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Screen performance?

Posted: Wed Apr 19, 2017 11:05 am
by Robochris
Just finished my first build, turned out great! I'll put it up in the show off soon..

But first, my screen (which is BW var. 8) seems a bit fuzzy. Maybe grainy? Not sure how to explain it.. like it has the texture of old tv static. It moves, not just blurry. It's certainly playable and not too noticeable I guess.

I know these are pretty low res screens but is there any way to sharpen this? Maybe my connections?

Any of yours turn out this way?

Thanks!

Re: Screen performance?

Posted: Wed Apr 19, 2017 3:57 pm
by McGyver
Play with your groud: best would be to use a shielded composite connection. Maybe you find some old headphone wires or composite extensions. Second: connect the shield to the raspberry ground next to the composite pad. If no effort try any other grounds in your power distributions.

Re: Screen performance?

Posted: Wed Apr 19, 2017 8:26 pm
by Robochris
McGyver wrote:
Wed Apr 19, 2017 3:57 pm
Play with your groud: best would be to use a shielded composite connection. Maybe you find some old headphone wires or composite extensions. Second: connect the shield to the raspberry ground next to the composite pad. If no effort try any other grounds in your power distributions.
Thanks! I'll give it a go!

Re: Screen performance?

Posted: Wed Apr 19, 2017 9:06 pm
by fraggle
You could try forcing the frame buffer to the resolution of the screen. What I have found is that quite a few of the 3.5" composite screens are not actually 320 x 240 - they are a little under - for example the ones I have are actually 320 x 234.

To set the frame buffer open up /boot/config.txt and uncomment/modify the following lines to match your screen resolution.

Code: Select all

framebuffer_width=320
framebuffer_height=234

Re: Screen performance?

Posted: Wed Apr 19, 2017 9:18 pm
by Robochris
fraggle wrote:
Wed Apr 19, 2017 9:06 pm
You could try forcing the frame buffer to the resolution of the screen. What I have found is that quite a few of the 3.5" composite screens are not actually 320 x 240 - they are a little under - for example the ones I have are actually 320 x 234.

To set the frame buffer open up /boot/config.txt and uncomment/modify the following lines to match your screen resolution.

Code: Select all

framebuffer_width=320
framebuffer_height=234
How do I find my exact resolution?

Re: Screen performance?

Posted: Wed Apr 19, 2017 9:25 pm
by fraggle
Did the screen come with any kind of data sheet or packaging, maybe the manufactures website?

If not then try running:

Code: Select all

xrandr | fgrep '*'
It should list the actual resolutions the screen supports (the current one will be marked with an asterisk).

Re: Screen performance?

Posted: Sat Apr 29, 2017 4:43 pm
by lifeinkyoto
Hey. Think I'm having the same problem. Looks a bit like the image attached.

Re: Screen performance?

Posted: Mon May 01, 2017 12:35 am
by Kalei808
I had the same problem.what i did to fix it; Ground to the pi, Ive used a composite (rca) single shielded wire from vid1 and ground from lcd driver board to the pi tv out and the ground next to the tv out on the pi. Screen is perfect now with no fuzzy lines, just crisp. Good luck

Re: Screen performance?

Posted: Mon May 01, 2017 6:26 am
by VeteranGamer
Kalei808 wrote:
Mon May 01, 2017 12:35 am
I had the same problem.what i did to fix it; Ground to the pi, Ive used a composite (rca) single shielded wire from vid1 and ground from lcd driver board to the pi tv out and the ground next to the tv out on the pi. Screen is perfect now with no fuzzy lines, just crisp. Good luck
i can second that....

i went back and changed the wiring after my build was finished (my son complained that the screen was having intermitten interference)


used an old rca lead lying around

Image


your board may vary but the principle is the same

Image



now the screen is crisp (as can be expected) and no interference

Re: Screen performance?

Posted: Mon May 01, 2017 1:37 pm
by onesojourner
VeteranGamer wrote:
Mon May 01, 2017 6:26 am
Kalei808 wrote:
Mon May 01, 2017 12:35 am
I had the same problem.what i did to fix it; Ground to the pi, Ive used a composite (rca) single shielded wire from vid1 and ground from lcd driver board to the pi tv out and the ground next to the tv out on the pi. Screen is perfect now with no fuzzy lines, just crisp. Good luck
i can second that....

i went back and changed the wiring after my build was finished (my son complained that the screen was having intermitten interference)


used an old rca lead lying around

Image


your board may vary but the principle is the same


Image



now the screen is crisp (as can be expected) and no interference

I also had this same problem. I had super flacky/bad screen performance. This totally fixed the issue. I think this should be a sticky.