Results 1 to 9 of 9

Thread: Touch screen interference

  1. #1
    Newbie kensbey's Avatar
    Join Date
    Jul 2008
    Location
    brisbane australia
    Posts
    42

    Touch screen interference

    hey all,
    i've just put my laptop and touch screen in, but i am getting all sorts of interference on the monitor. the picture comes through and the touch screen still functions.. but there are lines moving up the screen etc.. but only when the laptop is running of the dc power supply. when i unplug the laptop from the cigarette lighter and have it on batteries the screen works fine.... also i tried using an external battery to run them and found that if i power both the laptop and the screen of the external battery theres interference, but if i power 1 off the car and one off the battery it works fine.... any ideas?

  2. #2
    Newbie
    Join Date
    Dec 2006
    Posts
    12
    I have the same problem. Did you figure it out?

  3. #3
    Newbie kensbey's Avatar
    Join Date
    Jul 2008
    Location
    brisbane australia
    Posts
    42
    yeh i fixed it... the problem was the dc power supply... i switched over to using an inverter and the ac power supply that came with the laptop and it all works good now

  4. #4
    Newbie
    Join Date
    Dec 2007
    Location
    Walsall
    Posts
    11
    Bringing an old thread back to life............

    Wouldn't the inverter draw more power/current than the DC/DC supply? Thus putting more strain on the engine/alternator/car battery?

  5. #5
    Fusion Brain Creator 2k1Toaster's Avatar
    Join Date
    Mar 2006
    Location
    Colorado, but Canadian!
    Posts
    10,049
    Quote Originally Posted by A6_TWK View Post
    Bringing an old thread back to life............

    Wouldn't the inverter draw more power/current than the DC/DC supply? Thus putting more strain on the engine/alternator/car battery?
    yes but that isnt the issue. Audio interference and a bunch of other nasty things are introduced with an inverter. You just need to properly wire things with good sized cables and space the cables correctly and interference wont be an issue.
    Fusion Brain Version 6 Released!
    1.9in x 2.9in -- 47mm x 73mm
    30 Digital Outputs -- Directly drive a relay
    15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
    Buy now in the MP3Car.com Store

  6. #6
    Newbie
    Join Date
    Dec 2007
    Location
    Walsall
    Posts
    11
    Interesting.

    I've got the "Lines" on my Lilliput at the moment, and the too go away when i use the AC/DC adapter off the house supply. I'm against using an iverter basically because I see it as a useless increase in voltage just to come back down to 12V again. I've been advised to bypass the adapter and earth the -ve terminal off the adapter pin to the cars ground as opposed to going back through the adapter. Would this work do you think?

  7. #7
    Admin. Linux loser.
    Auto Apps:loading...
    Bugbyte's Avatar
    Join Date
    Sep 2004
    Location
    Corning, NY
    Posts
    7,359
    Blog Entries
    2
    It *might* work, but the adaptor is already grounded to something and if you are using, say, the cigarette lighter for the power, then it is already grounded to the car's ground.

    One solution that can sometimes help is to run the screen off of the DC-DC power supply for the computer. It regulates the power and that may be the cause of the wavy lines.

    Also, I've heard that poor quality cables can be part of the issue. If you are using an extension to the Lilli cable, try a different one.
    Quote Originally Posted by ghettocruzer View Post
    I was gung ho on building a PC [until] just recently. However, between my new phone having internet and GPS and all...and this kit...Im starting to have trouble justfiying it haha.
    Want to:
    -Find out about the new iBug iPad install?
    -Find out about carPC's in just 5 minutes? View the Car PC 101 video

  8. #8
    Newbie kensbey's Avatar
    Join Date
    Jul 2008
    Location
    brisbane australia
    Posts
    42

    update

    hey guys,
    if you look at my project log, you can see that i got rid of the laptop, and replaced it with a proper pc. i came to this conclusion: while a laptop is good because its small and designed to be power efficient, you are always going to have issues with sound and picture interference in a car environment because all the components are integrated and so close together. with the new pc setup, running of a m4-atx, the interference came back a little, but no where near as bad as before, not really noticable... i have come to the conclusion that its mainly due to the tiny size of the ground cable that comes out of the touch screen. i plan to dissasemble my screen in the near future and improve all the grounding, hopefully this will remove it completely. i imagine the inveter worked as a fix as it didnt allow the screen to ground back through the pc.
    _-_-_-_-_-_-_-_-_
    Holden FTW!
    Carpc Mk 1
    Carpc Mk 2 (in Progress)

  9. #9
    Newbie
    Join Date
    Sep 2005
    Location
    Auckland, NZ
    Posts
    18

    Lightbulb

    I was having the same issue. Noise in the screen when laptop power plugged in and would go away completely if laptop was running on batteries. I tried 3 different laptop power supplies, noise filters etc but to no avail.

    Then I tried grounding the laptop's chassis. Voila!!! perfect screen with no noise!!!

    To ground the laptop I connected a thin ground wire to the metal surround of the parallel port. Even connecting it to the screw terminals of the vga port worked for me.

Similar Threads

  1. In-dash touch screen vs touch screen overlay
    By vxcarpc in forum LCD/Display
    Replies: 7
    Last Post: 09-22-2008, 11:52 PM
  2. Lilliput 8" touch screen backwards - FC4
    By DJBigShow in forum Linux
    Replies: 9
    Last Post: 08-04-2006, 03:43 PM
  3. Lilliput touch screen Help..please
    By avn128 in forum LCD/Display
    Replies: 2
    Last Post: 08-03-2006, 05:20 PM
  4. Need touch screen advice
    By sciff5 in forum LCD/Display
    Replies: 0
    Last Post: 05-29-2005, 10:58 PM
  5. task switching? touch screen only
    By chuckctv in forum Software & Software Development
    Replies: 5
    Last Post: 09-04-2004, 10:50 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •