Display problem while mouse moving

  • Hi


    We have a problem with a new 10,4 Inch Display. F&S has written a new driver for this Display and NetDCU8. Now, it's working good with PicoCOM4, but when i plug this Display on the NetDCU8 we have a flickering while booting up and after the boot we also have flickering when we move the mouse. If we don't do anything, the Display is looking good.
    Has somebody any idea how to solve this problem?


    Thanks.
    Best regards!

  • What is the display resolution? Due to limited internal bus bandwidth only resolution up to 640x480 is supported with full refresh rate.
    Try lowering the pixel clock to reduce the refresh rate and see if this helps.

    F&S Elektronik Systeme GmbH
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  • Thanks for your awnser.


    The resolution is 640x480. The datasheet of the display is saying minimul clock frequency is 21MHz. If i lower to this (lcdclk dword 21) the main flickering is away, but the screens is repeating in two areas some columns, it looks splitted, and in this two areas its flickering all the time. The picture is then widther than the screen.

  • Did you measure the clock? The clock is not freely setable, it is the divided bus clock.
    So only 20, 25, and 33 MHz are usable for VGA resolution. Try different LCD clock values until one of these is set, e.g. try 24, 25, 26, and 27 to get the 25MHz.

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    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • I tryed any single value between 10 and 40:


    lcdclk / measured clockfrequency
    10...11 / 10.2MHz
    12...14 / 12.75MHz
    15...21 / 17MHz
    22...38 / 25.5MHz
    39...40 / 51MHz


    And the Display looks bad on any value I tryed:


    at 25MHz look at my first post
    at 17Mhz look at my second post
    at 12, 10, 51MHz it's undiscriptable bad

  • 25Mhz should be ok for the display.
    Please look at the Clock and Sync signals and check if they have the right polarity.

    F&S Elektronik Systeme GmbH
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    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • OK, if they don't have the right polarity, can i fix that with the software driver? Witch parameter is for the polarity of the clock and the sync? And what did u mean with sync, is that the data enable signal?

  • The 'config' value of the display settings set the polarities.
    Please see the display settings document for the NetDCU8 from our download area for details.
    Did you connect both HSync/VSync and DE to the display? On many displays this doesn't work properly.

    F&S Elektronik Systeme GmbH
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    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • "Data enable signal" from Display is connected to "M" (NetDCU8: J3 / Pin 21),
    "Dot clock" from Display is connected to "CLP" (NetDCU8: J3 / Pin 19),
    I don't have any HSync/VSync Signals on the Display.
    Changeing clock polarity doesn't make a difference, also changeing the sync, what doesn't surprise when i didn't connect this signals.
    Is there a possible way to change data enable polarity? I tried with parameter "MSignal" in display driver (0, 1 and 2) but also make no difference.

  • Please check the registry settings for the display.
    I have attached a document for calulating the values from the datat sheet

    Files

    F&S Elektronik Systeme GmbH
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    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • Thank you.
    I have checked the registry settings and i get the same values like F&S, who has writen this driver specialy for the NetDCU8 on our request.
    I'm wondering why is this driver running on a PicoCOM4 and not on NetDCU8 with the same signal connections.

  • Hello,
    just an assumption.
    Did you connect M-Signal and HSync VSync and does your lcd is able to handle this?
    Mayby msignal=DWORD:0 does not work on NetDCU8 but on PicoCOM4?

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • I don't have HSync/VSync Signals on that display. I have only M-Signal connected.


    Display driver settings:
    reg set value name string "DATAVISION DTFS104F0VLX"
    reg set value EFW dword 80
    reg set value BFW dword 80
    reg set value LPP dword 480
    reg set value msignal dword 2
    reg set value rows dword 480
    reg set value width dword 211
    reg set value height dword 158
    reg set value contrastenable dword 0
    reg set value contrastvalue dword 0
    reg set value type dword 6
    reg set value config dword 0x00700000
    reg set value columns dword 640
    reg set value HSW dword 35
    reg set value bpp dword 16
    reg set value PPL dword 640
    reg set value lcdclk dword 25
    reg set value VSW dword 2
    reg set value BLW dword 5
    reg set value ELW dword 5
    reg set value EnableCursor dword 1


    With all this driver settings the Display works on a PicoCOM4 but not on a NetDCU8. I don't know if msignal=DWORD:0 does work on PicoCOM4. I didn't try that because msignal=DWORD:2 is working well on PicoCOM4.

  • I had a look at the datasheet. They confused horizontal and vertical timing symbols.
    Try:
    reg set value HSW dword 35
    reg set value BLW dword 60
    reg set value ELW dword 60
    reg set value VSW dword 2
    reg set value EFW dword 20
    reg set value BFW dword 20

    F&S Elektronik Systeme GmbH
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  • After setting the new values you have to call "reg save" and restart the board. Otherwise the new settings will not take effect.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • I have tried that:


    reg open \drivers\display\samsung
    reg create key mode101
    reg set value name string "DATAVISION DTFS104F0VLX"
    reg set value EFW dword 20
    reg set value BFW dword 20
    reg set value LPP dword 480
    reg set value msignal dword 2
    reg set value rows dword 480
    reg set value width dword 211
    reg set value height dword 158
    reg set value contrastenable dword 0
    reg set value contrastvalue dword 0
    reg set value type dword 6
    reg set value config dword 0x00700000
    reg set value columns dword 640
    reg set value HSW dword 35
    reg set value bpp dword 16
    reg set value PPL dword 640
    reg set value lcdclk dword 25
    reg set value VSW dword 2
    reg set value BLW dword 60
    reg set value ELW dword 60
    reg set value EnableCursor dword 1
    display mode set 101
    reg save
    reboot


    mode101 was not created befor i send this. Is this looking correct for you?

  • This seems to be right.


    Probably we are thinking in the wrong direction all the time. How long is your cable to the display? Do you use the same cable for PicoCOM4 and NetDCU8? Or is the PicoCOM4 one shorter? 25 MHz is already quite prone to disturbances. Do you have flickering if you move the cable with your hand?


    Keep the cable as short as possible, e.g. 5cm. Maybe you can toggle the Pixel clock polarity (in entry config) to compensate for a too long cable.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • The cable was about 30cm long. I use the same cable for NetDCU8 and PicoCOM4, we have the same plug on our PicoCOM4 adaption like J3 on NetDCU8 (pincompatible). I have no flickering when i move the cable. I have also tried some cable ferrit without success.
    Now, i have shorten the cable to 10cm (5cm is not doable) again without success. I have also tried to toggle the clock polarity, again.

  • So let me summarize.


    You use the same settings on PicoCOM4 and NetDCU8? The final one with the new timing values?
    When measuring, you get the same pixel clock on both boards?
    When measuring, you get the same DE behaviour (active high)?


    Nonetheless the display is working OK on PicoCOM4 and it shows distortions when moving the mouse on NetDCU8?


    Inverting the pixel clock polarity does not help?
    A shorter display cable does not help?


    Well, then I'm out of ideas.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.