MIPI / CSI Camera sync to flashing LED

Hey, Im trying to sync a MIPI camera to a flashing LED, I have setup a switch that allows me to control the LED quickly (HIGH and LOW commands) with low voltage GPIO, but I couldn’t find a lot of info on how to sync it with a MIPI / CSI camera.
I heard a lot of stuff about vsync and frame start / end if anyone could point me in the right direction it would be great.
My plan is to integrate this with Python and OpenCV so if there is a way to do this with Python / OpenCV it would be perfect.


Could you elaborate your usecase? Why do you think this issue is related to vsync?

Im trying to detect reflection tape by taking 2 frames, one with an LED on, and one with the LED off, subtracting the two frames and checking the result.
I couldn’t find any information as to how I can sync the LED flashing to the camera, so I was wondering if it is at all possible and if so whats the best way to do it? does the camera provide some sort of frame start / end signal?

I guess there is nothing related to vsync,right? Vsync is a term for display rendering but not for camera.

The camera on tegra didn’t support flash. However you can take LED as torch on before camera capture and turn it off after capture done. There’s no any sync mechanise for tegra camera framework.

Its probably not related to vsync, Im just trying to figure out if there is any way at all to achieve what Im trying to do with a jetson CSI Camera (syncing an LED that can be controlled via GPIO to the camera).

Just to be clear, the LED has to be on for one frame and off for the 2nd with perfect sync.

It’s difficult for current camera framework to sync the frame with LED. The safe way is turn on the LED before start stream and off after stop stream.

That defeats the point, I need to recieve 1 frame with the LED on and another frame with the LED off in order to subtract them and check the difference. There isnt any way to tap into frame start / end events for example? Or maybe sync them to a gpio?

I would to tell current implement can’t reach your request.

I cant even do something like the raspberry pi does? (https://www.raspberrypi.org/forums/viewtopic.php?t=190314)
Theres abosultely nothing that allows me to recieve a frame start or end event in any way at all?

Sorry NV didn’t support flash for L4T.