Connect with us

LVDS signal from an FT812

Discussion in 'General Electronics Discussion' started by NeX, Jan 24, 2017.

Scroll to continue with content
  1. NeX

    NeX

    1
    0
    Jan 24, 2017
    Hi everyone, this is my first post

    i am hoping to get some outside help on a project i have been working on. i am trying to drive an LCD which uses an LVDS interface, with an FTDI F812 graphics processing chip.

    this is the datasheet for the display:http://www.vslcd.com/Specification/LQ123K1LG03.pdf

    and this is the datasheet for the FTDI chip: http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT81x.pdf

    i am using an ID250 TTL to LVDS converter board, here is the datasheet: http://www.ibt.ca/v2/items/id250/id250userguide.pdf
    and the datasheet for the actual chip on board: http://www.ti.com/lit/ds/slls271i/slls271i.pdf


    i have triple checked the wiring and i am confident it works, the LCD works with an external driver board and the FTDI works with other displays, but if i try and drive the LCD with LVDS is just flickers a bit.

    i have used a 10Mhz crystal for the FT812 to bring the speed in sync with what the LCD is expecting, and i have set the FTDI up with these settings:

    REG_HCYCLE, 1688
    REG_HSYNC0, 400
    REG_HSYNC1, 4
    REG_HOFFSET, 408
    REG_VCYCLE, 525
    REG_VSYNC0, 40
    REG_VSYNC1, 4
    REG_VOFFSET, 45
    REG_HSIZE, 1280
    REG_VSIZE, 480
    REG_CSPREAD, 0
    REG_PCLK_POL,0
    REG_PCLK, 2

    this is the best settings i could work out from the datasheets. unfortunately i have no scope and only a cheap chinese logic analyser so i am kinda going blind on this one.

    if anyone has any ideas or can think of anything else i would really appreciate it. i have just ordered a different TTL to LVDS chip: https://4donline.ihs.com/images/Vip...6-1.pdf?hkey=EF798316E3902B6ED9A73243A3159BB0

    so maybe i will have better luck with that, but until it arrives i still want to see if i can get what i have here working.

    thanks!
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-