Khalid created a new topic ' Question on units and tolerance for slews' in the forum. 2 months ago

There is a piece of code in various scope models, such as Astro-Physics, FS2, and I implemented it for the Sky Sensor 2000 PC as well.

For example, line 439 Astro-Physics driver .

The code is like this:

double dx = targetRA - currentRA;
double dy = targetDEC - currentDEC;

if (fabs(dx) <= (SlewAccuracyN[0].value / (900.0)) && fabs(dy) <= (SlewAccuracyN[1].value / 60.0))
 ... slew is complete

So the question is what units are targetRA and targetDEC?

Why is RA divided by 900 and Dec by 60? Being different units would explain this.

Is the SlewAccuracyN really arc minutes or something else?

Thanks for your feedback.


Khalid replied to the topic 'Bresser Exos Goto?' in the forum. 2 months ago

Does not directly answer your question, but closely related to it.

Explore Scientific sells the Bresser Exos2 with an open source controller called PMC8.

Here it is:

This is the controller

And the programmer's reference manual for it:


Khalid created a new topic ' Fix for slews not completing on Sky Sensor 2000 PC' in the forum. 2 months ago

When using KStars (or Cartes du Ciel) with the INDI driver for the Sky Sensor 2000 PC (lx200ss2000pc), sometimes a slew will never end, and that will cause the mount to not respond to any slew commands until the driver is stopped and restarted, or an abort command issued.

In order to solve this, I added configurable slew accuracy in INDI for RA and DEC. A value of 4 arc minutes seem to work well with my mount (Vixen GPDX).

Please incorporate this pull request to the repository.


Khalid replied to the topic 'Polar Align Assist never completes its run' in the forum. 5 months ago

Yes, this fix has been in the daily build for quite some time. If you are not using the daily build, then any package from more than one and a half months ago has the bug. The bug only occurs on slower machines though.


Khalid replied to the topic 'indi_canon_ccd segfault' in the forum. 6 months ago

Does not crash anymore!

Thanks a million ...


Khalid thanked Jasem Mutlaq in topic indi_canon_ccd segfault 6 months ago
Khalid replied to the topic 'indi_canon_ccd segfault' in the forum. 6 months ago

I use a Canon EOS 650D, with the daily build of INDI.

The camera worked when used with images.

However, when using LiveView, it works for the first and/or second time you invoke LiveView. But on the second or third, INDI crashes, and the kernel has this in dmesg:

indi_canon_ccd[4407]: segfault at 7f986dd03000 ip 00007f987b0351c7 sp 00007ffcba6d2aa0 error 4 in[7f987b003000+da000]

When I applied today's build, the problem still happened.

I rebooted (Linux loads the new module), and the problem seemed to go away.

But after some testing the driver crashed.

The test is simple: invoke LiveView one or more times, exiting after each time. Then take one Preview frame. Then when you invoke LiveView again, the crash will happen.


Derek thanked Khalid in topic Post your INDI Setup! 6 months ago
Khalid replied to the topic 'Post your INDI Setup!' in the forum. 6 months ago

On one session, I tested guiding with the main scope and camera first. In INDI, under 'Guider' I select the main Canon camera, and under 'Via' I would select the GotoNova mount itself, and then see how calibration is doing.

The result was a 'calibration failed' or something similar consistently. That what dissuaded me from taking this idea further.


Khalid replied to the topic 'Post your INDI Setup!' in the forum. 6 months ago

In theory yes. In practice, I don't think it would work well. This assessment is based on the fact that in Align, when selecting Slew to Target, it keeps trying for 10 or more times, and says accuracy is not met, and tries again. Don't know if it is gear or motor precision/backlash or what. The other thing is PEC. Even though the hand controller supports PEC, I tried it more than once and it made things worse, not better.


Khalid replied to the topic 'Post your INDI Setup!' in the forum. 6 months ago

I am amazed at all the observatories, and remote setups in this thread.

My setup is very simple in comparison, but INDI/Ekos make life much easier.

What I do NOT have:

- Autoguiding: my mount has no autoguiding port, and I don't want the weight and complexity (yet).
- Motorized focusing: I focus manually at the beginning of the night.

