[SOLVED] DPI colors messed up with LQ35NC111 screen

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Sushi
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[SOLVED] DPI colors messed up with LQ35NC111 screen

Post by Sushi » Sat Feb 10, 2018 3:15 pm

I'm trying out a DPI setup on my pi. The problem is that my screen only shows white. I've used the screen's datasheet to setup the DPI timings and made sure it's been wired properly. Has anybody else experienced anything like this? Were you able to fix it?

I'm using the LQ35NC111. My config.txt has this at the end:

Code: Select all

dpi_output_format=458775		
hdmi_timings=320 1 20 30 38 240 0 4 3 15 0 0 0 60 0 4608000 1

enable_dpi_lcd=1
display_default_lcd=1	

dtparam=i2c_arm=off
dtparam=spi=off
Last edited by Sushi on Fri Feb 16, 2018 10:27 pm, edited 1 time in total.

salami738
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Re: DPI displaying white screen

Post by salami738 » Sun Feb 11, 2018 12:39 am

Sushi wrote:
Sat Feb 10, 2018 3:15 pm
I'm trying out a DPI setup on my pi. The problem is that my screen only shows white. I've used the screen's datasheet to setup the DPI timings and made sure it's been wired properly. Has anybody else experienced anything like this? Were you able to fix it?

I'm using the LQ35NC111. My config.txt has this at the end:

Code: Select all

dpi_output_format=458775		
hdmi_timings=320 1 20 30 38 240 0 4 3 15 0 0 0 60 0 4608000 1

enable_dpi_lcd=1
display_default_lcd=1	

dtparam=i2c_arm=off
dtparam=spi=off
Hi, kite used exact this screen in his custom board. Please try his settings https://github.com/kiteretro/Super-AIO/ ... config.txt

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Sushi
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Re: DPI displaying white screen

Post by Sushi » Fri Feb 16, 2018 10:27 pm

I've got an image now! Thanks! There's just one issue: I get no red channel and the colors look crazy :(
Take a look at what I mean:
ImagesShow
IMG_0779.JPG
IMG_0779.JPG (2.65 MiB) Viewed 2811 times
IMG_0777.JPG
IMG_0777.JPG (2.48 MiB) Viewed 2811 times
It's possible that it's wiring, though I went over it at least 5 times to make sure it wasn't that. It looks as though greens are blue, reds are green and there are no blues to be replaced with reds.

I used this reference for the Pi's pins and this datasheet for the displays.

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moosepr
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Re: DPI colors messed up

Post by moosepr » Sat Feb 17, 2018 6:02 am

There are different colour modes for the DPI screens

You need to adjust the dpi_output_format so that it is the different modes. I found this post, http://blog.reasonablycorrect.com/raw-dpi-raspberry-pi/ (nod to electriccrowbar on discord) and in this post he has a link to a spreadsheet that helps you to calculate the value you need

https://docs.google.com/spreadsheets/d/ ... sp=sharing

This is how I managed to fix mine 😀
Get a small cheep LCD in your project https://www.sudomod.com/forum/viewtopic.php?f=22&t=2312
Wrap it all round a battery https://www.sudomod.com/forum/viewtopic.php?f=13&t=2292
Or use a custom PCB to make it really small https://www.sudomod.com/forum/viewtopic.php?f=13&t=2512
or make it really really really really tiny!! https://www.sudomod.com/forum/viewtopic.php?f=13&t=2919

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Sushi
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Re: DPI colors messed up

Post by Sushi » Sat Feb 17, 2018 1:14 pm

I fixed it :D

The problem was that I'd wired for 888, but was outputting 666. Thanks!

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Re: DPI colors messed up

Post by VeteranGamer » Sat Feb 17, 2018 1:15 pm

Sushi wrote:
Sat Feb 17, 2018 1:14 pm
I fixed it :D

The problem was that I'd wired for 888, but was outputting 666. Thanks!
ahhh the ole 666.... :twisted:


.

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Re: [SOLVED] DPI colors messed up with LQ35NC111 screen

Post by YaYa » Sun Feb 18, 2018 6:19 am

Changed the topic's title to something more relevant and moved it to the solved forum :D
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