Thread: [Request] Status-menu plugin to enable/disable the hardware keyboard's backlight
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joerg_rw is offline joerg_rw
2012-04-16 , 12:14
Posts: 2,222 | Thanked: 12,651 times | Joined on Mar 2010 @ SOL 3
#2
the kbd backlight is controlled via mce process and lp5523 kernel driver in /sys/class/leds/lp5523:kb?/* and engine3.
Possible hooks are:
/etc/mce/mce.ini ([KeyPad] BacklightTimeout=30) problem: mce needs a restart to read in new values from mce.ini
/sys/class/leds/lp5523:kb?/led_current
/sys/class/leds/lp5523:kb?/brightness
/sys/class/i2c-adapter/i2c-2/2-0032/engine3_mode

see http://wiki.maemo.org/N900_Hardware_LED and http://wiki.maemo.org/LED_patterns#Low_Level for details.

Code:
for L in /sys/class/leds/lp5523:kb?; do echo 0 >$L/led_current; done
is accomplishing a shutdown of backlight. Alas mce will restore the default value 50 to all led_current nodes when kbd backlight gets re-enabled. This also might happen on random moments, I haven't done extensive tests.
Beware! Values >50 for led_current may instantly kill your LEDs!

Anyway I hope it helps you with some suggestions where to start.

/jOERG

[edit] ps.: please notice your kbd backlight will get turned off when ambient light is bright enough
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Last edited by joerg_rw; 2012-04-16 at 13:01.
 

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