Mount: Celestron CG5 with the GotoNova 8400 Upgrade Kit, and 8401 hand controller.
Optical Tube: Celestron C8 with Starbright XLT, with F/6.3 Focal Reducer Corrector (1085 mm focal length)
Camera: Canon EOS 650D, with 2 inch adapter
Focuser: JMI EV2 2 inch focuser (it adds to the optical train length hence focal length is not 1280 mm). This is not strictly necessary, but it came with the scope package, and allows 2 inch accessories to be used.

All this is controlled from an old laptop (now a 2009 Toshiba Satellite A300, with Core 2 Duo).
The laptop has Xubuntu (XFCE) 16.04.3, with KStars and INDI.

The laptop connects to the home network by WiFi, and I use NoMachine to login to it and run KStars/Ekos from inside.

Since I don't have autoguiding, I am limited to 30 seconds of exposure. I don't do stacking or postprocessing for many reasons, and the 30 second exposures are acceptable for now.

My workflow shuns eyepieces and visual work completely. Even focusing is done on the DSLR's LCD from LiveView at the start of the evening. I setup everything, do a rough polar align using the built-in polar scope, balance the scope, wait for something to focus on, then go inside and commandeer the scope from there. Plate Solving alignment is magic, and the killer feature for this setup. I then point the scope to targets and take one exposure to check everything is good, then create a sequence of 5 or so pictures, and let it roll, then move to the next target.

The tedious part is setting up and removal of equipment every night.


Khalid replied to the topic 'How to debug mount not responding to commands?' in the forum. 6 months ago

Last night was a completely trouble free night. No glitches. The scope was accurate from INDI, and Polar Align procedure completed successfully.


Khalid replied to the topic 'How to debug mount not responding to commands?' in the forum. 6 months ago

How can I disable the :pS# command?


Khalid created a new topic ' How to debug mount not responding to commands?' in the forum. 6 months ago

How does one go about troubleshooting or debugging a problem when the mount becomes unresponsive for no apparent reason:

Here is an example. Commands are issued, and there is a response, then suddenly, no responses at all:

SCOPE   7000.078862 sec : CMD <:GR#>
SCOPE   7000.100635 sec : RES <18:19: 4.1>
SCOPE   7000.100714 sec : VAL [18.3178]
SCOPE   7000.100732 sec : CMD <:GD#>
SCOPE   7000.121625 sec : RES <-13*46:55>
SCOPE   7000.121703 sec : VAL [-13.7819]
DEBUG   7000.121721 sec : CMD: <:pS#>
DEBUG   7000.137620 sec : RES: <East>
SCOPE   7001.138734 sec : CMD <:GR#>
SCOPE   7001.160656 sec : RES <18:19: 4.1>
SCOPE   7001.160734 sec : VAL [18.3178]
SCOPE   7001.160753 sec : CMD <:GD#>
SCOPE   7001.181639 sec : RES <-13*46:55>
SCOPE   7001.181715 sec : VAL [-13.7819]
DEBUG   7001.181733 sec : CMD: <:pS#>
DEBUG   7001.197771 sec : RES: <East>
SCOPE   7002.198163 sec : CMD <:GR#>
SCOPE   7002.219656 sec : RES <18:19: 4.1>
SCOPE   7002.219732 sec : VAL [18.3178]
SCOPE   7002.219749 sec : CMD <:GD#>
SCOPE   7002.240649 sec : RES <-13*46:55>
SCOPE   7002.240724 sec : VAL [-13.7819]
DEBUG   7002.240742 sec : CMD: <:pS#>
DEBUG   7002.255794 sec : RES: <East>
SCOPE   7003.257038 sec : CMD <:GR#>
SCOPE   7004.258074 sec : CMD <:GR#>
SCOPE   7005.259371 sec : CMD <:GR#>
SCOPE   7006.260306 sec : CMD <:GR#>
SCOPE   7007.261391 sec : CMD <:GR#>
SCOPE   7008.262453 sec : CMD <:GR#>
SCOPE   7009.263522 sec : CMD <:GR#>
SCOPE   7010.264588 sec : CMD <:GR#>

