OpenMV cam h7 screen tearing

OpenMV Boards
1

Hi, I have just recently updated the firmware for cam h7 and I am experiencing screen tearing. It was fine before the update. Please advice.

2

H, which screen? The shield? There was never support to prevent screen tearing on that camera. If you didn’t see it before it means the frame rate was lower and the speed may have increased on image update.

3

I am experiencing screen tearing on the OpenMV IDE. I updated the firmware version from 4.5.2 to 4.5.5

4

Hi, does this happen with hello world?

I am traveling right now and won’t be able to test on an H7 board until Monday. But, can confirm there are no issues with an H7 Plus which uses the same camera driver code.

5

Hi, hello world works fine however there is screen tearing when I use another code such as camera, image processing, feature detection etc. I currently have 2 H7 (One of them is running on 4.5.5 and the other one is running on 4.5.2). The H7 running on 4.5.2 did not have screen tearing when I tested out the same code I used for the H7 running on 4.5.5.

6

Hi, I just retested the H7 Plus and H7 regular with the MT9M114, OV5640, OV7725, MT9V034, and FLIR Lepton and everything works as expected with 4.5.5.

I do not know what issue you are having.

7

Hi, the cam that is having screen tearing is M7 and not H7. My H7 which is running on 4.5.2 works fine but my M7 which is running on 4.5.5 has screen tearing. I apologise for the misinformation.

8

Hi, this is a bug. I know why it’s happening. It’s because we are invalidating processor-written data.

9

image
image694×530 87.2 KB

You’re seeing something like this?

This PR is breaking it. We didn’t test on the M7. Pull requests · openmv/openmv (github.com)

10

Have a fix for it: ports: Fix accidental CPU cache invalidation. by kwagyeman · Pull Request #2232 · openmv/openmv (github.com)

Please use this fixed firmware.bin for your M7.

firmware.zip (1.0 MB)

11

It works perfectly fine now. Thanks for the help :grinning: