angelsix:
http://www.digi.com/technology/wireless/products.jsp
XBee® 802.15.4 Radio Modems
Very much liking the looks of this module. Will it have the ability to do some sort of pairing between module so they can be interchanged, for example 3 modules, and all can be implemented using a PIC chip or something so that by pressing a button module A and B pair, pressing another means module B and C pair etc… or can they be placed into a discovery mode?
The only reason I am looking at this option to start with instead of doing my own implementation of a wireless chip is the timescale I have for the project, so this would be brilliant if I could get it out-of-the-box working.
Read up on 802.15.4.
Beware difference between Digi’s XBee series 1 and series 2. The latter is mostly if you want the complexity and sophistication of meshing via ZigBee. Series 1 for simple star and fixed cluster tree, and the best for most hobby/robot scenarios: peer to peer direct, no PAN coordinator.
802.15.4 radios have source and destination addresses just like ethernet. And a broadcast address. And MAC layer ACKs like 802.11.
XBee series 1 comes with standard firmware from Digi to do serial port extension wirelessly, transparent. And automatic A/D and digital I/O via wireless, to n nodes, with no firmware development. Just uses Hayes Modem AT-like commands.
To be fair, there are many other 802.15.4 modules, ready to go, from Jennic, ST, OKI, Panasonic, et al. XBee is sold here and is very simple to use and has pin/socket rather than surface mount.
2.4GHz XBee PRO (higher power option) with the right antennas can go a mile. There’s a more costly 900MHz version (US 900MHz) that can go farther, though antenna gain = big antennas at 900MHz so net sum gain of lower freq is zip.
Now consider too graduating from the crude PIC bank switching kludge to Atmel AVR or brand x ARM7.
estudio mucho