What is xBee.? How does it operate?

[old97]

Thank you to Ozirock for your warm welcome to the intriguing world of die cast conversion .
My first forum question being a Futaba and Spektrum RC system user is "what is the xBee system and how does it work" , is there something on the internet which would give me a basic understanding of installation, circuits etc.  This is an area I'm unfamiliar with.
Many thanks
Barrie

[RC Tractor Guy]

Well an XBee is an RF module, so basically all the RF circuitry, antenna matching circuitry and antenna have been designed into an easy to use module. Similar to the RC receiver you would be used to but capable of much more, the standard normal RC system is bound by servo signal whereas the XBee is effectively a wireless micro controller which sends serial data and is intended for industrial application.

Now I don't scratch the surface of its possibilities with these tractors, I use the series 1 modules because they come ready to go out of the box. Two series 1 XBee modules out of the box will form a wireless serial link no setting up required but if you do want to adjust the setting you need something like an FTDI cable but you'll need one of those to program an Arduino pro mini anyway. I use them to form a serial link between an arduino in the tractor and an arduino in the controller. This means I can send information both ways to do whatever I like and as they operate at 2.45 GHz the data rates can be very fast too although I have stayed at the lower rates as I haven't needed to go over a baud rate of 9600. That is 9600 bits per second which I think is more than fast enough for an RC tractor

The downside is they are pretty expensive, each module is over €20 or €25 here depending on the antenna you choose. I would advise the whip antenna as it would have a more doughnut shaped radiation pattern around the antenna where chip antennas usually has poor efficiency and the pcb antenna would probably transmit most energy away from the ground plane so mostly focused in one direction. That said you'll be so close to your tractor it probably wont really make any difference which you choose.

Now that I have a few tractors working I'm looking for a cheaper alternative and I've order three of these guys from IC station. They are around €5 each so a little easier on the wallet but I'll have to test if they are a good replacement. It will depend on how easy they are to set up and how good the signal is from the PCB antennas. I'll probably receive them in a week or two and then I'll test them out and do a video on them. If I was you I'd work on the arduino end of things first you need something like an FTDI cable to program your Arduino pro mini and you can use it as a wired connection to test your tractor which is what I always do. By the time you have that all figured out I should know better on the cheaper modules.

If you decide you want to use some other module you find other than an XBee or something else we should still be able to help you get it working. There is a limited number of communication protocols they can use I just choose the serial (UART) communication because it is easy and uses only two wires. You should also note that RF modules usually operate at 3.3 volts so you need to possibly run your Arduino at 3.3 volts too or use a level converter. Here is a link where a guy talks about XBees and shows different wiring configurations.

[old97]

Very many thanks for such a comprehensive reply. This all sounds interesting and I will gen up on it. It certainly seems the way to go. Thanks again for your help.
Barrie

[RC Tractor Guy]

Its no problem, I'm glad to see the forum growing a bit and I'm more than happy to answer questions (as best I can) when I have time.