Photonvision - Network Tables error message

Technical PhotonVision
,
1

We have the latest version of PhotonVison running on a Raspberry Pi.
Running Java, VS Code, standard set of tools.
Loaded the PhotonVision libraries

Everything is working, we can see the video and target acquisition on the web interface

Using the Code example, Aiming at a Target

Our camera name is “PhotonCamera01”
No NetworkTables server running.

PhotonCamera camera = new PhotonCamera(“PhotonCamera01”);

Outputting to the SmartDashboard “hasTargets”, pitch, & yaw.

Running the drive station we see the following message

Cannot find networktables at /photonvision/PhotonCamera01

hasTargets = True
Pitch = Value jumps around
Yaw = 0, even when we move the ball.

Any ideas?

All help is appreciated

Coach: Mark Tayler
Team # 4361

2

Hi!
Could you do the following:

  1. Post a link to your code (if possible)
  2. Send a zip file of your settings (this can be done in the settings tab)

This will help us debug the issue, usually this is caused by a version mismatch somewhere or a code error.

3

The code I am trying is straight out of the Code Examples of PhotonVision

Find attached our settings
photonvision-settings.zip (183.4 KB)

4

The exact error message we are seeing is:
ERROR 1 photonVision coprocessor at path /photonvision/RoxCam2021-4361 not found on NetworkTables!
oarg.photonvision.PhotonCamera.verifyVersion(PhotonCamera.java:213)

5

That error says that the RIO can’t communicate with the coprocessor over NT. We’ve removed our Photon-running LL from the robot and we see that error all the time.

I see two options:

  • the coprocessor isn’t on the robot network
  • the name configured in the coprocessor isn’t the one expected by the code.

I’d use Shuffleboard/OutlineViewer/Glass with tree-view of all NT entries to check whether the DS laptop sees the coprocessor and under what name.

6

Hi! Sorry for being so slow to get back to you.

FIrst, I would look at what @Starlight220 said and follow those steps.

Next, you have another issue, a version mismatch between your PhotonLib vendor dependency judging from this code

On your coprocessor, you are running some dev version of PhotonVision according to the logs.

To fix this, change the 2021.1.2 in your vendordep to 2021.1.7 you have now and download the 2021.1.7 release. . You might notice that there is a 2021.1.8 release out, but stick with 2021.1.7 for now because there are some minor versioning issues with it at the moment.

If you have any issues after this, please let us know,

7

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