Limelight 2+ with Photonvision doesn't connect?

We have unsuccessfully been trying to use our limelight 2+ with code for april tag detection & more. As recently as two weeks ago, everything ran fine. Now, since the last update, we have been unable to use limelight with photonvision. https://photonvision.local/ also will not connect. Everything is imaged & up to date, team number is set, we can see the limelight stream using limelight finder, just won’t connect to photonvision. We’ve seen some threads that say we need a network switch on the radio, is this the case?

We pulled our 2022.2.1 Image (I think, whatever the latest stable one is) due to networking issues on the Limelight. This is noted in the release notes. Some devices work just fine, some devices don’t. I recommend rolling back to your last working image or trying this image Bump Photon to 2023.2.1 · PhotonVision/photon-pi-gen@3977ac3 · GitHub

In general, you want a network switch, but you should be able to at least get it working without one.

Thank you, we will try that later tonight. Would you recommend that we use our driver station laptop for the photonvision server, or a add in a raspberry pi on the robot itself? We plan to implement two cameras, one of them being the previously mentioned limelight, and just another USB camera.

At competitions there is a 4 Mbps wi-fi limitation and we try to keep it below 3 Mbps to minimize jerky performance. Sending that extra camera stream off the robot to the DS will likely use way too much bandwidth. Keep the targeting system completely on the robot and you can use high resolution and nearly instant results for your Robot program.

Sorry I have to edit to admit I’m making some assumptions. Are you talking about using the LL hardware with or without LL software? Are you thinking of using another IP camera? What are you plugging your cameras into if the processing is not on the robot but on the DS?

To be honest, this is personally our first year programming on the team. We use limelights every year, but the lead programmers graduated last year, so we are inexperienced with it. We are using photonvision with the limelight, so we aren’t using the limelight software, correct? We plan on using a Logitech C920x Webcam, I’m not sure if that’s the exact model, but I believe it is. We haven’t set that up yet, but from what we’ve seen online, we will need to connect that to a Raspberry Pi, right? Also, since the limelight is considered a coprocessor, we don’t need to connect it to anything besides the PDB & radio, right?

If these are still merely never tested plans then I suggest experimenting ASAP. I’m no expert at LL or PhotonVision but have used both and our own custom software for years. I’ll try to answer but do try out your vision soon.

Yes, if you load PhotonVision software instead of the LL software on the LL hardware. Either software works well - pick the features best for you - so I don’t have to tell you which one my team is leaning toward but haven’t finalized.

Be careful of any Logitech on any of the Linux boxes. All my use of them had them usually initially fail by displaying only speckles and it required unplugging and re-plugging the camera to get them to work. You can’t be doing that during a match! I don’t (usually) argue with success so if yours work - great.

I never got Logitech to work reliably on any RPi - WPILibPi, my own program, LL, PhotonVision. If anyone knows the secret to success, I’m all ears! You have to try this to see what works for you.

Largely true, but…

  • I wonder what else it could be considered but I guess that doesn’t matter.
  • From my teams experience (school of hard-knocks education or we lost some matches not doing this) we believe the best practice for reliable connection is that espoused by many great CD contributors as “use a switch.”

Plug all Ethernets into a switch (roboRIO, radio, co-processors, etc.) If you are not familiar with POE be aware your switch probably will smoke if you put the power side of cable into it (YMMV). (You could ask me how bad that smells as I happen to know the answer to that question.) And don’t mix up the radio POE if you use it (you have a couple of choices on that and the Rev power injector is best for us) and the LL POE if you power it that way (we do and like the ease and reliability.

Also pay attention to what the power spec is for the switch. We went with the BrainBox often (but not always) recommended on CD. It, too, plugs into your version of a PDP (I presume that’s what you meant by PDB) without any other power regulating devices needed.