Software adjustment of LCD monitor brightness in Raspberry Pi












4














This is my first post here. I'm at the beginning of the road called Raspberry Pi.



Is there any way of changing the gamma/contrast/brightness of monitor via Raspberry Pi?



My Samsung 960BF doesn't have any hardware adjustment, only a power button.



I tried using xbacklight and got error




"No outputs have backlight property".




gddccontrol also didn't work. Error:



I/O warning: failed to load external entity "/home/pi/.dccontrol/monitorlist"  
Document not parsed successfully
Probing for available monitors"


And nothing is happening.



I connected my monitor through DVI-HDMI cable. Maybe this is why it doesn't work?



I'm using Raspberry Pi B+ V1.2 with Raspbian.










share|improve this question





























    4














    This is my first post here. I'm at the beginning of the road called Raspberry Pi.



    Is there any way of changing the gamma/contrast/brightness of monitor via Raspberry Pi?



    My Samsung 960BF doesn't have any hardware adjustment, only a power button.



    I tried using xbacklight and got error




    "No outputs have backlight property".




    gddccontrol also didn't work. Error:



    I/O warning: failed to load external entity "/home/pi/.dccontrol/monitorlist"  
    Document not parsed successfully
    Probing for available monitors"


    And nothing is happening.



    I connected my monitor through DVI-HDMI cable. Maybe this is why it doesn't work?



    I'm using Raspberry Pi B+ V1.2 with Raspbian.










    share|improve this question



























      4












      4








      4


      1





      This is my first post here. I'm at the beginning of the road called Raspberry Pi.



      Is there any way of changing the gamma/contrast/brightness of monitor via Raspberry Pi?



      My Samsung 960BF doesn't have any hardware adjustment, only a power button.



      I tried using xbacklight and got error




      "No outputs have backlight property".




      gddccontrol also didn't work. Error:



      I/O warning: failed to load external entity "/home/pi/.dccontrol/monitorlist"  
      Document not parsed successfully
      Probing for available monitors"


      And nothing is happening.



      I connected my monitor through DVI-HDMI cable. Maybe this is why it doesn't work?



      I'm using Raspberry Pi B+ V1.2 with Raspbian.










      share|improve this question















      This is my first post here. I'm at the beginning of the road called Raspberry Pi.



      Is there any way of changing the gamma/contrast/brightness of monitor via Raspberry Pi?



      My Samsung 960BF doesn't have any hardware adjustment, only a power button.



      I tried using xbacklight and got error




      "No outputs have backlight property".




      gddccontrol also didn't work. Error:



      I/O warning: failed to load external entity "/home/pi/.dccontrol/monitorlist"  
      Document not parsed successfully
      Probing for available monitors"


      And nothing is happening.



      I connected my monitor through DVI-HDMI cable. Maybe this is why it doesn't work?



      I'm using Raspberry Pi B+ V1.2 with Raspbian.







      debian display raspberry-pi raspbian






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Jul 9 '15 at 20:15

























      asked Jul 8 '15 at 11:28









      tarzanno

      77415




      77415






















          1 Answer
          1






          active

          oldest

          votes


















          0














          One tool I have used successfully (not on a pi though), is xcalib from the package of the same name. You can use it to change the gamma, eg:



          xcalib -gc 1.1 -a


          You can repeat this. To cancel use



          xcalib -clear


          Another useful option is making the whole screen reverse-video:



           xcalib -invert -a


          It is intended to work with icc profiles, but I have only used the above commands.






          share|improve this answer





















          • Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
            – tarzanno
            Jul 8 '15 at 13:44












          • You would need -b 99 -a but I wouldnt do that, the screen will be all white.
            – meuh
            Jul 11 '15 at 4:34










          • Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
            – tarzanno
            Jul 11 '15 at 11:47










          • Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
            – meuh
            Jul 11 '15 at 12:12












          • Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
            – tarzanno
            Jul 11 '15 at 12:31











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          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          0














          One tool I have used successfully (not on a pi though), is xcalib from the package of the same name. You can use it to change the gamma, eg:



          xcalib -gc 1.1 -a


          You can repeat this. To cancel use



          xcalib -clear


          Another useful option is making the whole screen reverse-video:



           xcalib -invert -a


          It is intended to work with icc profiles, but I have only used the above commands.






          share|improve this answer





















          • Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
            – tarzanno
            Jul 8 '15 at 13:44












