DCMI DMA interrupt callback

[gokhannsahin]

Hi everyone,

I have tried to get image data through DCMI module and transmit to the external graphics memory FT812. However, the MCU get never DMA callback after started although the camera signals can be seen at pins. The DMA handle keeps always on busy state. P.S: I have no external SDRAM, using internal SRAM on MCU for getting image data.

uint8_t buff[30*1024];
HAL_DCMI_Start_DMA(&hdcmi, DCMI_MODE_CONTINUOUS, (uint32_t)buff, 30*1024/4); 

[gokhannsahin]

I found out the problem. It's about hardware and D0 and D1 were short circuit. 😀

But I have another question about DCMI module. I'm using OV5640 and it supports JPEG mode.

I don't know how to calculate the total image size recieved camera and total line size?(It's being used 640x480.)

[MLENG.1]

Hi gokhannsahin,

as far as I know the image size is part of the header of the jpg file. So if you are able to receive a complete picture from the OV5640 cam via DCMI a jpg decoder should be able to decode the picture.

Regards Manfred