Limelight on a Romi

[Mr.R_2]

Excellent. Yes. The Firewall is messy. It is a bit worse with the Romi than the full-sized bot because the full-size would typically either work or not. The Firewall probably blocks all communication. But since the Romi WebSockets work out of the box, there is a bit more room for it to work until you need Romi-generated network tables.

[BlueEpiphone]

I’m seriously thinking about contributing to the PhotonVision docs on Romi installation to add the info I’ve gleaned from CD to make this work. The last few steps regarding making the filesystems writable and doing a more thorough modification to the start scripts to get the software running are missing. Also, just a line about the firewall being an issue. Maybe the bit about setting Shuffleboard to localhost, but that might belong on WPILib docs. Unless someone else beats me to it, or maybe there’s already updates that haven’t made it to the latest release?

If anyone on the WPILibPi & Romi projects read this, I wonder if it would be possible to install PhotonVision without needing to make the boot and root filesystems writable? Perhaps by allowing a separate partition for applications under /opt? Currently, the WPILibPi partitions the whole card on boot. The main benefit is that it might not be necessary to shutdown the PI manually, though there is value in teaching kids a bit of Linux as well It may just be the cost of doing something more advanced with the Romi.

[mdurrani834]

@BlueEpiphone

I’m seriously thinking about contributing to the PhotonVision docs on Romi installation to add the info I’ve gleaned from CD to make this work. The last few steps regarding making the filesystems writable and doing a more thorough modification to the start scripts to get the software running are missing. Also, just a line about the firewall being an issue. Maybe the bit about setting Shuffleboard to localhost, but that might belong on WPILib docs. Unless someone else beats me to it, or maybe there’s already updates that haven’t made it to the latest release?

HI! I usually manage PhotonVision docs related stuff. If you would be willing to contribute that information, we would really appreciate it. You can find our repo here: GitHub - PhotonVision/photonvision-docs: Docs for PhotonVision, a free open-source vision processing software for FRC teams. and contributing instructions here: Contributing to PhotonVision Documentation - PhotonVision Docs. Otherwise, I’ll get around to it soon (may take a while because my Romi is at the team workspace atm) and will let you know once it is live.

Thanks for letting us know!

[Mr.R_2]

I like the idea of modifying the docs. I almost submitted a PR when we figured it out but held back as this is a dofferent paradigm than the version that was up there. That version replaces the WPILib camera server process. This one uses it to launch Photon. So, I did not know which would be best. I wonder if it would be good to have both versions.

[Peter_Johnson]

@BlueEpiphone

If anyone on the WPILibPi & Romi projects read this, I wonder if it would be possible to install PhotonVision without needing to make the boot and root filesystems writable? Perhaps by allowing a separate partition for applications under /opt?

There are a lot of different opinions on the Internet as to how frequent an occurrence SD card corruption is with the Raspberry Pi, but the one thing everyone seems to agree on is that making all the filesystems read-only prevents this issue. Given that FRC robot-powered rPis are frequently turned off and on at random (and the Romi is too), I’m not liking the risk of changing this default. That being said, I can see the argument for having a separate filesystem configured (still read-only by default) that could be made read/write at presumably lower risk than the root filesystem.

Note that even with this change, PhotonVision will still need to limit writing to only those locations, and I don’t know where it writes to today–if an /opt was created, could PhotonVision be configured to write there?