• DepthAI

  • Sometimes can't connect when using multiple cameras

Hi, When I try connecting to multiple cameras I can usually connect to them all, but sometimes I can't connect to a few of them. I've noticed it happening more often when I quickly restart my program. I'm using OAK-1 PoE cameras, and I still have this issue even after updating the bootloader and depthai versions.

I am running each device in its own thread, and from what I can tell, sometimes some of the threads just get stuck trying to connect to a camera. I made sure to include:
os.environ["DEPTHAI_WATCHDOG_INITIAL_DELAY"] = "60000"

os.environ["DEPTHAI_BOOTUP_TIMEOUT"] = "60000"

  • jakaskerl replied to this.

  • I think checking to see if the device is in the bootloader state first fixed it.
    # Check every second for new devices
    while True:
    device_infos = dai.Device.getAllAvailableDevices()
    for device_info in device_infos:
    if device_info.state != dai.XLinkDeviceState.X_LINK_BOOTLOADER:
    continue
    # Start thread here
    sleep(1)

    Hi Penguinmon

    Penguinmon I've noticed it happening more often when I quickly restart my program.

    How quickly are we talking about? Do you notice any improvements with changed watchdog delay as opposed to the standard configuration?
    Could you add a MRE of how you are connecting to the cameras on different threads?

    Thanks,
    Jaka

        Quickly like if I stop the program, wait a few seconds, then restart it.

        I just tried testing it in one of my projects using three cameras:
        I ran it twenty times using docker compose restart, and there were only two times where I couldn't connect to all of the cameras (one different camera each time)
        I didn't notice any difference with the watchdog delay in this case. I just made a habit of putting it in my projects because there are some cases where I need it.

        I'll see if I can get an MRE.

        I think checking to see if the device is in the bootloader state first fixed it.
        # Check every second for new devices
        while True:
        device_infos = dai.Device.getAllAvailableDevices()
        for device_info in device_infos:
        if device_info.state != dai.XLinkDeviceState.X_LINK_BOOTLOADER:
        continue
        # Start thread here
        sleep(1)

          4 days later

          Penguinmon
          Could you share your code?

          I've been trying to skirt-around using the DEPTHAI_WATCHDOG_INITIAL_DELAY=60000 DEPTHAI_BOOTUP_TIMEOUT=60000 python3 script.py flags you can pass on but that also didn't work.

          Much appreciated.

              The_Real_Enrico_Pallazzo
              I'm not sure if it's the best way to do it, but this is how I've been connecting to multiple devices: https://paste.modprog.de/adSu

              There are also some depthai examples that I looked at previously:
              https://docs.luxonis.com/projects/api/en/latest/samples/mixed/multiple_devices/#multiple-devices
              https://github.com/luxonis/depthai-experiments/blob/master/gen2-multiple-devices/main.py

              Setups:
              Pi (running a dhcp server) <--> Unmanaged PoE switch <--> PoE Cams
              PC <--> Managed PoE switch <--> PoE Cams

                  Penguinmon
                  I've tried all the docs and the --experiments/gen2 to no avail….except one time a single cam magically worked….out of 40+ tries….

                  I'll be trying your dnsmasq tomorrow….maybe it works.