Camera OV2640 - instable JPEG stream

atlascoder
Posts: 28
Joined: Wed Aug 30, 2017 12:36 pm

Camera OV2640 - instable JPEG stream

Postby atlascoder » Fri Jun 21, 2019 3:48 pm

Hello!

I am trying to use OV2640 camera with ESP32. I used different hardware - M5Cam, custom boards, ESP32 and ESP32-PICO-D4 and in all cases I can't get stable JPEG picture.

I tried esp32-cam-demo (https://github.com/igrr/esp32-cam-demo) and different forks - no luck.

The camera works OK some time, but then it starts to emit broken images. Very similar issue is described here https://forums.openmv.io/viewtopic.php?t=24 but for STM backend.

I know that JPEG is huffman encoded data and if to chenge even a single bit - it will corrupt the whole picture to not-dsplayable form with very high chance. And I checked this by manual changing of bits in any JPEG file - almost always it makes it broken - not displayable.
But in my case I have different - frames are always being displayed, but picture has shifted areas - like with the issue on STM before.
So I suspect, that picture gets broken before compression - somewhere in camera.

I checked all signall lines to camere on noises - and signals looks very good. Changing of XCLK - does not resolve the issue.

What's more interesting - I can't find any topic about this on the Web. And I could think that it something in my hardware, but believe, I used at least 5 different boards with different cameras and used esp32-cam-demo without changes.

Had anybody faced the same? Where is the cause? I've exhausted all ideas :cry:

fistvan
Posts: 1
Joined: Tue Sep 10, 2019 9:30 am

Re: Camera OV2640 - instable JPEG stream

Postby fistvan » Tue Sep 10, 2019 9:33 am

I have exactly the same problem. Working on it. Any success your end since?

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