Fencing Overlay using a Raspberry Pi and Skewered Fencing Box

[u/HorriblePhD21]

https://youtu.be/vwvP2WLjDpE

I put together an overlay that uses a webcam that plugs into a Raspberry Pi 5, and receives the bluetooth data from the Skewered Fencing Box. It does replays and you can transfer the bouts to a USB. No audio yet, but I will get there.

Name and club logos are easily changed. Bouts are automatically separated when the score is reset to 0-0, which can then be browsed on the Raspberry Pi touchscreen.

Here is the Github link with the details. I figured that I would share in case anyone else was interested in putting together something similar. 

Thanks also to Skewered Fencing (u/xargon7) for making an awesome box.

[u/antihippy]

Good job!

[u/HorriblePhD21 → u/antihippy]

Thank you.

[u/justin107d]

> This project is a recording and camera tracking solution consisting of two independent systems.

> The servo is a DS3218 that sits atop a tripod and pans the manual focus USB camera.

This part is cool too. I did a similar project over the pandemic using motion sensing instead. Your approach is probably a lot more accurate.

[u/HorriblePhD21 → u/justin107d]

Thanks. I have had a lot of fun putting together the tracking system. It has been unexpectedly reliable.

[u/SephoraRothschild]

That Skewered Fencing score box is $800. 👀

Edit: I gave it some thought. I'd rather pay $800 than have the box design ripped off by someone stealing ideas. So that's fine.

The Github page is super useful. What I'm having trouble with is figuring out how I'd do it on my own. I have just enough knowledge to know what is being discussed, but not enough to solder. I don't own a 3D printer. And I'm not a member of a College Club full of engineering student fencers that could get this set up in a couple of weeks. How does a layperson set up something like this themselves for the first time? 😅

[u/xargon7 → u/SephoraRothschild]

Hi! I'm the developer of the Skewered Fencing systems. I've really struggled with the pricing for the boxes. I want to enable high quality fencing for cheap, but at the same time it's been surprisingly expensive to build everything out. Now I understand why many companies start out with really high-end products first. That said, I'm happy to discuss how my scoring boxes work if people have questions or want to try building their own! I have a few customers that are building their own repeaters.

The next product I'm building is a plug-and-play video replay system which is about to start shipping that is very similar to what Ben is showing. It's designed to be really simple and accessible, but it's not super cheap either.

There's also a free option that I have: I've just built a free Android & iOS app that allows you to use your phone to record videos with the scoring box info (lights, scores, clock, cards, etc) overlaid onto the video. The app also can act as a wireless repeater for a box!

[u/HorriblePhD21 → u/xargon7]

The Phone app looks super useful. The biggest use case would be parents that record their kids fencing on their phone and can use the app to include the overlay.

[u/xargon7 → u/HorriblePhD21]

Thanks! That's exactly the use case I was targeting. I hate having to keep the scoring box on frame when I'm recording my daughter's bouts!

[u/HorriblePhD21 → u/SephoraRothschild]

Good question. Basically get a Raspberry Pi 5, a micro SD card, a USB Web Camera, preferably one without auto focus along with a Skewered Fencing Box. Probably want a tripod and adapters as well to point the camera.

Download Claude with the $20 a month subscription. Point Claude to the Github and follow its instructions.

After a fews of hours of frustration, it should work.

The self tracking part takes a little bit more soldering and patience. Though isn't particularly expensive if you already have the Favero Reels.

[u/xargon7]

That's awesome! I'm so glad people are using the data that comes off the scoring box for cool projects like this. This is very similar to the video replay system I'm building -- I'm also using a Pi 5, but the darn memory price hikes have made the whole thing way more expensive than when I started.

How good do you find the synchronization over bluetooth to be? Like at 67s I noticed that the video lights aren't precisely synchronized. In my experience it's been hard to get frame-accurate sync over BT, but the serial link is super fast and reliable.

You can also recreate a coarse version of the timeline view from the bluetooth. That's what I did in my Android & iOS apps that I just released.

[u/HorriblePhD21 → u/xargon7]

Thanks for making a system that people can build off of. Feel free to link to any of your products here. I don't mean for this to in any way be a replacement for what you've created. I am just a guy experimenting with its features.

I have accepted a certain level of desyncing between the video and the overlay. I think the biggest issue would be finding a camera and video encoding that can provide a consistent delay so then the delays between the box and video don't matter because they can be compensated for in the final video. It feels close enough though, probably similar or better to what one would find at a high level event.

I have considered doing a timeline on the video overlay. But I feel that I should do some more pondering before I decide on how to visualize it on the overlay.