Now that you have plans for a ZigBee network, you should think about how you will debug and test it. After all, you may have dozens of nodes and lots of information passing between them. Enter the sniffer. Basically, a sniffer listens to all ZigBee communications and puts the information in a format that can help you determine what transpires on your network.

Figure 1. The Zena wireless network analyzer board ‘sniffs’ ZigBee and MiWi communications. Software breaks the communications into packets and displays them so developers can monitor and debug communications. Courtesy of Microchip Technology.
The PICDEM Z 2.4-GHz kit from Microchip comes with a Zena wireless-network-analyzer board (Figure 1). The analyzer can acquire and decode information presented in either the ZigBee or Microchip's MiWi protocol. The accompanying software can analyze network traffic, graphically display decoded packets and display a diagram of the network topology and the messages that travel from node to node.

"As we developed the PICDEM Z boards, it became a challenge to debug a system of more than two nodes," explained Rodger Richey, senior applications manager in the Advanced Microcontroller Architecture Division at Microchip Technology. "We could not find an inexpensive tester, so we designed the Zena board and developed software for it. The software lets developers 'see' nodes join a network and messages that pass among the nodes. And you can record all this activity." The PICDEM Z kit comes with the Zena board and software, but developers can purchase a Zena sniffer separately. The Zena board will ‘sniff’ any ZigBee communications, so you can use it with any ZigBee network.

The two Texas Instruments ZigBee development kits, CC2420ZDK and CC2430ZDK, come with Packet Sniffer software that runs in conjunction with the PC-based network controller. ZigBee radios from TI and other companies also work with Sensor Network Analyzer software from Daintree Networks. The company offers several packages, from a Standard Edition to a Professional Edition. Module and IC companies may provide other network-analysis tools in their development-kit packages, but you may have to hunt through their Web sites to find information.