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LVDS signal from an FT812

NeX

Jan 24, 2017
1
Joined
Jan 24, 2017
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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!
 
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