topic Re: lvds display interlace on I.MX8M board in i.MX Processors

lvds display interlace on I.MX8M board

coindu — Thu, 28 Feb 2019 02:26:36 GMT

HI all

I meet some problem to display with dual lvds signal.

The screen resolution is 1920x1080 and finally display interlace. by write data to /dev/fb0 found some clues .

if i want draw a red line, which X axis=0, but it will display on X axis = 1.

if i want draw a read line, which X axis =1 , it will display on X axis = 0.

for(x = 0; x< height; x++){

draw vertical line which axis = X

}

the final display will be

1 0 3 2 5 4 7 6 ...... 1919 1918

| | | | | | | | ........ | |

has some parameter to fix it ？

Re: lvds display interlace on I.MX8M board

igorpadykov — Thu, 28 Feb 2019 05:25:26 GMT

Hi coin

there is no lvds on i.MX8M and it is necessary to use solution similar to

how to use ldb/lvds in android8 of imx8mq ?

Are you able to draw correctly using MX8-DSI-OLED1, described on

AN12189 MX8-DSI-OLED1 for i.MX 8M Evaluation Kit

https://www.nxp.com/docs/en/application-note/AN12189.pdf

Best regards
igor
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Re: lvds display interlace on I.MX8M board

coindu — Thu, 28 Feb 2019 06:08:59 GMT

thanks for your reply.

I use tc358775 IC to convert mipi-dsi to lvds signal. our bottom board has a fpc connector with single lvds for 1280x800 screen and a 40-pin connector with dual lvds for 1920x1080 screen. the little screen with 1280x800 resolution works well, but the big screen display blurry.

so write a display test to draw line on the screen. found the reason but i do not know to to deal with it.

Re: lvds display interlace on I.MX8M board

igorpadykov — Thu, 28 Feb 2019 10:38:37 GMT

one can try patches provided on link (Aug 23, 2018 12:14 AM)

i.MX8M EVK MIPI CSI Camera Frame Rate

If this will not help suggest to proceed with NXP Professional Services | NXP

Best regards
igor

Re: lvds display interlace on I.MX8M board

coindu — Fri, 01 Mar 2019 03:53:30 GMT

Thanks .

I tried to exchange LVDSA and LVDSB connection sequence ， the odd and even also follow the exchange . it it work and display normal now.