Each XBee measures analogue or digital signals from the environment at its location,
and may be attached to a microcontroller for additional functionality.
These communicate wirelessly, using the IEEE802.15.4 and Zigbee
protocols, with a coordinator XBee attached to a Linux based processor
which collects the incoming data and passes it to storage. A remote
monitoring PC may perform control and configuration of the network through a local LAN or Internet.
This page describes software developed as a foundation for building a network of the above type. More documentation is provided in a LibreOffice file. All code and PCB files are provided via a GitHub repository.
(Note: software is licensed by the Apache licence which allows free copying for commercial projects, with protection).
The remote node must have an XBee in Router or End Device mode. The
latter allows the XBee to enter sleep mode for power saving. The XBee
communicates with the coordinator XBee to pass command and data.
A microcontroller node may have a bootloader for remotely
installing application firmware. A bootloader has been developed for the Atmel
ATMega168 but can be extended to other AVR microcontroller types with sufficient FLASH memory via a simple
change. It is written in C specifically for AVR microcontrollers.
AVR program needs to communicate with the attached XBee using the
so-called API messages via the serial port. The firmware provided has a
number of forms for testing. The main firmware is designed specifically
for a watermeter project transmitting battery voltage and a count of
transitions on a digital port of the microcontroller. An ACK/NAK
protocol is used to reduce the probability of loss of data due to
adverse network conditions.
The process xbee-acqcontrol
is a program running continuously as a
background process on a Linux based (assumed Ubuntu here) computer referred to as the Base Station. This provides an interface
between the XBee network and an external user interface. The computer
could be as small as
a Raspberry Pi and is intended to sit permanently powered and
unmonitored in the proximity of the network with an attached
coordinator XBee. The program is written in C and relies on the libxbee libraries written and maintained by Attie Grande. It monitors the
XBee network, collecting data messages and passing them to local
storage. It also interacts with external PCs for monitoring and
configuration by passing messages through to the remote or coordinator
XBees. The software requires the libxbee
package to be installed and compiled. This can either be installed to
the system or the libxbee.a (binary library) and xbee.h (header) files may be copied over to
the directory where the coordinator software has been unpacked.
The results files are stored in a predefined directory
by default is /data/XBee. This must be created and the permissions set
to allow writing by the user under which the program is run. If another
desired it can be specified as a parameter at program invocation.
There is a setting in the xbee-acqcontrol.h file to define a
DEBUG symbol. This should normally be commented out. However if debug printouts
are desired leave this uncommented and run the program from a terminal.
Certain messages are printed to the syslog local7 facility, which must
be setup in one of the /etc/rsyslog.d files (see documentation for details).
coordinator XBee must be present. The program currently
looks for a device in /dev/ttyUSB0 by default but the device can be
specified in the command line options. These device files appear when a
USB to serial
converter is connected, such as would be the case for a USB adapter for
the XBee. If running under a user
other than root, add the user to the dialout group. The baud rate
defaults to 38400 baud but this also can be specified as a command line
the process is started it issues a node discovery packet and delays
for 10 seconds to await identification responses. These will come from all XBees that are awake. External programs
cannot connect to the process before this time is complete.
The process can be started with:
$ ./xbee-acqcontrol -D data-directory -b baud-rate -P serial-device
Where each option can be omitted
or placed in any order as
desired. Typically the process will be started on bootup of the
machine. Other options are -d for debug level 1, -e for setting other
debug levels and -L for setting logging to disk with logging level.
Check in /var/log/syslog for any error messages.
user interface or monitor program is written in C++ and uses QT5 for
support. It currently runs under Linux but could be adapted to a
Windows or OS/X environment. This provides basic control of the
coordinator process and
configuration of the XBees. It can be expanded and developed as needed
particular applications. The QT packages must be installed for
compilation and use. There is a setting in the xbee-control.h file to
define a DEBUG
symbol which should be commented out. However if debug printouts are
desired leave this uncommented and run the program from a terminal.
Run the program from the directory containing its binary with:
By default the
coordinator program listens on the TCP port 58532. If attempting to
connect from the Internet, any intervening routers and firewalls must
be set to port-forward to the coordinator IP address on this port (note
that on some routers Port Forwarding is called "Virtual Server").
the GUI and in the top left edit box enter the IP address or domain
name of the coordinator machine. The example below has the coordinator
running on the same machine as the GUI.
