XBee modules are RF modules that are manufactured by Digi International. There are various XBee modules that we can use in our robots. One of the XBee modules is the XBee Series 1 that supports the IEEE 802.15.4 protocol. This module has features to address multi-point packets. For further information about the XBee Series 1, you can visit this site: https://www.digi.com/products/xbee-rf-solutions/2-4-ghz-modules/xbee-802-15-4.

XBee modules can be found in several online stores and even in your local stores. The following image is of the XBee Pro 60mW PCB Antenna - Series 1 that is available on SparkFun: https://www.sparkfun.com/products/11216. Another product model that can also be used is the XBee 1mW Trace Antenna - Series 1 (https://www.sparkfun.com/products/11215).

Basically, the XBee Series 1 supports point-to-point networks but we can configure it using DigiMesh firmware in order to work with a mesh network. I will explain how to configure the XBee Series 1 to use DigiMesh firmware in the next section.

Another option is you can buy the XBee DigiMesh and XBee S2C or the latest of XBee Series 2 module to work with mesh networks. For further information about the XBee DigiMesh, you can read https://www.digi.com/products/xbee-rf-solutions/2-4-ghz-modules/xbee-digimesh-2-4. Here is what the XBee S2C looks like:

These XBee modules have their own header pins so if we want to access these pins, we'll need an XBee shield or breakout. There are many XBee shields that fit your board. They are also available for use through PCs via XBee USB, for example, SparkFun XBee Explorer USB: https://www.sparkfun.com/products/11812. You can put an XBee module into this breakout. Then, you can connect it to your computer through a USB cable. You can see the SparkFun XBee Explorer USB here: