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bitluni / ESP32-S3-VGA

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Screen shift #7

Open mylab4492 opened 9 months ago

mylab4492 commented 9 months ago

There issue that screen is shifted to right in higher resolutions like 800x600x60

BrainBoardz commented 8 months ago

I have encountered this as well. I put some resistors on VSYNC and HSYNC thinking that it might help with this. It didn't. This might be due to the slightly imprecise clocking of the sync signals.

bryaninkster commented 4 months ago

I have also found the horizontal shift problem on 800x600x60 and noticed the following aspects....

  1. The shift is random and often different when switched on from one time to another.
  2. It is not a hardware sync issue because when the signal is viewed on a 'scope, the video data is actually shifted w.r.t. the horizontal sync pulse but the line and frame rates are correct.
  3. It looks like the start address of the DMA is starting at a random (uninitiated?) value
  4. The display information wraps around so the end of the displayed page appears at the start of the screen
mylab4492 commented 4 months ago

its buffer issue I have also tried esp idf and it is quite stable there

On Sat, 2 Mar 2024 at 3:35 AM, bryaninkster @.***> wrote:

I have also found the horizontal shift problem on 800x600x60 and noticed the following aspects....

  1. The shift is random and often different when switched on from one time to another.
  2. It is not a hardware sync issue because when the signal is viewed on a 'scope, the video data is actually shifted w.r.t. the horizontal sync pulse but the line and frame rates are correct.
  3. It looks like the start address of the DMA is starting at a random (uninitiated?) value
  4. The display information wraps around so the end of the displayed page appears at the start of the screen

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