Using Video DMA on Ultra96

Hi everyone,
I would like to use a camera through a Ultra96 V2 with pynq 2.5. First, I want to show a fixed image (a test pattern). To do that, I have created an IP to deliver the image, to the PS part through a Video DMA (ref: image1).

Then using the pynq, I import the overlay and I open the axi_vdma. I had to modify the vdma driver because I don’t need any mm2s_introut or s2mm_introut (cf: Problem Using VDMA Driver With Only Write Channel - #9 by DarthSimpson)
image

Then, I would like to start the VDMA but I don’t have any argument like readchannel or writechannel.

Does someone have any ideas or tips to start the vdma and get the image?

Thanks for your answers,

William

Ps: I am quite new in fpga that’s why I use pynq


Image 1