"Connect" to make a
connection. The table should show a list of the nodes in the network as registered by the base station.
The coordinator is not shown. The nodes above marked with an asterix
had been detected in an earlier run, but on this occasion were not
detected. This feature allows dead or removed nodes to be identified. A
sleeping node may also be so marked if it wasn't detected at startup.
configure the XBee in a node, select the checkbox on the right and
click "Configure XBee". This brings up another window after a delay.
This may take some time if the XBee is sleeping, but it will wait for a specifid time.
This allows a number of relevant configurations to be made, notably the
analogue and digital I/O, sampling interval and sleep options (in the
case of end-devices only). Click "Write Values" for these to be made
coordinator attached to the coordinator processor can be configured by
clicking "Configure XBee" when no remote node is selected. Note that if
more than one node is selected the lowest numbered one is used.
If a node has been powered off or
removed from the network then its entry in the table can be deleted by
selecting it and clicking "Remove Node".
If the node has an attached
microcontroller with a compatible bootloader, then new firmware can be
uploaded by clicking the "Firmware" button. A progress bar will appear.
Note that the upload process can be quite slow particularly for busy
If a new node is inserted and the
XBee has been properly configured (see the documentation for suitable
settings) then on power up should will send out an identify message.
The coordinator program should intercept this and add the node
automatically to the table. If this doesn't happen for some reason,
then the node's 64 bit serial number (in hex) can be entered in the top
right edit box, and "Query Node" will attempt to contact it. The text
node name (node-id) can also be used but this is less likely to work.
is available only for Linux and has been tested under Ubuntu (although
in principle light weight distributions without desktop would
be more appropriate). It is written in C and compiled with the gcc compiler.
Download the libxbee source code and follow the instructions
in the README to compile it. This should just require "make configure"
and "make all" to install the libraries to a suitable system library directory.
Download the XBee-Acquisition
package from GitHub into a suitable directory. Go into the
XBee-acqcontrol directory and compile using "make". The makefile is
generic and should work without modification on any system.
error messages are to go to a specific log file rather than
/var/log/syslog, edit the /etc/rsyslog.d/50-default.conf file and add
This will allow the program to write messages to
the designated log file.
A directory is needed to store the files of data
received from the remote nodes. This can be entered as a command line
$ ./xbee-acqcontrol -d /data/XBee
where the directory must exist and be writeable by
the user running the program (if other than root). The directory /data/XBee
is the default.
Finally to get the program to run with a non-root
user, add the user to the dialout group, then log out and back in:
$ sudo adduser username dialout
Monitor (Linux Version)
For Linux use, the following QT5 development packages should be installed: qt4-designer, qt5-qmake.
Apart from this the program only uses the standard POSIX
Build the program with
Monitor (Windows Version)
Note: The program has been modified to compile under QT5.
Therefore either modify the instructions below to use QT5 or download
an earlier version of the software on or before December 24 2014.
For development or compilation on Windows, download the QT
opensource version 4.8.4 for Mingw 4.4
Install to its default folder.
These versions date from early 2013 but the versions
QT 4.8.6 for MinGW 4.8.2 should work provided the available version of
MinGW is compatible.
There may be difficulties encountered
installing to 64 bit machines if the binaries are 32 bit. This will
usually result in missing libraries during the linking stage.
Download the Mingw install GUI
Also install to its default folder, as that will be used by default
by QT. Copy the source files for Xbee-GUI to a folder C:\Xbee-GUI. From
the start menu, open the QT 4.8.4 command prompt in the "QT by Digia
v4.8.4" (or similar) entry. In the window, change directory to C:\Xbee-GUI and issue the commands:
The executable will appear in the “release”
folder. To make it distributable, add the following files from the MinGW\bin and QT\4.8.4\bin folders:
The resulting set of files can then be bundled
into a zip file for distribution and should run on any compatible Windows
installation without additional compilation actions needed. This has been tested on Windows 7.
bootloader is written in C and is compiled using avr-gcc which is
available in the Ubuntu repositories. It should be possible
to compile also under WinAVR on a Windows machine.
1. Update Windows version of Monitor program to QT5.