XBee choice and configuration
The wireless transmission is done using the XBee wireless chip.
- transmission frequency: The XBee chip is available in various flavours, either for the 900 MHz or 2.4 GHz range. We have only worked succesfully with the 2.4 GHz version. The 900 MHz ones have a different type of firmware with different settings.
- range: XBee and XBee Pro. The latter has a longer range than the regular XBee and can be useful for outdoor sensing. The two types can be mixed within one network.
- series: The XBees that we have worked with successfully are the 802.15.4 (or Series 1);
Series 2 (Zigbee/ZNET) does not allow to both send data to a coordinator node and send data out to nodes (bidirectional transmission), which makes it unusable for the SenseStage MiniBee.
The XBees can be configured with the Digi software tool X-CTU (see below).
The following settings are of interest to change:
- ID: This is the PAN ID, the identifier by which the XBees will know that they belong to the same network. All your XBees should have the same number here.
- DH and DL: This is the address a node will send data to. For SenseStage we usually work with DH=0, DL=1 for the coordinator node, and DH=0, DL=0 for the regular nodes. If you want to send data between the nodes themselves, you need to use another setting. The coordinator could also use DH=0, DL=FFFF, which broadcasts to all possible destinations.
- MY: This is the address for the specific node. For SenseStage we work with 0 for the coordinator node, and 1 for a regular node. If you want to send data between the nodes themselves, you need to use another setting.
- CE: This is the “Coordinator enable”. Should be 1 for the coordinator and 0 for the regular node.
- BD: Setting for the baudrate. 19200 (as used by MiniBeeV2; library version 2) is 4; the latest version of the firmware library (just called MiniBee) works with baudrate 57600 (BD 6). Should be equal between coordinator node and regular node.
- SM: Sleep mode. This should be 2 (pin doze) for the regular node. For the coordinator node it depends whether or not the sleep pin (pin 2 of the XBee) is pulled low on the coordinator board. In case of doubt, set this to 0.
Download: XBee profiles for Series 1
- Digi Website, look for X-CTU (links below may be outdated)
- Program http://ftp1.digi.com/support/utilities/40002637_c.exe
- User Guide http://ftp1.digi.com/support/documentation/90001003_A.pdf