Jean-Luc replied to the topic 'Alt-Az mode for EQmod' in the forum. 7 months ago

I've played a little yesterday evening with the skywatcherAltAzMount driver. I've used the AZEQ5, 150/750 scope with a DMK41 and a 50/206 guider with a ASI120mm. Nothing aligned. Capture/solve/slew to target works great with the ASI120@206 in 4/5 iterations, but strangely with DMK41@750 it solves but does not slew at all. I suspect a problem with V4l2 devices as the laptop also has a webcam. Sync is not working, there were 3 sync points that I tried to delete, but then tracking became weird. Looking at the code, Sync is only allowed when the mount is parked. I made some images of Dumbbell @10, 30, 60 and 120 seconds to observe star drift/rotation. A silly question, I wonder if the field rotation axis is always centered with the sensor center, or is actually the scope axis. By the way I also noticed regular jumps as depicted by @Federico. I suspect the Aux encoders which are not disabled on AZEQ, and/or the tracking algorithm which updates its data every minute. Lastly I tested guiding, when calibration succeeds (I suppose RA/Az axis does not move enough at ~50° altitude using standard guiding rates), those jumps disturbed the algorithm too much (added to field rotation as the guide star was selected on an edge of the image). Guiding in AltAz mode is quite silly, however the guide tool shows the drifting graph (see the jump @45s) and almost every points are in the upper right corner (field rotation presumably, I did not make the calculations). I may use that to test Alt/Az tracking, selecting a centered star as guide star.
Thus I've learned a little more, and your posts also help me to understand what were your concerns and what you would need. As I understand it, alignment is not primordial as long as Capture/Solve/Slew is working, guiding is of no use as your setup does not have a guider, and you only really need a smooth tracking. What I have in mind as a first step is to create a new driver out of the existing indi repos, hence astroberry users may compile it without disturbing their installation. I will derive it from indi-eqmod and/or indi-skywatcherAltAzMount and then concentrate on the tracking feature. I'll keep you informed when that will be initiated and when I will need you to perform tests.

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