How are the multi- AR0231 cameras synced in stream mode?

Autonomous Vehicles DRIVE PX 2 DRIVE Hardware
1

Which mode does the AR0231 camera work on, stream mode or trigger mode?

we have read AR0231 RCCB sensor driver isc_ar0231_rccb_setting.h, and found reg 0x301A was set as 0x19DC which means the R0x301A[2] = 1. and we think it is Stream mode.
and also I disassembled the AR0231 camera and short the trigger signal to ground , all 4 cameras still work very good.

As I know, the different cameras have different clocks(tolerance ), in theory, they will become loss of sync.

So the questions comes, if they don’t work on trigger mode, how does they synced in stream mode?

Thanks
Best regards
Yantao

2

Dear ytdong,

They are all operating in trigger mode & synchronized per deserializer. Thanks.

3

Hi SteveNV, Hi ytdong,

I’m also interested in this topic.

@SteveNV: Could you please go a little bit more into the technical details?

  • How is the triggering done? (e.g. Does the deserializer send a signal to the cameras?)
  • Do the cameras support triggering? (Support from Leopard Imaging told me, that the driver of LI-AR0231-GMSL does not support triggering yet)
  • If using several cameras, how accurate is the synchronization of the cameras?
  • As you said the deserializer synchronizes the cameras → If I understand correctly, there is no need for an external trigger box.

Thank you for the details in advance.

Best regards
Robin

4

Hi, SteveNV,
Hi,Robin

I tested the trigger pin of AR0231,there is a 30Hz pulse on it,
so I used to believe the cameras work on trigger mode.

Then I short it to ground, which means no trigger provided to sensor, but the cameras still work.
so I think they are not working at trigger mode.

So could you please give a little bit more about the details about how the AR0231 cameras be synchronized.

Best regards
Yantao