Bluetooth in stands and pit

As I’m sure we all know WiFi networks are not allowed at FRC events. But what about bluetooth? Do they get fussy about that? Based on my understanding a large amount of bluetooth traffic wouldn’t effect local WiFi performance. I am looking to set up a bluetooth network in the stands for my teams scouting system and wanted to check with CD on this before I start going in too deep.

You’ll find all the non-robot event restrictions on wireless communication in the event manual, have you read through that yet?

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I have not. My guess I could find it i first’s website. I’ll have to read it

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I had it up for something unrelated; here’s the link to it for yourself and anyone else who might be interested: https://www.firstinspires.org/sites/default/files/uploads/frc/EventRulesManual.pdf. You’re looking for page 6.

It’s actually not entirely clear to me here. E301 line specifically references 802.11. Bluetooth isn’t 802.11, it’s 802.15.1, but Bluetooth does operate on the 2.4GHZ frequency and can cause interference in certain cases, but I don’t have anything empirical on my own or otherwise from Google, so I’m not sure where that should leave us.

6328 does use a Bluetooth PAN for their scouting system. I would assume if they’ve integrated Bluetooth into their scouting app then it’s allowed but I’m not 100% sure if there are restrictions put in place that they’ve worked around.

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Our (6328’s) scouting system actually uses Bluetooth serial rather than PAN. The “documentation” on the repository is currently very outdated — we’re doing a bunch of work on our scouting system during the offseason, so that’s one of many things that we hope to significantly improve. We switched from PAN to serial early on because of reliability issues. We’ve never had any issues using Bluetooth at events, though we would of course be accommodating if necessary. This issue was also addressed in a Q&A in 2020.

A word of warning; it definitely takes some significant development effort to make Bluetooth work reliably. We went through three major protocol iterations (tested at various offseasons) before we were satisfied with the reliability and willing to use it in season. If you get past that hurdle, we’ve found the realtime (and offline) communication to be incredibly useful for monitoring devices, updating schedules, uploading automatically, etc.

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I’m not sure you’re allowed to use Bluetooth in the stands even…

Doesn’t make much sense now a days because my Apple Watch and AirPods use Bluetooth, and I do not turn those off at competitions

There is nothing preventing Bluetooth communication at an event:

E301. *No wireless communication. Teams may not set up their own 802.11a/b/g/n/ac/ax (2.4GHz or 5GHz) wireless communication (e.g. access points or ad-hoc networks) in the venue.

Bluetooth (IEEE 802.15) is not 802.11, so it is allowed.

We have used Bluetooth in the past for a scouting app and never had any trouble.

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I was looking at your scouting app and are you using like a website but using Bluetooth instead of Wi-Fi?

Assuming Bluetooth is OK (I’m not in a position to say, so I’m adding this qualifier just in case), you can set up a PC server for your website and then do something known as reverse Bluetooth tethering: https://www.howtogeek.com/214375/how-to-reverse-tether-an-android-smartphone-or-tablet-to-your-pc/.

Further, if that PC has a connection to the Internet (wired or by being tethered to a cell phone, possibly even wirelessly via Bluetooth), the other devices should be able to share that connection.

There’s both a web and app version of Advantage Scout. The web version is primarily for development, but the same code base (mostly) is packaged into an Android app using Cordova. The app does not require a network connection to the server to function — data is cached locally if required.

We use a Cordova plugin for Bluetooth serial. Unlike with “reverse tethering” (which is still Bluetooth PAN), we don’t get a full network connection through Bluetooth serial — you can’t connect to the server laptop through a browser. We made the switch from serial to PAN because we couldn’t get it to work reliably for hours even under ideal circumstances (e.g. a MacBook and iPhone in close proximity, and Android is even worse).

The current code base is a bit of a mess, and some code is spread haphazardly between sub folders or duplicated unnecessarily between the web and app. All of that should be much better after the major rework we’re doing this off-season.

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