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Lower refresh rate from LCD, is it possible to increase it? - Printable Version

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Lower refresh rate from LCD, is it possible to increase it? - Itzpi3 - 03-01-2018

At first I thought my FPZ wasn't performing as expected with games stuttering a bit sound choppy etc. When I run the same games connected to HDMI the game play is a smooth 60 FPS. same results with every NTSC based rom I've tested. I've installed rfkill and disabled wifi and bt but there's no difference. Is it possible to increase the refresh rate of the LCD?


RE: Lower refresh rate from LCD, is it possible to increase it? - Flavor - 03-01-2018

When you say that you run the games connected to HDMI, what do you mean? It doesn't make sense that you would just plug in HDMI and the sound would improve. You must be doing something else, too.

What emulator/system are you noticing this with?

You can change some LCD parameters. In /boot/freeplayfbcp.cfg you can tweak some things. It looks like this.
https://github.com/TheFlav/rpi-fbcp/blob/master/freeplayfbcp.cfg

You could try setting FREEPLAY_SCALE_TO_VIEWPORT=0; (and then use the overscan parameters in config.txt) to see if that gives you any change.
You could try the FREEPLAY_FPS parameter.


RE: Lower refresh rate from LCD, is it possible to increase it? - Itzpi3 - 03-01-2018

What I mean is when I have the FPZ connected to my TV via HDMI the game play is smooth w/o stuttering on the TV, the FPZ stutters. quick example is screen transitions in Super Metroid, on the FPZ they animate as if I have frame skip set to 1 and on the TV it's set to 0. TBH I can't even get the audio to output via HDMI. I'm using the default emulators from the SD image. Every emulator runs like that even the Retropie menu isn't as smooth as it is on my TV.


RE: Lower refresh rate from LCD, is it possible to increase it? - Flavor - 03-01-2018

Oh. You had said "a bit sound choppy" and then you said using HDMI fixed it. I thought you meant that the choppy sound also went away with HDMI.

In /boot/config.txt you can change hdmi_drive=1 to 2. That should put audio on the HDMI, if you want it. Well, I think you'd then be able to select HDMI audio in the menu.

Try the FREEPLAY_SCALE_TO_VIEWPORT=0 I mentioned earlier. See if that helps. In the past rfkill has been the answer to these things. I'm not sure why it hasn't helped in your case.


RE: Lower refresh rate from LCD, is it possible to increase it? - Itzpi3 - 03-01-2018

I'm trying to edit the config file but it refuses to save using WinSCP

Permission denied.
Error code: 3
Error message from server: Permission denied.


RE: Lower refresh rate from LCD, is it possible to increase it? - Flavor - 03-01-2018

Yes, you're right. If you ssh in, you need to edit it as super-user. I'm not sure that you can do it via WinSCP.

try
ssh pi@retropie.local

On Windows, use PuTTY.

Once logged in
sudo nano /boot/config.txt
or
sudo nano /boot/freeplayfbcp.cfg


RE: Lower refresh rate from LCD, is it possible to increase it? - Itzpi3 - 03-02-2018

After getting root access etc I made the changes you suggested but I see no noticeable difference. Here's two examples of the issue I'm having


https://www.youtube.com/watch?v=DUV-wDOhIyo

https://www.youtube.com/watch?v=d6JCHJIgh8A


RE: Lower refresh rate from LCD, is it possible to increase it? - Flavor - 03-03-2018

Yes, I see what you mean, now. Is this only for a select few games?

Did you try changing
FREEPLAY_FPS = 60; //120 might be best visually, but lower uses less CPU
to
FREEPLAY_FPS = 120; //120 might be best visually, but lower uses less CPU
by any chance?

I will say that we are also working on a new way to copy the HDMI to the LCD that is much more optimized for the LCD we use, but I don't expect it to be ready real soon.

Also, you might look at https://github.com/recalbox/recalbox-os/wiki/TFT-Screen-SPI-Bus-(EN)#configure-your-waveshare-32-resistif-tft-screen under the "Waveshare 3,2" heading.
They suggest using "speed=82000000" on the dtoverlay=waveshare32b line and changing the HDMI parameters to
hdmi_force_hotplug=1
hdmi_cvt=320 240 60 1 0 0 0
hdmi_group=2
hdmi_mode=1
hdmi_mode=87

That MAY not work on your HDMI TV, but it could help the LCD.

Also, another thing to try is using the waveshare32b-fp that I have recently made available, to see if that helps at all.
See https://forum.freeplaytech.com/showthread.php?tid=4580&pid=6682#pid6682


RE: Lower refresh rate from LCD, is it possible to increase it? - Itzpi3 - 03-03-2018

It's pretty much that way for anything displayed on the LCD. Almost as if the LCD itself is refreshing at 30Hz. I'll go ahead and give your other suggestions a shot and get back with you with the results, thanks.


RE: Lower refresh rate from LCD, is it possible to increase it? - jsawhite - 03-03-2018

(03-03-2018, 09:39 AM)Itzpi3 Wrote: It's pretty much that way for anything displayed on the LCD. Almost as if the LCD itself is refreshing at 30Hz. I'll go ahead and give your other suggestions a shot and  get back with you with the results, thanks.

I'd actually come to the same conclusion (after trying to mess with the LCD settings suggested)...  it appears that either the LCD is a lower refresh rate, or I've also read that some LCD's, when connected to GPIO pins, are laggy...  not sure which.  I'm trying to see if I can find a different LCD I can make fit.  Maybe one that is composite and uses the video out on the pi...  Sad

I'd be really curious if any of the CM3 folks are noticing the same thing.  I would guess so, but not sure.