provides a configuration utility
called XCTU on their website
Download and install this tool. It
is available for Windows, Mac,
and Linux systems. Digi has
even produced a short
introduction to XCTU video that
is helpful to watch (https://you
XCTU, you can easily upgrade
the firmware of XBee radios,
check the signal strength and RF environment, and
configure settings of all devices on an XBee network.
By now, you probably have the FTDI Virtual COM Port
(VCP) drivers installed on your system, but if you don’t, go
ahead and do so. The drivers are available on the FTDI
website for most operating systems (
/Drivers/ VCP.htm). You’ll need this to communicate with
the flight controller and the ground side radio.
While you’re dealing with software, go ahead and
make sure your flight controller and ground station are up
to date. Just after the publication of the ELEV- 8 v3 review
article, the flight controller and ground station received
updates with the release of version 2.0 of the software.
This software offers some great stability improvements and
is worth taking the five minutes to upgrade.
If you need some help uploading the new firmware to
the flight controller, be sure to check out the instructions in
the October 2016 article. The most recent versions of all of
the software can always be downloaded from the Parallax
GitHub repository (
https://github.com/parallaxinc/Flight-Controller). Just click on the “Releases” tab and download
the most recent set of files. You must be running the same
version of the flight controller firmware and ground station
software for things to work.
It is worth keeping an eye on the repository as there
are always changes being made to the software (the
ActiveDevelopment branch containing the most bleeding-edge versions). There is also an “Issues” section where you
can see what bugs are currently reported and what new
features are coming down the pipeline. The Parallax forums
https://forums.parallax.com) are also a good place to
visit. Most of the ELEV- 8 discussions there occur in the
Robotics section of the forum. First, we need to set up the
correct baud rate on each of the two XBee radios. To do
this, we’ll put each radio in the XBee USB adapter board,
connect an antenna, and connect it to the computer
(Figure 2). Never power up an XBee without an
antenna attached! Powering the radios
without an appropriate antenna connected can
cause permanent damage to the radio.
So, connect an antenna (included in the kit) to the
RPSMA connector and plug in the adapter board with a
mini USB cable. Open up the XCTU application. Once
inside, click on the “Discover Devices” icon that looks like an
XBee module outline with an hour glass (Figure 3). A
window will come up asking you to select which COM port
to look on — select the port associated with your USB
adapter board (Figure 4). If you’re unsure, disconnect the
board, click “Refresh Ports,” then reconnect and click
“Refresh Ports” again. The port that disappeared and then
reappeared is the one you want.
Once done, click “Next” and set the parameters to use
when connecting. With new modules, the defaults will be
fine. If you have already configured the modules or are
reusing modules, adding more baud rates to the list could
be useful. I generally added 57600 and 115200 baud for
future use (Figure 5). Once done, click finish and XCTU will
scan for any attached radios.
After the scan completes, the module will show up in
the left-hand pane of the application. Click the module and
wait for the software to load up and display the settings for
SERVO 01.2017 9
Figure 2: Clip one of the radios into
the USB adapter, add an antenna,
and it is ready to plug into the
computer for configuration.
Remember that you should never
power up an XBee with the antenna
Figure 3: The “Discover Devices” button is in the upper
left-hand side of the XCTU window (circled in red).
Figure 4: Select the appropriate COM
port for your USB adapter. In my case,
it was the only device plugged into my
Microsoft Surface at the time.
Figure 5: Select the search
parameters used to discover
devices. I add 57600 and
115200 since those are
common settings used and
ones that we will use later.