STM32H7 DCMI DMA half image

Dear Forum,

I hope I am not off topic but here are the best STM32H7 DCMI knowledge

I am trying acquire VGA RAW Bayer data from OV7670 to Nucleo-H745
Something very strange happens: in one transfer I get only upper half of the image, and in the following transfer I get the lower half of the image… and so on… (the sensor is tilted 90deg in the attached pic). If I acquire QVGA everything is ok.

Have you ever encountered a similar situation? where should I look for the issue ?

Thank you


I’d probably check how our driver works:

It sounds though like your transfer size is wrong and DMA is still running.

1 Like

Hi Kwagyeman,

Thank you for your feedback,

After receiving my usb oscilloscope I could have a look to the signals.
I suspect I have only 240 lines, even if are 640 PCLK cycles per line… as it the resolution is 640x240 rather than 640x480 as intended.
Do you know what could cause this?

Thank you


I know you need help here… but, there’s like a million things that can go wrong. I can’t possibly debug your issue.

So, I recommend to look at how our driver works and how yours does. Note that you need to look at our HAL too as we’ve patched bugs in it.