Posted by Jordi Muñoz on October 6, 2009 at 12:28pm
This is a rough/raw release of my ArduStation with tracking antenna support. In order to make it work you must calibrate your servo's range (pan 360 degrees, tilt 45 degrees). It uses your actual altitude and location against the altitude/position of your aircraft to accurately point your antenna. I guess the resolution is pretty good!What you need to do to make it work with ArduPilot:-Go inside the code an calibrate your sensors, using this line on the first tab://Servo Calibration!!!!Pan.attach(9,1000,1990);//PAN ServosTilt.attach(10,600,2150);//Tilt ElevatorThe second and third values are the min and max in milliseconds of the servos. (The first value is the Servo Pin Port)Then go to the definitions at the beginning and change these values. To activate them just change it for "1":#define TEST_PAN 0 //Test pan min and max (for calibration).#define TEST_SOUTH 0 //test south (the antenna will just point to south).#define TEST_TILT 0 //test the tilt max and min (for calibration).After you see your tracking antenna is working right, go to the flight field and point your antenna (in south test mode) to your true south... I chose south as a default because when you're between 1 and 360 degrees the antennas makes full rotations to jump from degree 1 to degree 360.You can download the lastest code here:ArduStation_V13.zip
The tracking antenna is working fine for me now. I needed to perform manual adjustments to the servos ranges in the Ardustation code but finally I could make it work.
Here is part of the code that worked better for my servos setup:
btw, I'm using a standard servo with a reduction to make the antenna perform 360 degrees. That's why I needed to reduce the servo rotation angle in the program.
I have a couple questions relating to setting this up with my Ardustation. I also have found that the link mentioned in #2 above by Leonardo (http://code.google.com/p/ardu-station/w/edit/AntennaGuide) still isn't working. Is there a correct link? Could somebody post it? How do you determine the correct "calibration" min/max values for the servos? The values above in the blog description seem pretty typical for the types of servos being used. How would you suggest optimizing these values? Lastly in the Ardustation v1.3 sketch there is a tab included for "SERVOS", it's blank. What is it's intended purpose?
Leonardo,
I hope by now you've found the answer to your 1st question, if not the DIY Drones store sells the GWS 125 2BB Sail Winch Servo (360° Rotation) here for this purpose.
Hi All, I'm planning to build my pan-tilt antenna to work with Ardustation and have two questions:
1. Do the pan servo needs to be a 360degrees fixed servo or one of those endless rotations servo should work also?
2. Where can I access further instructions on mounting/setting up the servos in Ardustation? I could not access the link that's in the Ardustation google source page (Driving a pan-tilt ground antenna http://code.google.com/p/ardu-station/w/edit/AntennaGuide ).
I'm using Ardustation with both Ardupilot and UAVDevBoard.
But it seems to have a refresh rate of only 1Hz.
I mounted a videocamera instead of the antenna, to watch at the capability of this hardware to track well the plane in flight. Results are that tracking is good (only a little to low vs plane altitude, yes I calibrate it ;D), but it is always late and positions changes are important.
Is it possile to increase this rate, both for the displayed data and, most important, for the pan/tilt servos, say at 4-5Hz, or at least at 2Hz?
Could you please tell me how?
Comments
The tracking antenna is working fine for me now. I needed to perform manual adjustments to the servos ranges in the Ardustation code but finally I could make it work.
Here is part of the code that worked better for my servos setup:
Pan.write(90-(Bearing_Home/4.0));
Tilt.write(constrain(90-Angle_Home,0,90));
btw, I'm using a standard servo with a reduction to make the antenna perform 360 degrees. That's why I needed to reduce the servo rotation angle in the program.
Cheers,
Leonardi
Leonardo,
I hope by now you've found the answer to your 1st question, if not the DIY Drones store sells the GWS 125 2BB Sail Winch Servo (360° Rotation) here for this purpose.
1. Do the pan servo needs to be a 360degrees fixed servo or one of those endless rotations servo should work also?
2. Where can I access further instructions on mounting/setting up the servos in Ardustation? I could not access the link that's in the Ardustation google source page (Driving a pan-tilt ground antenna http://code.google.com/p/ardu-station/w/edit/AntennaGuide ).
Thank you,
Leonardo
I'm using Ardustation with both Ardupilot and UAVDevBoard.
But it seems to have a refresh rate of only 1Hz.
I mounted a videocamera instead of the antenna, to watch at the capability of this hardware to track well the plane in flight. Results are that tracking is good (only a little to low vs plane altitude, yes I calibrate it ;D), but it is always late and positions changes are important.
Is it possile to increase this rate, both for the displayed data and, most important, for the pan/tilt servos, say at 4-5Hz, or at least at 2Hz?
Could you please tell me how?
Thanks,
Ric
Since the GWS winch servo is virtually dimensionally the same as a standard servo, the Lynxmotion servo driven pan mount would work in this case:
http://www.lynxmotion.com/Product.aspx?productID=578&CategoryID=75
The servo driven pan mount can accomodate up to 10 pounds which is easily enough for most antenna arrays.
I have several and they are easy to put together and would work well in this instance for a low cost pan base.
Just a thought.
Regards,
TCIII
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