Mindboards

Hey all again,

I am planning to use about 12..15 NXT's, all connected with about 5 laptops, over bluetooth. I am a bit concerned about how stable the connections can be. Do you think there is any problem, conflicts between communications or, for instance, problems when running other kind of bluetooth devices near the NXTs and PCs?

Well, remembering the Monster Chess project, I would say that it's OK, but...?

Cheers,
Ricardo Oliveira

I think a computer can only be connected to one NXT at a time. In the case of the monster chess game, I think Steve had it set up to connect and disconnect when needed, automatically. BT uses the 2.4 GHz band, but that band has many variations of frequencies and protocols. I don't think that BT really ever has a problem caused by other BT signals.

Bluetooth, WiFi and other similar signals are whatch-a-call frequency hopping, meaning that every little package of information gets transmitted at a different frequency. This reduces interference, not completely but somewhat. You should be fine having 10, maybe 15 NXTs going all at the same time, it's just going to take a lot longer to connect and maybe 20-30% longer to send data.

A PC can connect with seven bluetooth devices at a time. That's part of the reason we had to make and break connections while moves were being made.

However, we sometimes take it to places where there are lots of people with cell-phones. It sometimes seems slower making the connections, but I couldn't tell you how much.

Steve

Many thanks to all! That's precious information.

Interesting to know that the bluetooth protocol has the limitation of 7 devices connected at a time. I thought that was not a constraint. But for me it's OK!

Cheers,
Ricardo