- Mon Dec 18, 2006 8:08 pm
#23875
I have used the MaxStream XBee and other vendors' modules. The XBees and XBeePro (be sure to buy the XBeePro if you can go the extra $ - much more range).
The XBee's can take a firmware download of either (a) plain old IEEE 802.15.4 where you address the destination node by its MAC address and there can be no meshing or relays; (b) load the ZigBee firmware where the mesh routing comes into play. Use (a) if your needs are simple point to point.
In either case you communicated with the module using serial data at the default rate of 9600Baud, or any rate up to 115000 if you reconfigure it. You can control it (say, set the destination MAC or NWK (ZigBee) address, using either AT commands or a binary mode. The AT commands are tricky, as you remember if you ever wrote modem control code: you send +++, wait just the right amount of time, then an AT command. The binary mode requires a lot more code but it's easier once it's done.
If your from/to addressing is static, say A talking with B, and vice versa, then you set the MAC addresses once using a dumb terminal program and forget it. From then, A and B exchange data on their serial ports- that is, it's a transparent serial-to-wireless-to-serial bridge, and bi-directional, with internal buffering and RTS/CTS flow control.
Pretty good for $20 @ 1ea (XBee) or $35 or so if I recall correctly, for the XBeePro.
There are at least 8 other modules on the market. I have a few of these. MaxStream is the best for the hobbyist. Sold by Digikey and Mouser.
I wish SFE would diversify - they have only the Jennic which is an odd-ball one.