          • You would need -b 99 -a but I wouldnt do that, the screen will be all white.
            – meuh
            Jul 11 '15 at 4:34










          • Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
            – tarzanno
            Jul 11 '15 at 11:47










          • Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
            – meuh
            Jul 11 '15 at 12:12












          • Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
            – tarzanno
            Jul 11 '15 at 12:31
















          0














          One tool I have used successfully (not on a pi though), is xcalib from the package of the same name. You can use it to change the gamma, eg:



          xcalib -gc 1.1 -a


          You can repeat this. To cancel use



          xcalib -clear


          Another useful option is making the whole screen reverse-video:



           xcalib -invert -a


          It is intended to work with icc profiles, but I have only used the above commands.






          share|improve this answer





















          • Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
            – tarzanno
            Jul 8 '15 at 13:44












          • You would need -b 99 -a but I wouldnt do that, the screen will be all white.
            – meuh
            Jul 11 '15 at 4:34










          • Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
            – tarzanno
            Jul 11 '15 at 11:47










          • Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
            – meuh
            Jul 11 '15 at 12:12












          • Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
            – tarzanno
            Jul 11 '15 at 12:31














          0












          0








          0






          One tool I have used successfully (not on a pi though), is xcalib from the package of the same name. You can use it to change the gamma, eg:



          xcalib -gc 1.1 -a


          You can repeat this. To cancel use



          xcalib -clear


          Another useful option is making the whole screen reverse-video:



           xcalib -invert -a


          It is intended to work with icc profiles, but I have only used the above commands.






          share|improve this answer












          One tool I have used successfully (not on a pi though), is xcalib from the package of the same name. You can use it to change the gamma, eg:



          xcalib -gc 1.1 -a


          You can repeat this. To cancel use



          xcalib -clear


          Another useful option is making the whole screen reverse-video:



           xcalib -invert -a


          It is intended to work with icc profiles, but I have only used the above commands.







          share|improve this answer












          share|improve this answer



          share|improve this answer










          answered Jul 8 '15 at 13:28









          meuh

          3,4101921




          3,4101921












          • Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
            – tarzanno
            Jul 8 '15 at 13:44












          • You would need -b 99 -a but I wouldnt do that, the screen will be all white.
            – meuh
            Jul 11 '15 at 4:34










          • Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
            – tarzanno
            Jul 11 '15 at 11:47










          • Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
            – meuh
            Jul 11 '15 at 12:12












          • Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
            – tarzanno
            Jul 11 '15 at 12:31


















          • Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
            – tarzanno
            Jul 8 '15 at 13:44












          • You would need -b 99 -a but I wouldnt do that, the screen will be all white.
            – meuh
            Jul 11 '15 at 4:34










          • Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
            – tarzanno
            Jul 11 '15 at 11:47










          • Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
            – meuh
            Jul 11 '15 at 12:12












          • Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
            – tarzanno
            Jul 11 '15 at 12:31
















          Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
          – tarzanno
          Jul 8 '15 at 13:44






          Thanks for reply. I tried this, but nothing happens, end after executing command: xcalib -b 99 there is an error: "Warning: Unable to read file ' ' "
          – tarzanno
          Jul 8 '15 at 13:44














          You would need -b 99 -a but I wouldnt do that, the screen will be all white.
          – meuh
          Jul 11 '15 at 4:34




          You would need -b 99 -a but I wouldnt do that, the screen will be all white.
          – meuh
          Jul 11 '15 at 4:34












          Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
          – tarzanno
          Jul 11 '15 at 11:47




          Unfortunately, it doesn't work either. I tried 'xcalib -b 99 -a', 'sudo xcalib -b 99 -a' , and 'xcalib -b 10 -a' to make sure my monitor is not set to max brightness already. There is no error and nothing is happening. I'm afraid that I will need to learn i2c and control the monitor by that...
          – tarzanno
          Jul 11 '15 at 11:47












          Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
          – meuh
          Jul 11 '15 at 12:12






          Perhaps your cable is not passing through the i2c data line. Look in your /var/log/Xorg.0.log or similar log file to see if the display's eeprom was found (look for EDID).
          – meuh
          Jul 11 '15 at 12:12














          Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
          – tarzanno
          Jul 11 '15 at 12:31




          Nothing like that exists in this file. There is only a line telling that Rpi is using default monitor and : "no device specified for default monitor section". Must I buy a new HDMI-DVI cable, or there is another way?
          – tarzanno
          Jul 11 '15 at 12:31


















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