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V2 from a linux PC (not BB)

SA13071
Prodigy 220 points

I have a DLP Pico projector v2 and want to drive it from a 2nd graphics card in my linux box.  I have the xorg.conf setup to provide a 2nd xserver at 640*480 which works just fine on a 2nd monitor but produces zilch on the pico projector.

 

I suspect the modlines in the xorg.conf are not correct but I don't know what to set them to.

 

Has anyone had success using the V2 from a PC? under linux? dual head? any hints or a working xorg.conf gratefully received!

  • 0
    Prodigy 220 points

    The logs from the xserver contain the following:

    (WW) NVIDIA(GPU-0): The EDID read for display device CRT-1 is invalid:

    (WW) NVIDIA(GPU-0): unrecognized EDID Header.

    Which suggests there is something wrong with the EDID of the DLP Pico project V2

  • 0 in reply to SA13071
    Prodigy 85 points

    Got it working here is how:

     

    The EDID in my v2 projector is not recognised as valid by the video card (nvidia).  Consequently the card borks and won't driver the SLM.

    To get around this problem I hacked the xorg.conf:

    (1) I constructed a modeline for the SLM using gtf in the Modes section of the xorg.conf and deleted all the other options:

      Modeline "640x480"  23.86  640 656 720 800  480 481 484 497  -HSync +Vsync

    In the Screen section I used:

      SubSection "Display"
        Depth      24
        Modes      "640x480"
      EndSubSection
    to select this mode.

    (2) I instructed the video card / drvier to ignore the EDID it found by adding this line to the drvier section of the xorg.conf:

      Option        "UseEDID"       "False"

    (3) I instructed the video card / driver to output to the DVI-D regardless of what it found (in my case no monitor attached) by adding the following line to the driver section of the xorg.conf:

      Option        "ConnectedMonitor" "DFP"

    I rebooted X and it worked.

    I was using a 2nd nvidia PCI card (while keeping the primary for my monitor) YMMV

    You may also be interested that KDE tries to manage both screens (monitor + SLM) which is a pain in the *** and to stop it you insert the following line to the [X11] section of the kcmdisplayrc config file for KDE:

    disableMultihead=true

    Again YMMV

     

    SA

     

     

     

  • 0 in reply to t emp
    TI__Intellectual 2265 points

    SA,

    Thank you for sharing your findings.

    The Pico V2 input is default to 640x480 (VGA) at 60Hz. The EDID will be looking for that setting. Many times, if the the input is set to 50Hz or other resolutions, the Pico does not respond.

     

     

  • 0 in reply to WYA
    Prodigy 85 points

    I'm not sure what you mean by "the EDID will be looking for that setting", AFAIK the EDID is just an eprom that tells the graphics card what monitor is connected and what modes it supports.

    In this case the graphics card is reporting the EDID the pico projector reports values are invalid and unless I have a special case this means that the pico projector won't just plug and play for pc graphics cards. 

    The solution I posted here forces this card to ignore the EDID and output to 640*480 resolution at 60Hz.

  • 0 in reply to t emp
    TI__Intellectual 2265 points

    SA

    The source device (i.e. PC) checks for the presence of an EDID prom through the DVI interface and uses the information inside the EEPROM to output the proper video format. The EDID PROM read over standard HDMI I/F is VGA 640 x 480 only. This is the default setting.

  • 0 in reply to WYA
    Prodigy 85 points

    My video card reports the EDID as invalid (possibly corrupt) hence the problem...

  • 0 in reply to t emp
    Prodigy 85 points

    Form the PC the Pico projector says the EDID is invalid

    Form the BB

    decode-edid

    gives me this:

    EDID EEPROM not found.  Please make sure that the eeprom module is loaded.

    but I'm not sure what the problem is here...

     

     

    I'd much prefer to use the pico from the PC but don't know how to access the i2c this way (I was using bus3-i2c on the BB but what on the linux PC?). Without the I2C commands I can't set the pico to the mode I need...