Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I was wondering if there's a way to tweak the steps that the luminosity of my lcd do when adjusting it from keyboard.

It seems that they are just +/-30% of total, and that's pretty annoying, because sometimes it would be useful to have more control on it. As an example now: 0 is too low, but 30% is too high. I can reach 10% by letting it 100% and then down 30 by 30 until 10, but it's still too low.

I'd like to have a more fine control on it, like the 18 steps of the sound.

I'm on an Acer Extensa 5620, here's my lshw:

$ sudo lshw -short -sanitize
H/W path               Device      Class       Description
==========================================================
                                   system      Notebook
/0                                 bus         Columbia
/0/0                               memory      105KiB BIOS
/0/4                               processor   Intel(R) Core(TM)2 Duo CPU     T5550  @ 1.83GHz
/0/4/5                             memory      64KiB L1 cache
/0/4/6                             memory      2MiB L2 cache
/0/4/1.1                           processor   Logical CPU
/0/4/1.2                           processor   Logical CPU
/0/10                              memory      3GiB System Memory
/0/10/0                            memory      1GiB SODIMM DDR2 Synchronous 667 MHz (1,5 ns)
/0/10/1                            memory      2GiB SODIMM DDR2 Synchronous 667 MHz (1,5 ns)
/0/1                               processor   
/0/1/1.1                           processor   Logical CPU
/0/1/1.2                           processor   Logical CPU
/0/100                             bridge      Mobile PM965/GM965/GL960 Memory Controller Hub
/0/100/2                           display     Mobile GM965/GL960 Integrated Graphics Controller (primary)
/0/100/2.1                         display     Mobile GM965/GL960 Integrated Graphics Controller (secondary)
/0/100/1a                          bus         82801H (ICH8 Family) USB UHCI Controller #4
/0/100/1a.1                        bus         82801H (ICH8 Family) USB UHCI Controller #5
/0/100/1a.7                        bus         82801H (ICH8 Family) USB2 EHCI Controller #2
/0/100/1b                          multimedia  82801H (ICH8 Family) HD Audio Controller
/0/100/1c                          bridge      82801H (ICH8 Family) PCI Express Port 1
/0/100/1c/0            eth0        network     NetLink BCM5787M Gigabit Ethernet PCI Express
/0/100/1c.1                        bridge      82801H (ICH8 Family) PCI Express Port 2
/0/100/1c.1/0          wlan0       network     PRO/Wireless 3945ABG [Golan] Network Connection
/0/100/1c.2                        bridge      82801H (ICH8 Family) PCI Express Port 3
/0/100/1d                          bus         82801H (ICH8 Family) USB UHCI Controller #1
/0/100/1d.1                        bus         82801H (ICH8 Family) USB UHCI Controller #2
/0/100/1d.2                        bus         82801H (ICH8 Family) USB UHCI Controller #3
/0/100/1d.7                        bus         82801H (ICH8 Family) USB2 EHCI Controller #1
/0/100/1e                          bridge      82801 Mobile PCI Bridge
/0/100/1e/6                        bridge      PCIxx12 Cardbus Controller
/0/100/1e/6.1                      bus         PCIxx12 OHCI Compliant IEEE 1394 Host Controller
/0/100/1e/6.2                      storage     5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)
/0/100/1e/6.3                      generic     PCIxx12 SDA Standard Compliant SD Host Controller
/0/100/1f                          bridge      82801HEM (ICH8M) LPC Interface Controller
/0/100/1f.1            scsi0       storage     82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller
/0/100/1f.1/0.0.0      /dev/cdrom  disk        DVDRAM GSA-T40N
/0/100/1f.2            scsi2       storage     82801HBM/HEM (ICH8M/ICH8M-E) SATA IDE Controller
/0/100/1f.2/0.0.0      /dev/sda    disk        250GB Hitachi HTS54252
/0/100/1f.2/0.0.0/1    /dev/sda1   volume      26GiB Windows NTFS volume
/0/100/1f.2/0.0.0/2    /dev/sda2   volume      17GiB Extended partition
/0/100/1f.2/0.0.0/2/5  /dev/sda5   volume      3200MiB Linux swap / Solaris partition
/0/100/1f.2/0.0.0/2/6  /dev/sda6   volume      14GiB Linux filesystem partition
/0/100/1f.2/0.0.0/3    /dev/sda3   volume      189GiB EXT3 volume
/0/100/1f.3                        bus         82801H (ICH8 Family) SMBus Controller
/0/2                   scsi12      storage     
/0/2/0.0.0             /dev/sdb    disk        SCSI Disk

Any tip?

Many thanks in advance!

share|improve this question
add comment

1 Answer 1

up vote 0 down vote accepted

Probably ...

Directly

echo '100' > /sys/class/backlight/psb-bl/brightness
echo `'50' > /sys/class/backlight/psb-bl/brightness

You simply have to adjust the path, /sys/class/backlight/your_device/brightness

xbacklight

Alternately you can try installing xbacklight

sudo apt-get install xbacklight

xbacklight -inc 10
xbacklight -dec 10
xbacklight -set 60

See man xbacklight

share|improve this answer
    
I've got 2 devices listed in /sys/class/backlight/: acpi_video0 and intel_backlight. The first is the one with changing luminosity when using keyboard, while the other one's is always 0. The range is 0-9, moving 4 by 4 from keyboard. Using the first codes (with sudo) says me a no No permission error. I'll try xbacklight now. –  dadexix86 Jan 17 '12 at 23:28
    
Ok, xbacklight is working, but just with a 20% increment, with some strange steps too. Starting from 0 and using several times xbacklight -inc 20 && xbacklight -get I get 11.111111, 22.222222, 33.333333, 44.444444, 55.555556, 66.666667, 77.777778, 88.888889, 100.000000. Anyway, many thanks :) I'll try add it to some keyboard combinations. –  dadexix86 Jan 17 '12 at 23:46
    
You might be looking at a limitation of your hardware, I am not sure. Try sudo echo '40' > /sys/class/backlight/acpi_video0 –  bodhi.zazen Jan 17 '12 at 23:50
    
sudo echo '40' > /sys/class/backlight/acpi_video0 bash: /sys/class/backlight/acpi_video0: È una directory (It is a directory) and sudo echo '40' > /sys/class/backlight/acpi_video0/brightness bash: /sys/class/backlight/acpi_video0/brightness: Permesso negato (No Permission) –  dadexix86 Jan 17 '12 at 23:59
    
@dadexix86, I have the same and acpi_video0 seems like a generalized version of intel_backlight, as echo'ng 0 to intel_backlight/brightness totally blacks the screen, whereas doing so to acpi_video0/brightness only dims to a certain level. –  Dykam May 13 '12 at 23:58
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.