You can switch between 4 clients, but you cannot communicate simultaneously, that's how I've always understood it to be.

- Xander

I would have gotten some a long time ago, if not for the fact that I'm on a 13-year olds allowance, and I'd need to spend at least $100 to get a pair of them with radios. I'd love to have fast, reliable, wireless communication. Especially since I'm now interested in building boats. I don't want the BT connection to suddenly drop, leaving my exspensive NXT stuff stranded in the middle of the lake.



Yes, your right, but the thing is they haven't implemented a connection to have a master with multiple slaves. Here's my test code:

Master NXT:

Slave NXT code. There are supposed to be two slaves:

Now, when I run this code, the Master connects to the two Slaves, but only the last one it connected to receives commands.

BT in LeJOS? It's my understanding that you simply set up a connection, and you can pretty much directly control the other NXT's sensors and motors without manually exchanging messages, as well as normal messaging.



Yeah, which is why the NXTBees would be very useful to me, if only I had enough $$$ to get them

EDIT: I forgot to mention what the program does. It was just a test to see if multi-NXT BT worked, and it would count up time in tenths of a second.

Well, like I said, it looks like they at least intended to have in place what the hardware supports, however badly the hardware supports it. Whether or not it works, I have not tried it (for more than 1 master (the PC), 1 slave(the NXT) as I mentioned.

I will say that the firmware implementation can be a bit confusing at best. I know I had to modify the mindsqualls library some. For example, when a master says 'read message' it gets a 'write message', as a reply. since the command echo does not equal, it (the original mindsqualls library) throws an exception.

LeJOS does have a way to send direct commands, aka LCP. But in reality it would not be much trouble to do them with raw bluetooth from robotc code as well. I think you would still have the inability to have multiple simultaneous connections. I may be wrong, but do some checking first before you commit to that (LeJOS) path for that reason. They are by no means, realtime. Don't expect to do a sensor sweep and get the same data rate you would from local code (been there, done that). Or even try to remotely control an accurate motor. I suspect you quickly will fall back to the messaging scheme, that in theory should also work in robotc.

Since 'only works with 2' seems to be common knowledge, I was just wondering if anyone had ever filed a problem report and gotten a response?

The big interest for me, is that robotc debugging, which I depend on, takes over the buetooth stream. So if I also want to do communications, I'll need the xbee or something else. I plan on going down that road eventually. But until anyone comes even close to robotc as far as debugging, ill stick with it. I notice that as a difference between software guys and hardware guys, hardware guys seem to be able to get along fine without debugging. (guys and gals of course, no discrimination intended).

Mike

I use debugging a LOT when writing my drivers for the hardware I am testing

- Xander