Limelight on a Romi

Has anyone considered mounting a Limelight to a Romi chassis? I think an external battery pack to power it, ethernet to Pi, and mounted somehow (3d print something). Could this work to get programming students familiar with using the Limelight ahead of building robot? Is this integration even possible programmatically?


This experiment has been on my to-do list for a couple of weeks. It should be as easy as plugging the Limelight into the ethernet on the Pi and giving it power, assuming the WPILibPi image is configured to bridge ethernet to wifi.

“It should just work.”

It is not. We can look at adding this though.


Thanks Peter, that would be a huge help to our programming efforts. Forgive my lack of knowledge but is it difficult/time consuming to add that feature? Thanks for all you do.


Though i will add that we have found it useful to be able to tether the Romoi+Pi to the development computer using an ethernet cable (makes it possible to screen share in a zoom session without losing internet) so I hope the two use cases would be compatible.


Does that mean a Limelight could work tethered?

Given that the Raspberry Pi image used for Romi is the WPI Vision image, you can drop a Raspberry Pi camera & LED ring onto the Romi and use the WPI_Pi vision tools. The physics & hardware is very similar - yes, the UI isn’t quite as polished/easy-mode.

From the fact that tethering works… Peter, do you think they could put an unmanaged switch on the Romi and talk to both the limelight & PC?

This is the smallest gigabit switch we’ve found, and has survived FRC competitions for us. It’s still going to look huge on the Romi, and I don’t remember if it takes 12v or 5v…

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I find having a usb wifi adapter on the dev computer so you can have the robot and internet both connected helpful.


It occurs to me that it’s also possible to just connect the computer’s ethernet to the network/internet and use wifi for connecting to the robot, if a network drop is convenient.

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It’s a 5V product.
(I just bought the “Amazon Warehouse” version and didn’t get a power supply in this box, kinda annoyed and can’t tell yall what current it’s rated to draw yet)

Hi Peter! We just recently got our ROMI driving around and it has been awesome for the new team members. I came across this thread when we looked at adding a Limelight or GlowWorm to the ROMI. Do you know if there are any plans to incorporate similar platforms or what our best course of action should be to get one operational with the ROMI platform?

Hi! I’m not Peter but I do work with the PhotonVision team from time to time. If you already have a Gloworm running PhotonVision, we have documentation for installing it on a Romi: Installing PhotonVision on a Romi - PhotonVision Docs

If you already have a LimeLight (Gloworms are not for sale at the moment but should be back at a later date), you can follow this documentation to install PhotonVision on a Limelight Installing PhotonVision on a Limelight - PhotonVision Docs and then work from there. To my knowlege, Limelight has no docs on using it with Romi but I am sure it is possible if you don’t want to install PhotonVision on it.

If you have any other questions about PhotonVision or need help with using it, do not hesitate to reach out.


We have not used it with the team yet, but I have been using Photon with the Romi. It is really easy. The only caveate is that you need the pi to be writeable.

I built upon what others have done, but all I did was put the .jar in userspace then wrote a Python file that starts photon. I uploaded that as the python program, and it runs automatically. Even the pi camera (if you are careful with the cable) works sufficiently.

From there, programming photon is really similar to the limelight.

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Awesome! Thanks for the info. We will give it a try.

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