO pins. Instead of powering the backlight directly from the MCU, the backlight pin is connected to a transistor or MOSFET that switches the power to the LEDs.	7	The MCU can only supply so much current to its GPIO pins. Instead of powering the backlight directly from the MCU, the backlight pin is connected to a transistor or MOSFET that switches the power to the LEDs.
8		8
9	## Usage	9	## Driver configuration
10		10
11	Most keyboards have backlighting enabled by default if they support it, but if it is not working for you, check that your `rules.mk` includes the following:	11	Most keyboards have backlighting enabled by default if they support it, but if it is not working for you, check that your `rules.mk` includes the following:
12		12
13	```make	13	```makefile
14	BACKLIGHT_ENABLE = yes	14	BACKLIGHT_ENABLE = software # Valid driver values are 'yes,software,no'
15	```	15	```
16		16
		17	See below for help on individual drivers.
		18
17	## Keycodes	19	## Keycodes
18	Once enabled the following keycodes below can be used to change the backlight level.	20	Once enabled the following keycodes below can be used to change the backlight level.
19		21
@@ -27,8 +29,54 @@ Once enabled the following keycodes below can be used to change the backlight le
27	\|`BL_DEC` \|Decrease the backlight level \|	29	\|`BL_DEC` \|Decrease the backlight level \|
28	\|`BL_BRTG`\|Toggle backlight breathing \|	30	\|`BL_BRTG`\|Toggle backlight breathing \|
29		31
		32	## Backlight Functions
		33
		34	\|Function \|Description \|
		35	\|----------\|-----------------------------------------------------------\|
		36	\|`backlight_toggle()` \|Turn the backlight on or off \|
		37	\|`backlight_enable()` \|Turn the backlight on \|
		38	\|`backlight_disable()` \|Turn the backlight off \|
		39	\|`backlight_step()` \|Cycle through backlight levels \|
		40	\|`backlight_increase()` \|Increase the backlight level \|
		41	\|`backlight_decrease()` \|Decrease the backlight level \|
		42	\|`backlight_level(x)` \|Sets the backlight level to specified level \|
		43	\|`get_backlight_level()` \|Return the current backlight level \|
		44	\|`is_backlight_enabled()`\|Return whether the backlight is currently on \|
		45
		46	### Backlight Breathing Functions
		47
		48	\|Function \|Description \|
		49	\|----------\|---------------------------------------------------\|
		50	\|`breathing_toggle()` \|Turn the backlight breathing on or off \|
		51	\|`breathing_enable()` \|Turns on backlight breathing \|
		52	\|`breathing_disable()` \|Turns off backlight breathing \|
		53
		54	## Common Driver Configuration
		55
		56	To change the behavior of the backlighting, `#define` these in your `config.h`:
		57
		58	\|Define \|Default \|Description \|
		59	\|---------------------\|-------------\|--------------------------------------------------------------------------------------\|
		60	\|`BACKLIGHT_LEVELS` \|`3` \|The number of brightness levels (maximum 31 excluding off) \|
		61	\|`BACKLIGHT_CAPS_LOCK`\|Not defined\|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED) \|
		62	\|`BACKLIGHT_BREATHING`\|Not defined\|Enable backlight breathing, if supported \|
		63	\|`BREATHING_PERIOD` \|`6` \|The length of one backlight "breath" in seconds \|
		64	\|`BACKLIGHT_ON_STATE` \|`0` \|The state of the backlight pin when the backlight is "on" - `1` for high, `0` for low \|
		65
		66	### Backlight On State
		67
		68	Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor on and light the LEDs, you must drive the backlight pin, connected to the gate or base, high.
		69	Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case, when the transistor is on, the pin is driven low instead.
		70
		71	This functionality is configured at the keyboard level with the `BACKLIGHT_ON_STATE` define.
		72
30	## AVR driver	73	## AVR driver
31		74
		75	On AVR boards, the default driver currently sniffs the configuration to pick the best scenario. To enable it, add this to your rules.mk:
		76	```makefile
		77	BACKLIGHT_ENABLE = yes
		78	```
		79
32	### Caveats	80	### Caveats
33		81
34	Hardware PWM is supported according to the following table:	82	Hardware PWM is supported according to the following table:
@@ -63,22 +111,10 @@ When both timers are in use for Audio, the backlight PWM will not use a hardware
63		111
64	To change the behavior of the backlighting, `#define` these in your `config.h`:	112	To change the behavior of the backlighting, `#define` these in your `config.h`:
65		113
66	\|Define \|Default \|Description \|	114	\|Define \|Default \|Description \|
67	\|---------------------\|-------------\|-------------------------------------------------------------------------------------------------------------\|	115	\|---------------------\|-------------\|--------------------------------------------------------------------------------------------------------------\|
68	\|`BACKLIGHT_PIN` \|`B7` \|The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this\|	116	\|`BACKLIGHT_PIN` \|`B7` \|The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this \|
69	\|`BACKLIGHT_PINS` \|Not defined\|experimental: see below for more information \|	117	\|`BACKLIGHT_PINS` \|Not defined\|experimental: see below for more information \|
70	\|`BACKLIGHT_LEVELS` \|`3` \|The number of brightness levels (maximum 31 excluding off) \|
71	\|`BACKLIGHT_CAPS_LOCK`\|Not defined\|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED) \|
72	\|`BACKLIGHT_BREATHING`\|Not defined\|Enable backlight breathing, if supported \|
73	\|`BREATHING_PERIOD` \|`6` \|The length of one backlight "breath" in seconds \|
74	\|`BACKLIGHT_ON_STATE` \|`0` \|The state of the backlight pin when the backlight is "on" - `1` for high, `0` for low \|
75
76	### Backlight On State
77
78	Most backlight circuits are driven by an N-channel MOSFET or NPN transistor. This means that to turn the transistor on and light the LEDs, you must drive the backlight pin, connected to the gate or base, high.
79	Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case, when the transistor is on, the pin is driven low instead.
80
81	This functionality is configured at the keyboard level with the `BACKLIGHT_ON_STATE` define.
82		118
83	### Multiple backlight pins	119	### Multiple backlight pins
84		120
@@ -103,7 +139,7 @@ In this way `OCRxx` essentially controls the duty cycle of the LEDs, and thus th
103	The breathing effect is achieved by registering an interrupt handler for `TIMER1_OVF_vect` that is called whenever the counter resets, roughly 244 times per second.	139	The breathing effect is achieved by registering an interrupt handler for `TIMER1_OVF_vect` that is called whenever the counter resets, roughly 244 times per second.
104	In this handler, the value of an incrementing counter is mapped onto a precomputed brightness curve. To turn off breathing, the interrupt handler is simply disabled, and the brightness reset to the level stored in EEPROM.	140	In this handler, the value of an incrementing counter is mapped onto a precomputed brightness curve. To turn off breathing, the interrupt handler is simply disabled, and the brightness reset to the level stored in EEPROM.
105		141
106	### Software PWM Implementation	142	### Timer Assisted PWM Implementation
107		143
108	When `BACKLIGHT_PIN` is not set to a hardware backlight pin, QMK will use a hardware timer configured to trigger software interrupts. This time will count up to `ICRx` (by default `0xFFFF`) before resetting to 0.	144	When `BACKLIGHT_PIN` is not set to a hardware backlight pin, QMK will use a hardware timer configured to trigger software interrupts. This time will count up to `ICRx` (by default `0xFFFF`) before resetting to 0.
109	When resetting to 0, the CPU will fire an OVF (overflow) interrupt that will turn the LEDs on, starting the duty cycle.	145	When resetting to 0, the CPU will fire an OVF (overflow) interrupt that will turn the LEDs on, starting the duty cycle.
@@ -114,9 +150,14 @@ The breathing effect is the same as in the hardware PWM implementation.
114		150
115	## ARM Driver	151	## ARM Driver
116		152
		153	While still in its early stages, ARM backlight support aims to eventually have feature parity with AVR. To enable it, add this to your rules.mk:
		154	```makefile
		155	BACKLIGHT_ENABLE = yes
		156	```
		157
117	### Caveats	158	### Caveats
118		159
119	Currently only hardware PWM is supported, and does not provide automatic configuration.	160	Currently only hardware PWM is supported, not timer assisted, and does not provide automatic configuration.
120		161
121	?> STMF072 support is being investigated.	162	?> STMF072 support is being investigated.
