Getting started with OAK PoE devices

PoE allows a single Cat5e (or higher) Ethernet cable to be used to both power a device and give it connectivity at 1,000 Mbps (1 Gbps) full-duplex at up to 100 meters (328 feet).

https://user-images.githubusercontent.com/18037362/125928421-daed2432-73fb-4c5b-843e-037c7383a871.gif

After connecting the PoE device, the Ethernet connectivity LED (shown above) should turn on and start occasionally flashing.

Step by step tutorial

  1. You will need a PoE switch or Injector to power the PoE device. Click here for the full tutorial. After powering the device, LED should start blinking, as on the GIF above.

  2. Connect your computer to the same LAN as the PoE device.

  3. Make sure you have DepthAI version 2.7.0.0 or newer. You can update your DepthAI python package with python3 -m pip install depthai>=2.7.0.0

  4. Now you can run any code sample / depthai experiment / depthai_demo as you would when connecting an OAK device with a USB-C cable!

../../_images/poe-working.jpeg

After these steps, the depthai_demo is working on the OAK-D-POE!

How it works

When your app creates the device object (with dai.Device(pipeline) as device:), the library will search for available devices that are connected either by USB port or are on the LAN. It searches for PoE devices (UDP broadcast) on the same network and communicates with the device using TCP protocol. That way OAK PoE cameras work in the same manner as USB cameras. As with the USB-C connection, you can specify the Mx ID to specify to which OAK PoE camera you want to connect to (more info here).

Video streaming with OAK

Because an OAK PoE camera is connected to the internet, it can stream video feed directly to a computer. Here are two video streaming demos that use Script node (OAK PoE camera is needed), and can be run in Standalone mode:

Below are some demos which stream video feed from OAK camera via XLink to the host computer and then stream it from the host computer to another computer/server, which can also work with any other OAK camera (eg. USB line):

PoE enclosure

PoE enclosures are IP67 rated, so they are dustproof and waterproof. Make sure that the GORE vent isn’t blocked when you install the camera (especially outside), as it can lead to moisture fogging up in front of cameras (on the inside of the front cover).

../../_images/vent.png

PoE Troubleshooting

  • I can ping the OAK PoE camera, but can’t connect to it

    The DepthAI library only searches for available OAK PoE cameras inside the same LAN. If the camera is not in the same LAN, you would need to Manually specify device IP. Make sure that the camera has bootloader version 0.0.18 or newer flashed (we suggest using OAK Device Manager to check that) and that you are using depthai version 2.16.0.0 or newer. That’s because there were XLink device search improvements added on 2.16.0.0.

  • DHCP and Static IP

    By default, PoE devices will try to pull an IP address from DHCP. If a DHCP server isn’t available on the network, devices will fall back to static IP 169.254.1.222. In this static fall-back case, your computer will need to be in the same range. This can be achieved by setting a static IP on your computer (e.g. with static IP: 169.254.1.10 and netmask: 255.255.0.0).

  • Ports and Firewall

    UDP Device discovery is handled on port 11491, and TCP XLink connection is handled on port 11490.

    On Ubuntu by default the firewall is disabled, so you shouldn’t have any issues. You can check this though by executing the following command:

    > sudo ufw status
    Status: inactive
    

    If you have your firewall enabled, you might need to allow these two ports:

    sudo ufw allow 11490/tcp
    sudo ufw allow 11491/udp
    

    We have noticed that the above rules don’t always work as expected, and it’s sometimes necessary to run the command below. For production environment, you would want to set static IP on your OAK PoE camera, otherwise it could change and you would need to re-set the firewall rules.

    ufw allow from [OAK_POE_IP]
    
  • VPN connection

    VPN connectivity could also disrupt the connection with the PoE device (as your computer may be searching only the remote network for the device, so would be unable to discover it on the local network), so we suggest turning the VPN off when using the PoE devices or otherwise ensuring that your local routing is setup such that local devices are usable/discoveragle while VPN connectivity is active.

  • Connected to the same LAN via 2 interfaces (WiFi/ethernet)

    We have seen that in some rare circumstances when your host computer is connected to the same LAN, it can happen that device discovery finds the same PoE device twice, so it will print the IP address of that device two times. In some rare occasions this can lead to an error (we have seen this when using multiple devices) on initialization; RuntimeError: Failed to find device after booting, error message: X_LINK_DEVICE_NOT_FOUND. We will try to fix this bug as soon as possible. Workaround solution: disconnect from one of the interfaces; so disconnecting (from the) WiFi should resolve this issue.

