Calibrating Rotator

Hello There! I now have my ground station all set up- the last step is to calibrate the rotator to the right degrees. I have a Yaesu G5500. How do I determine what 0 degrees is? Any tips?


Hi Kaylee,

The G5500 has physical “end stop” switches at 0 degrees and 450 degrees Azimuth (overlapping 360 degrees by an additional 90 degrees). Between these is a potentiometer that tells the control box where it is pointing at in that spectrum.

My suggestion is before tightening the rotator on the mast, plug in the control box and turn it all the way to the left (CCW) until the rotator completely stops. This is your 0 degree point. You can then mount the rotator permanently pointing it North.

You will want to then turn the rotator all around to 360 degrees (back to the North point) - if the needle on your control box is not at 360 when you have it pointing directly back at North you may need to adjust a potentiometer on the back of the rotator box.

Do this similarly for the Elevation control, 0 degrees (flat) should be the very bottom end stop. I would then point it straight up and adjust your needle to be 90 degrees.

hope that helps!

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Thanks so much! It’s calibrated now- but the new issue is that it isn’t rotating for the observations automatically! I had it working indoors, but now that I have moved it outdoors it doesn’t work and I can’t figure out why. Any thoughts?

Check all the cables?

Does the rotator still work if you manually control it (on the rotator box)?

Are you running the satnogs raspberry pi image or some other method?

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The rotator does work by manual control, and yes, I am using the satnogs raspberry pi image :slight_smile:

Ok! What interface do you have between the rotator box and the raspberry pi?

run sudo satnogs-setup

go to the bottom of the basic page, select HAMLIB_UTILS_ROT_OPTS and paste what you have in here.

I am using a Yaesu GS232B Computer Controller to interface between the rotator box and the raspberry pi, using a RS232 to USB converter.

I have:
-m 603 -r /dev/ttyUSB0 -s 9600 -T

hmm ok - on the raspberry pi itself:

sudo apt-get install telnet
telnet localhost 4533

then, assuming it connects, type:

P 45.0 45.0

(and hit Enter) Does the rotator move to 45 azimuth and 45 elevation? If so the rotator control interface is working. If not we need to start debugging rigctld.

No need for telnet: the rotctl CLI to rotctld should be installed with hamlib.

pd@main_bus_B:~ $ rotctl -m 2

Rotator command: P 090 045
Azimuth: Elevation: 
Rotator command: p
Azimuth: 90.000000
Elevation: 45.000000

Rotator command: q
pd@main_bus_B:~ $ 

Debugging is also easy with that: add some -v to get more informations (the more v, the more debug data).

So when trying to run a command it says:

“set_pos: error = Communication timed out”

Not quite sure what to do with that…

Thanks for the continued help!

Try to run rotctld (watch out for the trailing “d”!) with a lot of debug info enabled, like:

$ /usr/bin/rotctld -vvvvv -m 603 -r /dev/ttyUSB0 -s 9600 -T

To ensure you stopped the rotctld previously started, simply do a:

$ sudo killall rotctld

Open a second terminal and run the command as I mentioned in my previous post.

I guess there’s one of two things wrong: the ttyUSB or the baudrate, maybe the wiring also :wink:
This might be three things :smiley: