There are about half a dozen different XBee modems. It's a good idea to at least review the differences between them so that you can make sure that you have the right power, range and network compatibility for your project.
For the examples on the site, I use the XBee 802.15.4 modules. These are low cost ($20), reasonably low power and are the most popular XBees used by hobbyists for simple wireless communication.
There are half a dozen 'families' of XBee & it's important to know the differences.
|Name||Frequency||Network type||Max Range (Pro)||Notes||Convertible to...||Distributors, antenna type|
|XBee 802.15.4||2.4GHz||point-to-multipoint||300' (1 mile)||most popular, cheap||XBee DigiMesh 2.4||
Digikey (Wire $19), Digikey (Chip $23)
Mouser (Wire $20), Mouser (Chip $19)
|XBee DigiMesh 2.4||2.4GHz||mesh||300' (1 mile)||XBee 802.15.4|
|XBee Pro 900||900 MHz||point-to-multipoint||6 miles||XBee DigiMesh 900|
|XBee DigiMesh Pro 900||
||mesh||6 miles||XBee 900|
|XBee XSC Pro||900 MHz||both||15 miles||long range|
"Series 2" Pro
|2.4 GHz||mesh||ZigBee||XBee ZNet||
|2.4 GHz||mesh||400' (1 mile)||ZigBee||XBee ZNet||
The XBee 900 and XBee DigiMesh 900 operate at 900 MHz and so they cannot communicate with the 2.4 GHz frequency XBees!
The DigiMesh & ZNet 2.5 modules are preconfigured for mesh networking, not point-to-point or point-to-multipoint connectivity
The XBee 802.15.4 operate at 2.4 GHz but are not compatible with the ZNet/ZB/"series 2" modules!
If you just want to wirelessly send data from one place to another chances are you'll be most happy with the low cost XBee 802.15.4
For some of the families, the module is available in both a low-power and Pro version. The Pro version often has an extra amplifier for longer range. However this means that the power required to run the modules is also a lot higher! The adapter can be outfitted with either kind of module but research and testing is often necessary to determine which one is suitable for your needs. Some Pro modules use a lot of power, The ones that need 265mA should work fine but if your version/antenna needs 300mA, you may need a better power supply to power it.
Note: Some of the Pro models (XBee Pro S3 and S3B) have a slightly different pinout that requires a modification to the adapter. In particular, pin 6 which is the RSSI indicator for most XBEE modules is used as a configuration signal on these models. To use with the S3 or S3B models, you will need to remove the red RSSI indicator LED.
There are three different antenna-options available for the XBee radios:
The chip and wire antennas are already on the board and don't require any work on your end. The UFL and RP-SMA options are just connectors, they require an antenna tuned to the correct frequency and with the proper connector in order to function!
Unless you are doing something that requires a special antenna for directed or high power transmission, the chip or wire antenna options will be just fine.