My Arducopter has a 1.280 Ghz video transmitter and camera for sending live video down to a groundstation. Initially I used a fixed ground antenna to match an onboard dipole transmitter antenna and found that multipath was a severe problem when flying in an area with many structures. The ground antenna is a high gain patch and isolates the multipath if it is pointed directly at the Arducopter in flight. Having seen tilt/pan antennas for FPV and UAVs on the Internet, I started looking for a inexpensive solution that could use the datalink transmitted GPS location information to point my high gain patch at the quad during flight. My search led me to an inexpensive tilt/pan antenna system from readymaderc.com:
Antenna Pan/Tilt for EagleEyes Antenna Tracker
This tilt/pan assembly comes by default with Hitec HS-485HB servos which have enough torque to operate my patch antenna and video receiver. Once installed, the servos are geared to operate from 0 to 90 degrees in tilt and 360 degrees of pan. One disadvantage is that the assembly must rotate a full 360 degrees when exceeding the stop in either direction although this happens very quickly in my experience.
To operate the Tilt/Pan assembly, I have modified Phillip Anthony Smith’s Mavlink Ardustation software to include tilt/pan commands driven by received Mavlink GPS position. RAM is very tight in the code and is focused on APM, but I manged to add a few new screens to output tilt/pan info and set/display home information for the antenna location. I had to remove APM pid modification screens to make my changes fit in RAM. This is problematic if you want a complete replacement for a ground station, but it was not a problem for me since I also use a second Xbee with a notebook to monitor the Arducopter. I just use the Ardustation for antenna positioning. I’ve also added code to position the location of the pan stop to the least obtrusive position at the flying site. The following video shows the readmaderc.com antenna tracker in operation and some tips for using the software. The software can be downloaded here for others to modify or use as they see fit.
Note: The libraries distributed with versions of Arducopter 2.0.40 and later will get compilation errors due to changes in the Mavlink headers within the library. You can compile with the library contained in the Arducopter 2.0.36 source code distribution and the Ardustation software will still work with Arducopter 2.0.40 to 2.0.46. I’m working on source code changes to allow compilation with the modified Mavlink libraries.
A new version has been released that fully supports Arducopter and ArduPlane, parameter editing, antenna tracking, and autodetection of which platform is connected. This version also compiles with the latest libraries in ArduPlane 2.24 and Arducopter 2.0.48/49. The latest Ardustation 2 software is 2.0.11.
New development and fixes for source here
Original ArdustationPSTilt/Pan Arduino Source
192.168.18.125
18.188.218.226