Lag when using 7" touch screen.

Is the sound coming from the HDMI connection or through a jack?

Hi Will,

This is a repeat of a question you've asked (and which was responded to) earlier:

Laggy Element 14 7" PI touch screen

I read your response and appreciate your advice. Read the comments above your post on the previous question.

Hi Will,

I have read the comments. There's a comment stating that the 'Raspberry pi' space should be used, but your original post has been moved to that space.

You've now got two threads on the same topic, in the same space.

Oh, I didn't know it was moved. Sorry 'bout that. Is there a way to delete one?

Hi Will,

I think the control to do that is somewhere at the top-right when viewing your discussion.

Anyway, It's no big issue, I just wanted to be sure that you'd seen the earlier response (some people don't respond, and then it's unclear if they did see the response, or accidentally missed it).

I don't know the answer, so just to give you something to work on meanwhile, I think it's almost definitely a sound related issue and not a display related issue (despite seeing the effect being lag on the screen). The lag on the screen is likely application related (not driver related) - I'm guessing the application may be waiting for audio to be played out (it is one possible code implementation, I don't know what the game emulator actually does), and timeouts as a result in the code could be causing the slower update. If there is an option to disable audio in the game emulator (just as a test) that could be worth trying out, to see if it improves the display output.

I don't know what the end solution is, other than trying to debug the audio (e.g. enabling verbose debug if the emulator supports it, or googling for resolving audio issues, it is beyond my knowledge area.

On Shabaz's advice I've started looking for audio problems alone that were like mine. Most of the threads/posts seem to be from 2013 or so. Like this one here. https://www.raspberrypi.org/forums/viewtopic.php?t=60353  Unfortunately the solution was to eliminate the component cable and only use HDMI.

This one from 2016 https://raspberrypi.stackexchange.com/questions/3626/how-to-get-better-audio-quality-from-audio-jack-output  has a work around using a USB audio device and some fixes here https://www.raspberrypi.org/forums/viewtopic.php?f=35&t=20445 from 2012.

Seems like this problem was fixed or should have been fixed. Newer posts having to do with audio have a lot of the same fixes , but for different problems. https://github.com/alexa-pi/AlexaPi/wiki/Audio-setup-&-debugging

After reading the negative reviews on Amazon it seems to me this screen should not be sold as an official Raspberry PI - plug and play.

Hi Will,

From the symptoms you described, it still seems like a RetroPie script or Raspbian image or sound driver issue.

I don't think it is anything to do with the display. The symptom likely has a different root cause basically, and the result is lag from the application itself (some of this is speculation - but it's a reasonable guess). You can test by trying to run an application that has no sound capability. If it runs with no lag (well, no lag compared to HDMI) then that's a strong indicator. Have you run such tests?

The display is a mature product (been available for several years) and is intended for kids to use to learn programming with the Pi.

Once you go beyond that and start loading up games emulators with sound capability, although it can work, I'm not overly surprised if it needs troubleshooting since whoever last updated the scripts or the drivers may not have tested that combination (display plus particular retropie script you're using).

As well as the test mentioned above, have you tried to disable audio capability in Retropie, as a temporary test to see if it resolves the lag from the application?