Zigbee Comms

Wireless Data for Argonaut

Copyright: Copyright 2007 Dean Hall. All rights reserved.
Author: Dean Hall
Revision: 2
Date: 2008/01/28


I would like a wireless data network for my mobile robots in order to provide telemetry data and robot coordination. I've considered 802.11, Bluetooth and Zigbee.

802.11 is a posibility given the availability of SDIO cards, but creating an SDIO driver would be a considerable task.

Bluetooth suffers from feature creep and requires considerable resources to implement a software stack.

Zigbee offers mesh networking, low power, low cost modules and one module in particular offers an easy AT or API command interface.

This document disucsses the use of the Digi (formerly MaxStream) XBee Series 2 module for mobile robot data networking.


I use the following equipment to create a link between my host computer and the mobile robot:

Make Model Street Price Picture
NewMicros USB-XBEE-DONGLE-CARRIER 39.00 Photo of XBee USB Carrier board
NewMicros XBEE-CARRIER-5V 9.00 Photo of XBee 5V Carrier board
MaxStream XB24-BWIT 21.00 Photo of XBee Series 2 with wire antenna
Grand Total (includes 2 XB24-BWIT modules) 90.00

The XBee module comes with a selection of antennae. To chose which antenna best suits your needs, read Digi's Application Note on XBee Antenna. I chose the wire antenna for its improved performance over the chip antenna in outdoor applications.

The host computer uses an XB24-BWIT module installed in the USB Carrier. I plug the USB Carrier directly into the USB port on my computer.

The mobile robot uses an XB24-BWIT module installed in the 5V Carrier. I connect the wires from the 5V Carrier to the 5V serial lines on my MMB103.

A Better Breakout Board

After I bought the XBee carrier board above, a new board has become available. It makes all 20 XBee pins available, it is cheaper and most importantly, all the pins are labled!

The Firmware

The XBee modules have 4 different versions of firmware depending on whether you want a cross between AT or API mode and Coordinator or Router device. There must be exactly 1 coordinator per network.

XBee Series 2 ZigBee Firmware:

Module Role Version File
Coordinator AT mode 1020 xb24b_zigbee_1020.zip
Coordinator API mode 1120 xb24b_zigbee_1120.zip
Router/End Device AT mode 1220 xb24b_zigbee_1220.zip
Router/End Device API mode 1320 xb24b_zigbee_1320.zip