122		163
@@ -130,30 +171,32 @@ To change the behavior of the backlighting, `#define` these in your `config.h`:
130	\|`BACKLIGHT_PWM_DRIVER` \|`PWMD4` \|The PWM driver to use, see ST datasheets for pin to PWM timer mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|	171	\|`BACKLIGHT_PWM_DRIVER` \|`PWMD4` \|The PWM driver to use, see ST datasheets for pin to PWM timer mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|
131	\|`BACKLIGHT_PWM_CHANNEL` \|`3` \|The PWM channel to use, see ST datasheets for pin to PWM channel mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|	172	\|`BACKLIGHT_PWM_CHANNEL` \|`3` \|The PWM channel to use, see ST datasheets for pin to PWM channel mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|
132	\|`BACKLIGHT_PAL_MODE` \|`2` \|The pin alternative function to use, see ST datasheets for pin AF mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|	173	\|`BACKLIGHT_PAL_MODE` \|`2` \|The pin alternative function to use, see ST datasheets for pin AF mapping. Unless you are designing your own keyboard, you shouldn't need to change this\|
133	\|`BACKLIGHT_LEVELS` \|`3` \|The number of brightness levels (maximum 31 excluding off) \|
134	\|`BACKLIGHT_CAPS_LOCK` \|Not defined\|Enable Caps Lock indicator using backlight (for keyboards without dedicated LED) \|
135	\|`BACKLIGHT_BREATHING` \|Not defined\|Enable backlight breathing, if supported \|
136	\|`BREATHING_PERIOD` \|`6` \|The length of one backlight "breath" in seconds \|
137		174
138	## Backlight Functions	175	## Software PWM Driver
139		176
140	\|Function \|Description \|	177	Emulation of PWM while running other keyboard tasks, it offers maximum hardware compatibility without extra platform configuration. The tradeoff is the backlight might jitter when the keyboard is busy. To enable, add this to your rules.mk:
141	\|----------\|-----------------------------------------------------------\|	178	```makefile
142	\|`backlight_toggle()` \|Turn the backlight on or off \|	179	BACKLIGHT_ENABLE = software
143	\|`backlight_enable()` \|Turn the backlight on \|	180	```
144	\|`backlight_disable()` \|Turn the backlight off \|
145	\|`backlight_step()` \|Cycle through backlight levels \|
146	\|`backlight_increase()` \|Increase the backlight level \|
147	\|`backlight_decrease()` \|Decrease the backlight level \|
148	\|`backlight_level(x)` \|Sets the backlight level, from 0 to \|
149	\| \|`BACKLIGHT_LEVELS` \|
150	\|`get_backlight_level()` \|Return the current backlight level \|
151	\|`is_backlight_enabled()`\|Return whether the backlight is currently on \|
152		181
153	### Backlight Breathing Functions	182	### Software PWM Configuration
		183
		184	To change the behavior of the backlighting, `#define` these in your `config.h`:
		185
		186	\|Define \|Default \|Description \|
		187	\|-----------------\|-------------\|-------------------------------------------------------------------------------------------------------------\|
		188	\|`BACKLIGHT_PIN` \|`B7` \|The pin that controls the LEDs. Unless you are designing your own keyboard, you shouldn't need to change this\|
		189	\|`BACKLIGHT_PINS` \|Not defined\|experimental: see below for more information \|
154		190
155	\|Function \|Description \|	191	### Multiple backlight pins
156	\|----------\|----------------------------------------------------------\|	192
157	\|`breathing_toggle()` \|Turn the backlight breathing on or off \|	193	Most keyboards have only one backlight pin which control all backlight LEDs (especially if the backlight is connected to an hardware PWM pin).
158	\|`breathing_enable()` \|Turns on backlight breathing \|	194	In software PWM, it is possible to define multiple backlight pins. All those pins will be turned on and off at the same time during the PWM duty cycle.
159	\|`breathing_disable()` \|Turns off backlight breathing \|	195	This feature allows to set for instance the Caps Lock LED (or any other controllable LED) brightness at the same level as the other LEDs of the backlight. This is useful if you have mapped LCTRL in place of Caps Lock and you need the Caps Lock LED to be part of the backlight instead of being activated when Caps Lock is on.
		196
		197	To activate multiple backlight pins, you need to add something like this to your user `config.h`:
		198
		199	```c
		200	#undef BACKLIGHT_PIN
		201	#define BACKLIGHT_PINS { F5, B2 }
		202	```