I have been having trouble determining the antenna tracker parameters for the APM Mission Planner. I have gotten it to work within the Pololu Maestro software with the parameters:
Min: 1312, Max: 1584, Startup: Goto 1450, Neutral 8-bit: 1448, 8-bit Resolution: ~136
--Setup so that it can rotate +- 180 degrees from "neutral"
Min: 1584, Max: 2200, Startup: Goto 1976, Neutral 8-bit: 1892, 8-bit Resolution: ~308
--Setup so that it can rotate from straight forwards (parallel to horizontal) to straight upwards (parallel to vertical).
USB Dual Port
My problem is three fold:
1. Which port do I use to communicate with the Maestro? The Command or TTL port?
2. What baud rate should I be using?
3. What numbers should I set the angle and PWM parameters to, within the mission planner?
Thank you in advance for your help.
the neutral value should always be in the middle of your range.
1. try both... only one will work.
2. any, it auto detects.
3. have you followed my guide?
1 & 2: Thanks.
3: Yes, I have followed it, multiples times, to no avail. Here are my settings within the Maestro Control Center which work perfectly and as expected: http://i.imgur.com/NzZda.png
Here are my APM settings: http://i.imgur.com/ipyk6.png
Here is the result: http://www.youtube.com/watch?v=gqtLvD9nqgA
If you can provide any insight at all, it would be much appreciated. Thank you.
ok hear are the setting i would use
1328 1568 mid 1463 range 135
1584 2400 mid 1992 range 408
your tilt servo looks ok and within range. you pan servo mid looks off.
Thank you, I will try those settings when I get the chance. Do you know what would be causing the disassociation between the angle reported in the APM and the actual angle of the servos (e.g. APM reporting 90 degrees while it has actually done a 180 degree rotation)? In addition, what would be causing the servos to go the opposite direction after a certain degree as reported by the APM (e.g. the tilt servo going back in the other direction after reaching the top)?
Once again, I appreciate your time.
PS: How do you see the angle reported in APM?
I'm very glad I found this thread. I have followed the following guide to the letter:
http://code.google.com/p/ardupilot-mega/wiki/AntennaTracking?ts=134..., but I'm not having much luck.
My setup is the HSHS-645MG servos for both pan and tilt. Pololu Maestro 6 channel servo controller.
This results in a reliable 180 degree radius turn (90 degrees both side) and 90 degree tilt. I'm using the readmaderc.com hardware setup (pod).
Tilt seems to work OK, but pan is a complete mess. My calculated values are:
pan: min 1120, max 1888, 8bit range 384, pwm range: 768. MP set to 180 degrees
tilt: nub 1988, max 1877, 8bit range 394, pwm range: 789. MP set to 90 degrees
Neutral range is set to 1500 in both cases.
Now, my other problem is as follows: the wiki states to always point the AT North. Then set the tracker home location (in the Flight planner screen). The problem is that at my house, the 'home' location of the drone is at 90 degrees (East) of the tracker home location: in other words already at the max right movement.
What I really like is to point the antenna at the drone's home location so that it has 90 degree left and 90 degree right turns available.
Also, because tilt's center is 45 degrees, I need to trim the tilt to horizontal. Is that correct?
Any help would be greatly appreciated!
Alright, so basically your values are correct. The problem, I discovered, is rooted in the difference in how those values are given to the controller from both the Maestro controller (software) and the APM. The APM uses a shorter protocol than the Maestro. I.E. The Maestro is more precise -- for the APM, 0 is your lower limit while 254 is your upper limit whereas in the maestro, your lower limit is 1120 and your upper limit is 1888. In other words, because the APM uses a protocol that is less precise (a range of 255 possible positions) than the maestro's protocol (a range of 668 possible positions), the ground station software is a bit finicky. I have modified the code so that it uses the more precise protocol and will be submitting it for integration into a release.
I will post here if that ever happens. Good luck with your project!
Thank you. I have found that sometimes either pan or tilt will not respond at all, as the Maestro may stay 'active' after changing some settings on it. Will try that out later, but it will be a few weeks.
williams mod is now live. with some editing from me
Thanks. I'll give that a try as soon as I can. Probably in 2 weeks (work travels).
Hi chris, in your instructions you mentioned that the antenna is supposed to point North when setting it up. Am i right to assume that this reference North is in fact true north and not magnetic north?