  • Insufficient power supply

    If your PoE device does not work, or in some rare cases, it works for a period of time and then suddenly stops working, there might be an issue with your PoE switch. For example, when the power budget per port seems to be sufficient, but the overall power budget for the switch is being exceeded due to demands from devices on other ports. It is worth checking the specifications of your PoE switch / injector with respect to its overall power budget.

  • “Special” network equipment

    We have noticed that with certain network equipment, our 15 seconds timeouts for connecting to the POE deviceare insufficient, and need to be increased. You can increase these by using environmental variables (values in miliseconds).

    DEPTHAI_WATCHDOG_INITIAL_DELAY=60000 DEPTHAI_BOOTUP_TIMEOUT=60000 python3 script.py
    
    $env:DEPTHAI_WATCHDOG_INITIAL_DELAY=60000
    $env:DEPTHAI_BOOTUP_TIMEOUT=60000
    python3 script.py
    
    set DEPTHAI_WATCHDOG_INITIAL_DELAY=60000
    set DEPTHAI_BOOTUP_TIMEOUT=60000
    python3 script.py
    

Flash static IP

You can flash static/dynamic IP of an OAK-PoE device, demo here. You can also specify DNS and MAC address, but that’s not included into this demo.

Manually specify device IP

In case you are able to ping the device but the autodiscovery doesn’t work (eg. device itself isn’t in the same LAN), you can manually specify the IP address of the PoE device.

import cv2
import depthai as dai

pipeline = dai.Pipeline()

camRgb = pipeline.createColorCamera()

xoutRgb = pipeline.createXLinkOut()
xoutRgb.setStreamName("rgb")
camRgb.preview.link(xoutRgb.input)

device_info = dai.DeviceInfo("169.254.1.222")
# device_info = depthai.DeviceInfo("14442C108144F1D000") # MXID
# device_info = depthai.DeviceInfo("3.3.3") # USB port name

with dai.Device(pipeline, device_info) as device:
    qRgb = device.getOutputQueue(name="rgb", maxSize=4, blocking=False)
    while True:
        cv2.imshow("rgb", qRgb.get().getCvFrame())
        if cv2.waitKey(1) == ord('q'):
            break
#include "depthai/depthai.hpp"

int main(int argc, char** argv) {
    dai::Pipeline pipeline;
    auto camRgb = pipeline.create<dai::node::ColorCamera>();

    auto xoutRgb = pipeline.create<dai::node::XLinkOut>();
    xoutRgb->setStreamName("rgb");
    camRgb->preview.link(xoutRgb->input);

    auto deviceInfo = dai::DeviceInfo("169.254.1.222");
    // auto deviceInfo = dai::DeviceInfo("14442C108144F1D000");
    // auto deviceInfo = dai::DeviceInfo("3.3.3");

    dai::Device device(pipeline, deviceInfo);

    auto qRgb = device.getOutputQueue("rgb");
    while(true) {
        cv::imshow("video", qRgb->get<dai::ImgFrame>()->getCvFrame());
        int key = cv::waitKey(1);
        if(key == 'q' || key == 'Q') return 0;
    }
    return 0;
}

Note that if OAK is already running flashed pipeline, you need to change device info XLink state to X_LINK_FLASH_BOOTED in order to reach flash booted OAK camera.

Factory reset

In case you can ping the device but can’t connect to it in any way (search for the device, specifying IP), you should do a factory reset as the device might have been soft-bricked. This usually happens with older bootloader versions. Note that only OAK-D-PoE and OAK-1-PoE have a USB-C connector, while OAK-D Pro PoE has USB connectivity via M8 connector.

  1. Open the enclosure of your OAK PoE camera.

  2. Locate the USB-C connector and boot DIP switch.

  3. Change DIP switch to 0x16 (switches 2,4,5 are up, others are down, as on the image below) for USB communication.

  4. Connect OAK PoE camera via USB-C cable to the computer.

  5. Run the (first) Factory Reset script.

  6. Change DIP switch back to 0x3 (switches 5,6 up, others down) for PoE communication.

  7. Close back the enclosure, making sure the gasket is in the correct place (for waterproofing).

https://user-images.githubusercontent.com/18037362/154956812-c3fcc961-af46-4dfd-8080-e15c8c6b43f0.png

Got questions?

We’re always happy to help with code or other questions you might have.