Camera OV2640 - instable JPEG stream
Posted: 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
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