XBee series 2, point-to-point, do I need a coordinator

Hello there!
I am doing a little R&D in the area of home automation, with some iPhone control apps. I am having some difficulty with what I thought would be the simplest part - XBee to XBee. So, over to the experts :slight_smile:

I have 2 XBee modems, (Series 2), one in an XBee shield, attached to an Arduino, and the other in a (Sparkfun) USB Explorer.

Based on my readings on the Net, I used X-CTU (Admitedly under Vista) to configure these, but I had a lot of problems getting it to work reliably, so I have switched to using a simple terminal emulator.

Now, the real question. I am reading conflicting reports on the Net about Series 2 devices. One says that I definitely need a Coordinator to enable the 2 devices to communicate, and so will need to flash one of the devices with new firmware.

Another says that the firmware I have (1220, model XB24-B) should be able to do point-to-point, between two Router/End Device XBees. (The product manual does refer to “Point-to-Point”, but all examples relate to a full ZigBee PAN, with a coordinator. But some folk say that I can set a NodeID on each, and then set a “Destination Node Id” one each to point at each other.

Can anyone help?

Con, from (unusually) very sunny Ireland.

The easiest way is to set one up as a coordinator and the other as and end device or router. The only other option to get away from the coordinator problem is use the series 1 Xbees.

Wow, thanks for the rapid reply! That sounds sensible. I don’t suppose you have a reliable source of information on HowTo flash the XBee module? If I Use X-CTU, will it work with the X-Bee Shield (with PIC removed) or with the USB Explorer?

And if the answer is “go but the supported development kit”, then no worries, I understand :slight_smile:



I am not familiar with the Xbee Shield but if you are able to do a “read” within the modem configuration tab of X-CTU then you should be able to load new firmware onto the xbee.

In order to flash firmware on the XBee modules, you must have the following minimum pin connections. VCC, GND, DIN, DOUT, DTR and RTS.

As far as your original question is concerned, You must have a coordinator to establish a PAN, once the network is formed, then the coordinator could be removed and 2 routers could be set to communicate Point to Point.

One other suggestion. Since you need to flash one module to be a coordinator anyway, I suggest that you go ahead and upgrade all the modules to the latest ZB firmware (2x41).
This can be done by selecting either XB24-ZB or XBP24-ZB as appropriate from the modem list on the modem configuration page of X-CTU, then select the appropriate function set and version. check the “always update fuirmware” checkbox and then click “Write”. If your interface board has the minimum pin connection the firmware will be flashed to the module.