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| author | fauxpark <fauxpark@gmail.com> | 2019-06-20 15:33:39 +1000 |
|---|---|---|
| committer | Drashna Jaelre <drashna@live.com> | 2019-06-19 22:33:39 -0700 |
| commit | 317b8095647e208a7ac1ecf6b110051ca46553a8 (patch) | |
| tree | 724a2dc9d0b5071999f25400c453ca061e1c0827 /docs/feature_backlight.md | |
| parent | 67e0c951afee99ac1e1e96354655296457f57b78 (diff) | |
Fix breathing always on for soft PWM (#5983)
* Fix breathing always on for soft PWM
* Remove reference to hardware PWM pins in BACKLIGHT_BREATHING description
Now, breathing will only be unsupported when Timers 1 and 3 are both used by Audio
* Document BACKLIGHT_ON_STATE and its purpose
Diffstat (limited to 'docs/feature_backlight.md')
| -rw-r--r-- | docs/feature_backlight.md | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/docs/feature_backlight.md b/docs/feature_backlight.md index 5a21a67901..b06db89e4d 100644 --- a/docs/feature_backlight.md +++ b/docs/feature_backlight.md @@ -64,11 +64,17 @@ To change the behaviour 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| +|`BACKLIGHT_PINS` |*Not defined*|experimental: see below for more information | |`BACKLIGHT_LEVELS` |`3` |The number of brightness levels (maximum 15 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 | +|`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, *low*. +Sometimes, however, a P-channel MOSFET, or a PNP transistor is used. In this case you must `#define BACKLIGHT_ON_STATE 1`, so that when the transistor is on, the pin is driven *high* instead. ## Multiple backlight pins |