Hi, I'm searching for a project to re-use an old APM 1280 as Antenna Tracker,
Do you know anything interesting?
I'm very happy to fly a worderfull APM 2560, but now I need and "Ardustation".
With the new feature of APM Mission Planner (ctrl-g) that allow a serial output of NMEA data is it very hard to build an antenna tracker with ours old 1280 boards?
Thanks a lot to everyone for the great job they are doing!!! (& sorry for my poor english...)
you can this Ardutracker-mega code I scrambled together a while back; and use HappyKillmore's GCS for an antenna tracking using your 1280.
Dont know if that worked or not, if not, Try this link
Hi Darren, thanks a lot,
do you have any documentation about the pan/tilt servos connections?
and how i can connect the 1280 to the HK?
What I think is that I wish to use APM Mission Planner connected with the Xbee to my plane and have an antenna tracker guided by the NMEA data from another serial port.
How about the following approach:
* Align the antenna tracker with the help of a compass.
* Connect the XBee directly to your PC and the Mission Planner
* Attach the Mega 1280 to a USB port on the PC via a USB-Serial converer.
* Let the Mission Planner send NMEA data to that serial port
* You need to store the antenna location in the Mega 1280 to be able to calculate direction to planes location.
* Add a button on the Mega 1280. When your plane is starting to send reliable data to the Mission Planner and after pressing cntrl-G, press the button and store current position and altitude as home. This requires that your plane is somewhere near the antenna.
* After releasing the button you should be all set.
* I guess you could store the first position you get from the Mission Planner as home automatically as long as you get valid data.
The code for the Tracker should not be that complex:
* Parse incoming nmea data
* If button is pressed store incoming data as home else
* calculate a vector from home to current position
* Set pan and tilt servo to a position matching the vector.
something like that...
You Hit the Mark.
But we do not have to forget that the NMEA data are delayed by about 2 seconds, so we may add a "predictive" function that allow to anticipate the real plane position calculed based on distance from the home position.
I love this "hobby"....
Why limit ourselves? Why not use APM 1280 to provide complete autonomous attitude control for our tracking antennas? The tracking antenna could have it's own GPS to simply home position setting and make it operable in a moving vehicle when combined with a magnetometer. No more calibrating positions would be great or maybe I'm just incredibly lazy, probably some of both. :)
Limit ourselves? why?
Don't forget You're flying a fully autonomous plane..
I've builded a wonderfull Bixler and I've a range of 40Km. In the past days I've done a great record for me, 1500 meters hight with a distance of 20km from the home without loosing telemetry!!
This is my tracker:
Now it work with an Eagletree system, and I wish to use a new tracker.
I work in a Italian informatic's company, so I've asked to my collegues to try to develop some code for the tracker.
I keep you updated!
What is the best strategy for rotating the antenna to follow the plane? If you are using a servo i guess you need to decide what to do when you reach end of servo travel. If i use a for example stepper motor you will twist your antenna wires...
Or do you just plan your flight to take place in a defined sector?
How does your current tracker work?
As you can see in the attached video (http://youtu.be/X9zsvX1v-1Y) now I'm using two standard servos. (15KG load)
My antenna now can pan for 180 degrees and 180 degrees for tilt, so if I need more than 180 degrees in pan movement I flip the antenna on tilt axis and to obtain 180 degrees of range in the opposite pan direction.
Eagleetree has a very difficult and imprecise calibration method, and I think that is possible to do the same calibration using a very simple method:
1) I always place my antenna pointing in north directon
2) i give other parameters like these:
a) 1130 (servo pulses) is west (pan)
b) 1900 (servo pulses) is east (pan)
c) 1130 (servo pulses) is Notrh (tilt)
d) 1900 (servo pulses) is South (tilt)
now I the tracker know :
1) The Home position (APM power-on location) and know that it is pointing North
2) The travel limits
All antenna movements are linears.
Hi! the two links above has broken, could you re-link again? thanks
Hi! Finally I can read GGA code, but I think MP don't work fine, it send wrong data in serial output, it don't agree from data on screen's bottom. For example
MP LAT : 39.5878 (decimal format) must be GPS_FIX= 0 or 1 or 2
Arduino LAT 39.2474 (unknow format, and don't change) GPS_FIX = 3¿!?!¿!?!
Somebody has any idea?