Dear Experts,
I would like to know what are the options (either software or hardware, similar to Intel Realsense) for synchronizing the timestamp of multiple OAK-FFC-4P based cameras connected to the same host via USB ports, please ?

Thanks in advance and best regards,
Khang

    Hi l4es
    I'd suggest looking through this guide for hardware synchronization. Hardware wise, i think your only option is connecting the fsin (https://docs.luxonis.com/projects/hardware/en/latest/pages/guides/sync_frames/#oak-ffc-4p-fsin) of multiple devices together, then set one to be the driver of the strobe (master) and the others as slaves. This would ensure the images are being taken at the same time.

    Software wise, you should probably do timestamp syncing as done in this example.

    Thoughts?
    Jaka

    • l4es replied to this.

      Hi jakaskerl ,

      For the hardware way, again, my setup is OAK FFC 4P with the AR0234 and this later does not work as master to drive other slaves. And I would like to drive all the AR0234 connected to different OAK FFC 4P (and configured as slaves) from a GPIO of the RVC2. Is it possible?

      Best Regards,
      Khang

      • erik replied to this.

        Hi l4es ,
        Software: If you are OK with 1/(FPS*2) (so 16ms at 30Hz) time delay, then you can use timestamp based syncing. All OAK-FFC-4P have synced clock (+- 1ms, if they are connected to the same host), so you can then sort/sync all messages on the host based on the timestamp, example here.

        Hardware: Wire up all AR0234 FSYNC lines from all OAK-FFCs together, then trigger it. It's a bit hacky (compared to OAK cameras with M8 connector and M8 Y-splitter), but it should work. Here are a few examples:

        OAK-D-Pro-PoE with external signal generator

        1. the exposure time low (manual exposure set), so TS difference (we display middle of the exposure):
        2. Auto-Exposure, so TS difference is a bit larger (13ms), as color sensors have 25ms longer exposure time (and we take middle of exposure, so /2)

          Wiring:

        OAK-D-SR-POE with M8 Y-splitter

        OAK-D-SR-POE has updated M8 logic, so they accept 5v on output-input (while old M8 logic required 10v on input, that's why we used signal gen.). This means one SR-POE can be the "master" (outputting FSYNC signal), while others down the "M8 Y-adapter daisy-chain" would be "slaves".

        I don't have any images of them looking at stopwatch, but all OV9782 were HW synced together.

        Thoughts?

          Hi erik ,
          THanks very much for your sharing. I prefer the hardware way:

          Hardware: Wire up all AR0234 FSYNC lines from all OAK-FFCs together, then trigger it. It's a bit hacky (compared to OAK cameras with M8 connector and M8 Y-splitter), but it should work.

          I would like your confirmation that in case I have multiple OAK FFC 4P + AR0234 based cameras, only one camera (so-called master camera) triggers its own AR0234 and the AR0234 of other sensors as well?

          Best Regards,
          Khang

          • erik replied to this.
            a year later

            toon
            Could you open a new thread please with information about the device (revision) and the cameras used?

            Thanks,
            Jaka

            • toon replied to this.