nanoSwiss
Posts: 3
Joined: Tue Oct 16, 2018 8:20 am

HDMI display only shows on half the screen

Tue Oct 16, 2018 7:36 pm

So here is my original intent, i wanted to make a portable audio player with osmc and the raspberry pi 3b. The screen i wanted to use is a 5'5inch display from china, here is the listing for it https://www.alibaba.com/product-detail/ ... 3e5fcCfnv8 but i could not get it to display on the hole screen.
I then tried it on raspbian because i considered it maybe being a problem with osmc. But this is the best that i got it after i changed some things in the config.txt file:
IMG_20181016_1015154.jpg
IMG_20181016_1015154.jpg (134.76 KiB) Viewed 150 times
I used the following settings:
  • overscan_left=-1000 (overscan_left did not do anything past -48)
    overscan_right=-48
    overscan_top=-48
    overscan_bottom=840
    hdmi_force_hotplug=1
    hdmi_group=2
    hdmi_mode=82
    hdmi_drive=2
    config_hdmi_boost=11 (no change at all)
    dtparam=audio=on
    display_hdmi_rotate=3
    gpu_mem=512 (saw someone recommend this on a forum but did not work)
I also tried the custom hdmi_mode but did not have any luck with that. here are some examples of what i tried:
  • hdmi_cvt=1920 1080 60 3
    hdmi_cvt=1080 1920 60 3
    hdmi_cvt=1920 1080 30 3
    hdmi_cvt=1920 1080 60
Its probably not the display, because it works on my Ubuntu 18.04 machine just fine. The only thing to mention is that the display has to be set in horizontal for it to work in landscape and vise versa.
I am working/browsing on this problem for some time now. And at this time i don't know what to try next and would appreciate any help

aBUGSworstnightmare
Posts: 1066
Joined: Tue Jun 30, 2015 1:35 pm

Re: HDMI display only shows on half the screen

Wed Oct 17, 2018 10:34 am

Fiddling around with oversan will not solve your problem, as your problem is incorrect timing! Most likely the EDID data is not picked up corectly.

You can make a quick test by adding

Code: Select all

hdmi_ignore_edid=0xa5000080
to your config.txt

What I would suggest is asking your seller for the exact display timing and then use a custom hdmi_timings setting (as this should work in OSMC too).
https://www.raspberrypi.org/documentati ... t/video.md

I have a pair of Manga Screen 2 (5.9in FHD
To make it work correctly I also have to define framebuffer size

Code: Select all

max_framebuffer_height=1920
# settings for MANGA SCREEN 2
hdmi_force_hotplug=1
hdmi_ignore_edid=0xa5000080
# ---------------------------------------------
# custom HDMI mode
# ---------------------------------------------
hdmi_group=2
hdmi_mode=87

# ---------------------------------------------
# HDMI timing definitions
# ---------------------------------------------
hdmi_timings=1080 1 100 10 50 1920 1 2 2 2 0 0 0 60 0 144400000 3
Note: this seems to be your display http://www.panelook.com/TA055FHV02-new- ... 65665.html#

nanoSwiss
Posts: 3
Joined: Tue Oct 16, 2018 8:20 am

Re: HDMI display only shows on half the screen

Wed Oct 17, 2018 7:45 pm

First of all thank you, you already helped me a lot. It looks like this is indeed the problem.
I did a bit of research on HDMI timings on general because i did not know anything in this topic at all.
I got a spec sheet for my display, here is a pdf https://sc01.alicdn.com/kf/HTB1Gp5ZXiDx ... cation.pdf On page 13 and 14 there are "Timing Parameters" but i could not make any sense out of those numbers.
Trying your settings out of desperation did help, the mess on the bottom is now gone and the hole thing moved to the middle + i don't have to overscan for the display to not extend over the side. but it still does not fill the screen. modifying your settings only made the result worse. i searched the web some more and came across sites like this https://timetoexplore.net/blog/video-ti ... 720p-1080p where some standard settings where written that i copied. Sadly i did not have any luck with these as well.
I am going to do some more research tomorrow and write again if i make any progress.
In the meantime i am thanking you again for your help so far.

nanoSwiss
Posts: 3
Joined: Tue Oct 16, 2018 8:20 am

Re: HDMI display only shows on half the screen

Sat Oct 20, 2018 5:58 pm

So quick update, if got it working now.
Thanks for the help aBUGSworstnightmare you are awesome.

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