I stop KStars, and start it again, fire up INDI. The mount responds, then suddenly stops responding ...
SCOPE   25.484658 sec   : CMD <:GR#>
SCOPE   25.506454 sec   : RES <18: 4:57.0>
SCOPE   25.506532 sec   : VAL [18.0825]
SCOPE   25.506549 sec   : CMD <:GD#>
SCOPE   25.527434 sec   : RES <-24*22: 0>
SCOPE   25.527497 sec   : VAL [-24.3667]
DEBUG   25.527538 sec   : CMD: <:pS#>
DEBUG   25.543438 sec   : RES: <East>
SCOPE   26.544536 sec   : CMD <:GR#>
SCOPE   26.567455 sec   : RES <18: 4:57.1>
SCOPE   26.567522 sec   : VAL [18.0825]
SCOPE   26.567535 sec   : CMD <:GD#>
SCOPE   26.588432 sec   : RES <-24*22: 0>
SCOPE   26.588454 sec   : VAL [-24.3667]
DEBUG   26.588495 sec   : CMD: <:pS#>
DEBUG   26.603454 sec   : RES: <East>
SCOPE   27.604553 sec   : CMD <:GR#>
SCOPE   28.605734 sec   : CMD <:GR#>
SCOPE   29.606915 sec   : CMD <:GR#>
SCOPE   30.608086 sec   : CMD <:GR#>
SCOPE   31.609368 sec   : CMD <:GR#>
SCOPE   32.611917 sec   : CMD <:GR#>
SCOPE   33.613110 sec   : CMD <:GR#>
SCOPE   34.614300 sec   : CMD <:GR#>
SCOPE   35.615484 sec   : CMD <:GR#>
SCOPE   36.257941 sec   : <setObjectRA>
SCOPE   36.257980 sec   : CMD <:Sr 18:37.4#>
SCOPE   36.616025 sec   : CMD <:GR#>
SCOPE   37.617186 sec   : CMD <:GR#>
SCOPE   38.617642 sec   : CMD <:GR#>
SCOPE   39.618781 sec   : CMD <:GR#>
SCOPE   40.620084 sec   : CMD <:GR#>
SCOPE   41.621275 sec   : CMD <:GR#>

The only thing I did was connect the laptop to an external booster battery pack after its internal battery was about to run out.

I was suspecting that the power cable and USB cable were overlapping and hence noise or interference. But Why does it work then not work? If it was a USB problem, there would be an error, right?

Any ideas appreciated.


Khalid replied to the topic 'Polar Align Workflow?' in the forum. 6 months ago

1. If there was one, where in Ekos is the user interface for engaging tracking?

All I can found is :RG#, page 43 in 8401 hand controller manual , but it says guiding too, so don't know what it does.

4. I was pointing east, then told the scope to park, then pressed the track button on the hand controller, then the two above scenarios happened (magenta line half outside the picture, and scope in weird position stopped by the mount).

Not sure what else to try.


Khalid created a new topic ' Polar Align Workflow?' in the forum. 6 months ago

On the last clear night, I tried Polar Align Assist twice, but had two different and strange outcomes.

On the first try, PAA completed, then displayed the overlay with the grid, but the magenta colored line was partially outside the picture.

On the second try, PAA rotated the telescope east too far until the tube was stopped by the mount and the hand controller detected current draw on RA and put out an error message.

My mount is a CG5 with the GotoNova Kit. It has encoders on each axis.

So, the questions are:

1. PAA requires tracking to be engaged. Is there a way to do this from KStars/Ekos/INDI? I did not find a way to do so, and have to press the track button on the hand controller.

2. Is it required that before doing PAA, one needs to do a regular align (say to the East) using Plate solving?

3. If a previous regular align is needed, how do we take the scope back to the home position (pointing near Polaris)? Or does one try to polar align when pointing east, and let PAA error out and slew to the North Celestial Pole?

4. If I tell the scope to park using the right click context menu (or the Mount Control), and it does point to NCP, is that sufficient, or does it do something to the mount to disrupt normal operation after? At one point I did park, but the scope would not move afterwards, and I had to power cycle it.

5. Any other hints and tips? Please share them below ...



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