Robots sharing information

[Monochron]

I was wondering about this a while ago and I don't even think you would need to know the IP of partner robots. Your protocol could start off with broadcast messages and each robot could start an election process or something similar to select a master. Unless I am missing the limitations of how the VLANs are setup it sounds like a really interesting case study for students to get some ad-hoc network programming done.

Ideally someone could put out a single API that teams could hook into to establish communications. Then sending could be as simple as calling the API and letting it take care of the networking.

[Jon Stratis]

Check out the FMS whitepaper:
http://www.usfirst.org/sites/default...Paper_RevA.pdf

It seems to indicate that communication between VLANs is not possible, although it doesn't go into sufficient technical detail to explain why.

The FRC competition field is configured such that each team has its own virtual local area network (VLAN) within which all data is passed. The characteristics of a VLAN ensure that the command packets from one team’s DS do not cause a response on another team’s robot. These VLANs exist on both the wired and wireless side of the playing field’s network; this is why for example, it’s necessary for a team in Blue Player Station #1 to connect their DS into the corresponding cable for that station. On the wireless side of the network, the VLANs are configured in the field access point by broadcasting an individual network (SSID) for each of the six teams on the field, each with its own encryption passkey. These VLANs are configured prior to the start of each match so that only the six teams assigned in FMS may operate on the field.

[techhelpbb]

Let me propose something else to achieve this result...

In previous years I asked in the official questions if a team was allowed to place a light source in the driver's station area anywhere for their alliance. In other words...if you are in 1,2 or 3...I asked if we could put say a flashlight in our other alliance member's windows. The answer was yes at the time as long as they agree and it does not require a power source or extra interconnecting cables.

So that would sort of indicate that there is a chance that FIRST would allow you to send data between robots or driver's stations using light. Maybe by modulating the low power laser we have in the past been allowed as well.

There are lots of ways to send data using light: modulation and encoding for example. You could take a picture of a QR code: there's a bunch of bytes and if you do that over and over there's a lot of bytes. You could watch an LED toggle between ON/OFF or change color. You could AM modulate a laser. You could use IrDA transceivers.

You could potentially exploit the fact that some cell phones have a camera that faces the user.
You could potentially use NFC.

So this is solvable without exploiting the field.
There is a way to actually communicate across the VLANs but it is a hack and very ungracious to your competitors.
So please - do not put yourselves or your team in the position to get in trouble with FIRST.

[FrankJ]

The Crios are on a different subnet from everything else. You would not be able to easily talk to other than your own even without the VLAN present. The competition FMS uses smart switches so DS computer only routes to the FMS computer & their robot. Without the smart switches the Driver Stations can see & talk to each other via ethernet.

[Tungrus]

FMS is secured, external access is not possible (as far as I know). Robot to Robot communication sounds interesting and great potential, however I am concerned with other robots taking up my bandwidth and other resources or the worst opponent rogue bot making our robot dance to their tune!