Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: LCD Problems

  1. #1
    Low Bitrate
    Join Date
    Apr 2002
    Location
    Lafayette, LA
    Posts
    79

    LCD Problems

    I'm having a major problem with my LCD. I'm using a HD44780 4x20 LCD (Inversed, Red). Anyway, I am using LCDprint to display a boot message and WinLCD 1.01 for Winamp display.

    It all worked fine untill I put it in my car. Just now I went out and powered it up. At first I got no display. The blocks of text did change when LCDprint loaded, but there was no text. Then, after restarting and finding what I thought was a short from the DATA 1 to the contrast ground, I restarted. The LCD worked perfectly in displaying my message for LCDprint. But when WinLCD loaded, I just got a garbled message.

    Now my questions,
    Do you think there is just another short elsewhere on a line that isn't used for LCD print?

    Did I mess up my LCD permanently?

    Or... I just realized something. I threw in an HP scanner parallel cable to lengthen the cable. Does anybody know if this cable is not straight through? Could that be my problem? (Slaps himself for not testing unit with cable beforehand!)

  2. #2
    Low Bitrate
    Join Date
    Apr 2002
    Location
    Lafayette, LA
    Posts
    79
    Ok... Actually the cable I'm using is not an HP Scanner cable but rather a cable I found in my house. No labeling. But it appears to be straight through. I think I might have found the problem.

    I inserted the HP parallel cable before the other parallel cable to see if it would fix anything. Instead, it made things worse. Now... Is it possible that the distance of Parallel cables is causing my problem? I took out the HP cable and the LCD got better, but the display for winamp was still very messed up. Does anybody have an answer?! I'm going crazy here because my LCD is totally not working!!!

  3. #3
    Rob
    Rob is offline
    Maximum Bitrate Rob's Avatar
    Join Date
    Aug 2001
    Location
    Missing In Action
    Posts
    779

    More Dead Kittens

    This might help

    Rob (Savior of young inocent cats)
    And you say people actually pay money for M$ Windows?
    www.mp3mini.co.uk (Does what it says on the URL) www.openclassic.co.uk (The new car, with zero rust!) www.rob-web.co.uk (My other site)
    Total re-design underway: on the whole progress is very slow as the car is taking up too much time :)

  4. #4
    Low Bitrate
    Join Date
    Apr 2002
    Location
    Lafayette, LA
    Posts
    79
    Does anybody sell a premade circuit so that I can extend a parallel cable or do I have to make my own?

    I see the circuit on your website, but where would I get those chips? From Maxim?

    I know it's the length because another cable just screwed it up more.

  5. #5
    Rob
    Rob is offline
    Maximum Bitrate Rob's Avatar
    Join Date
    Aug 2001
    Location
    Missing In Action
    Posts
    779
    Probably have to make your own, I think I got the chips from either Farnell or National , of course you could allways try Maxim for free samples.

    Rob
    And you say people actually pay money for M$ Windows?
    www.mp3mini.co.uk (Does what it says on the URL) www.openclassic.co.uk (The new car, with zero rust!) www.rob-web.co.uk (My other site)
    Total re-design underway: on the whole progress is very slow as the car is taking up too much time :)

  6. #6
    Low Bitrate
    Join Date
    Apr 2002
    Location
    Lafayette, LA
    Posts
    79
    Anybody else have any option for this application?

  7. #7
    jol
    jol is offline
    FLAC jol's Avatar
    Join Date
    Jan 2002
    Location
    Mellansel, Sweden
    Posts
    1,299
    I Installed my pc in the car yesterday too, i got the same garbage as when i used a floppy cable for the wiring, (hey, its my thread i'ts referring to )

    anyways i tried a shorter cable and it worked, now i just gonna find a long, hi-quality cable.... I'll try to shield the one i have first with aluminum foil, will post results later.

    if it dont work i'm interested in the line driver chips that rob told us about, please post the schematics here so I can get a grip on how much work it is... if it's beyont me i'm interested in a pre-built one, if anyone would consider(?spell?) making me one, for money

  8. #8
    Rob
    Rob is offline
    Maximum Bitrate Rob's Avatar
    Join Date
    Aug 2001
    Location
    Missing In Action
    Posts
    779
    And you say people actually pay money for M$ Windows?
    www.mp3mini.co.uk (Does what it says on the URL) www.openclassic.co.uk (The new car, with zero rust!) www.rob-web.co.uk (My other site)
    Total re-design underway: on the whole progress is very slow as the car is taking up too much time :)

  9. #9
    Maximum Bitrate Raas's Avatar
    Join Date
    Jan 2001
    Location
    The Netherlands
    Posts
    626
    I have my 4x40 from EIO on a printercable of 4,5m (13-14ft).
    I never got any garbage on the display...
    Even not when I play with the sync-times and all..
    I can have my display update more than 20 times / sec, but never ever leaves garbage on the display...

    On my display I have a header pin, and there was a time when I got some garbage, and it turned out 2 data wires hit eachother now and then.. Have put some hotglue on it, and has been perfect ever since

    So you might have some short in some cable....

    Greetz,

    BTW.. the +5vdc which is used to power the display also runs through this printercable.. , even the wires for the keyboard,
    So all I have is a thick printercable running from the back to the front, but works beautifully.. on one end (front) it has got this old centronics connector which I use to hook up my control module (display + buttons + keyb. print) to the puter in the back..
    Cable at the back has 2 connectors.. 1 parallel, and one keyboard.
    The display itself is also retrieving its power from the keyboard connector..

    Hope this helps you out.!
    Greetz
    Raas - The Netherlands
    ME: VIA epia m10000, lilliput 7', opus 150w, 80gb<br>
    GF: IBM Thinkpad 380, ext. 3.5 80gb, 40x4, PB-IR

  10. #10
    jol
    jol is offline
    FLAC jol's Avatar
    Join Date
    Jan 2002
    Location
    Mellansel, Sweden
    Posts
    1,299
    rob i dont get it, i got 14 (data) connections, wich except data1-data7 should i connect

    lol i think i got i now...is data1-data7 enough do i have to amp up more?

Page 1 of 2 12 LastLast

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
  •