I recently acquired an OAK-D CM4 device. However, I can only run the depthai-demo.py script when connected via VNC to the Raspberry Pi CM4. Whenever I attempt to run it through the DepthAI app on Windows, I encounter the "no DepthAI device found" error. I'm wondering if there is a solution to this issue.

jakaskerl Thanks @jakaskerl now it is working completely on headless configuration. Here are the steps I followed: Removed HDMI cable Removed export DISPLAY=:0.0 from .bashrc using sudo nano ~/.bashrc Installed xming X server In PuTTY, I changed SSH setting -> X11 -> Enable X11 Forwarding and on windows side set display for CMD, I followed following steps from this guide set DISPLAY=127.0.0.1:0.0 ssh -Y <your_user_id> @ <server_address> Thanks for the support!

OAK-D CM4

erik

Hi NickNikzad ,
Due to how the device is designed (VPU connected directly to CM4), it's not possible to connect to the VPU from your computer. So you always need to connect to the CM4 to access VPU, just like having RPi + OAK, you'd need to connect to RPi and then connect to OAK from RPi.

NickNikzad

erik Thanks for your response. How about the OAK-D CM4 PoE camera model? Does it have a similar design and limitation in terms of the direct connection between VPU and CM4?

erik

Hi NickNikzad , yes, the same applies. So you have to SSH into the CM4 and then access the VPU. See here: https://docs.luxonis.com/projects/hardware/en/latest/pages/DM2097.html#poe-for-rpi-not-oak

NickNikzad

Thanks erik

AnshumanFauzdar

erik when I ssh into CM4 using -x tag and try to run any examples it gives opencv related errors.

erik

AnshumanFauzdar did you reflash the OS on the CM4? If so, it seems some libraries weren't correctly installed.

AnshumanFauzdar

erik This example is working fine on CM4 itself, when I SSH through windows OS it shows the errors as mentioned in screenshot.

erik

AnshumanFauzdar Does opencv work correctly (the imshow part) on your windows?

AnshumanFauzdar

erik Yes on windows, opencv works correctly. I tried imshow example:

Error is this:

jakaskerl

Hi AnshumanFauzdar
Not sure about Windows, but at least on MacOS the x11 is enabled using -X and not -x.

Thanks,
Jaka

AnshumanFauzdar

jakaskerl Thanks for the suggestion but still with -X I am facing same issue.

jakaskerl

Hi AnshumanFauzdar
I see, GTK backend issue is usually related to x11, but might be a bad display mapping as well, not sure for your specific case. Could you please check opencv/opencv18461 if any solution works for you?

Thanks,
Jaka

AnshumanFauzdar

jakaskerl Hey, I solved the issue by following the instructions on the issue. I edited the .bashrc and added the following in the last line export DISPLAY=:0.0.

But I want the GUIs to run on my windows, the demo is running on the raspberry pi GUI instead of launching on the windows side.

jakaskerl

Hi AnshumanFauzdar
What about using putty ? To my knowledge it should support x11 forwarding (there should be a checkbox to enable it), while the regular command prompt might not support it directly.

Thanks,
Jaka

AnshumanFauzdar

jakaskerl I tried putty and also ran Xming server on windows to enable X11 forwarding but still there is no GUI on putty or cmd.

jakaskerl

Hi AnshumanFauzdar
I'm not sure the GUI is going to work with X11 forwarding then. Could you try with a simple example (like rgb_preview) to check if standard CV frames go through? If this works, then I guess the forwarding does not support GUI.

Thanks,
Jaka

AnshumanFauzdar

jakaskerl I tried the examples, its executing on the pi itself and there is no GUI forwarding.

jakaskerl

Hi AnshumanFauzdar
I'm a bit confused as to what you are really doing here. I don't think you shoud VNC into the pi if you wish to forward the display.
I think that since adding the export DISPLAY=:0.0. you are telling the scripts to use PI as the display, so when you also VNC, the x11 won't work properly.

Could you try maybe disabling the DISPLAY, exiting the VNC and running the example (rgb_preview) with -X?

Thanks,
Jaka

AnshumanFauzdar

jakaskerl should I remove the export display and also remove the HDMI cable and only ssh headless?

AnshumanFauzdar

jakaskerl Thanks @jakaskerl now it is working completely on headless configuration. Here are the steps I followed:

Removed HDMI cable
Removed export DISPLAY=:0.0from .bashrc usingsudo nano ~/.bashrc
Installed xming X server
In PuTTY, I changed SSH setting -> X11 -> Enable X11 Forwarding

and on windows side set display for CMD, I followed following steps from this guide

set DISPLAY=127.0.0.1:0.0
ssh-Y<your_user_id>@<server_address>

Thanks for the support!