LEDs and backlight

Status LEDs

Meaning of the LEDs from left to right according to gfrancisdev.

Left LED group

• SD card 1
• SD card 2
• Wifi
• Bluetooth

Right LED group

• Empty (with solder pad for hardware hackers who want to use an additional LED)
• Empty (-"-)
• Charging
• Power

Backlight

Brightness

The screen backlight power is controllable via a number of mechanisms:

• The 'sun' icon next to volume on the task bar - click it and drag the slider that appears to modify backlight power interactively
• The LCD-Settings app under Pandora menu->Settings - choose Change LCD brightness from the menu. This allows you to see the power value to be set, but doesn't change until you accept the setting and close the app
• Using the FN+u and FN+i keyboard shortcuts. This gives you quick access to screen brightness, but doesn't give you fine-grained control.

Note: For the top two methods, you can use the d-pad to change the power step by step. Up and right increase the power by 1 unit, and down or left decrease it similarly.

Power Saving

The backlight can be configured to dim to display after a period of inactivity. To set this option go to Pandora menu->Settings->LCD-Settings and choose 'Enable/disable screen blanking'.

By default this settings is disabled, since the Pandora disables the screen when the lid is closed, so unless you're in the habit of leaving your Pandora with the lid open for extended periods, this saves power and extends the lifetime of your LCD backlight by itself. Note that the lid closed settings are also configurable under Menu->Settings->Lid-Close-Settings.

Controlling LEDs and backlight programmatically

Available through LED and brightness classes:

/sys/class/leds/*
/sys/class/backlight/*

LED brightness and trigger and backlight brightness can be controlled through those files. Power and charger LEDs have variable brightness control, others are on/off only.

Note: SD card LEDs use SD cart power supplies, so those must be enabled for those LEDs to work (they are enabled when cards are inserted).

backlight power saving

Controlled by X server through omapfb_drv.so, ca be disabled by running

xset s off

config

Kept in /etc/default/leds (LEDs) and /etc/pandora/conf/brightness.state (backlight).

Note: driver allows lower brightness than you can set using keyboard controls, because some units start to flicker on lowest brightness. This can be changed in /usr/pandora/scripts/op_bright.sh .

Keyboard controls

Backlight controls, power switch and pandora button are handled by pndevmapperd which calls appropriate scripts as needed. The scripts reside in /usr/pandora/scripts/ . There is a op_test_inputs program included designed to test inputs.

config

/etc/pandora/conf/eventmap