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[Reply #15 on:]

Sounds like pretty much a line-of-sight situation? About how far? I may be overly optimistic and I don't know what I don't know, but I'd be surprised if there was a lot of trouble making it work.

Me too.

I'm not familiar with the Nordic technology, but perhaps there is something similar available.

Ranging testing can easily be done between two arduinos with two RF modules.

[Reply #16 on:]

I'd go with XBee.

With the amount of 2.4G around here I'm amazed at how well they work!
Have a look at my Rover 5 video, both the XBee and the camera are on 2.4G.
Neither minds a bit.
My analogue 2.4G video sender/receiver is totally swamped, I had to shut down all the Phones, cell and cordless, AP's, Laptops, Netbooks to get a picture.
So to use the analogue video link on my rover I bought a pair of 900Mhz XBee modules.

Ya, those 2.4GHz video transmitters are notorious for swamping the 2.4 spectrum. Its why a lot of people don't like them. They tend to be rather indiscriminately hostile to any 2.4GHz device in the general area. They frequently make all 2.4Ghz other users in the area rather hostile to those who use them. Even been known to fracture relationships with neighbors. They cause problems for WIFI, bluetooth, baby monitors, and wireless phones.

Honestly, for anyone wanting to do video, I encourage you to do it on a different frequency than 2.4Ghz.

[Reply #17 on:]

I hadn't noticed the other 2.4G devices being affected.
My analogue unit uses AirWave modules, they seem pretty civilised around other devices.
The data rates with Bluetooth, WiFi and XBee seem fine, the digital video link as well.
But I wouldn't want to be flying FPV with this lot going!

[Reply #18 on:]

One of these days I will go back and make the XBees my be-atch.  They're going to work whether they want to or not.

What kind of XBees are they? Series 1 models are trivial simple to make talk to each other. Fire up X-CTU, change 3 parameters and write the changes, and they work. Series 2 are not that much more difficult.

Specifically, they are XBee-PRO ZB S2B.

I can get them to work in X-CTU, I can talk to them and all.  Even burned a new firmware.  However, getting them to talk to one another still eludes me.  They've been sitting on a shelf for the better part of the last 12 months now ...  The project for which they were originally intended went on with Nordic modules instead, so these guys took a backseat.  But, I would love to revive them and get them to work.

[Reply #19 on:]

Here's another thought: what if I make the individual pieces wireless and add my own router to act as a closed hot spot?  I have to believe that if there's a router sitting right on stage, its signal will be more powerful than the one that's right outside the auditorium.  Especially with the doors closed.  If I make it simply act as a hot spot and DHCP server, then each piece that needs it can connect directly to it and be able to talk to the rest of that network.  It will not be communicating with anything else, not the other (building) wireless, or whatever wireless devices around.  Hell, for that matter, I could use my phone as a hotspot.

Of course that would mean adding wireless capability to everything which in the end may or may not be more expensive, I haven't figured that part out yet.  But, it would also give me the ability to run everything wired as well (providing I add ethernet capability of course.)  Same IP protocol.

Ah, the joys of dreaming ...

[Reply #20 on:]

You can get wifi modules that plug into XBee shields, like this one http://www.sparkfun.com/products/10822. Digi also makes one that supports 802.11n and an SPI interface for higher data throughput.