Chris Rowland replied to the topic 'focus and Polar align "issues"' in the forum. yesterday

wvreeven wrote: I agree that it would be nice to synchronize the home/park setting and another complication may be that not all mounts support this. I, for instance, use my SW HEQ5 without HC and I am not sure if the home position is stored on the mount or the HC. I am not saying that this therefore should not be implemented but rather that this needs to be done with care so not to break the current implementation in other telescope drivers.

Err, that's what I just said.


Chris Rowland replied to the topic 'focus and Polar align "issues"' in the forum. yesterday

Yes, you can use the hand control buttons. On the Celestron if you press one button, then press the opposite one as well you get a full speed slew.

As for the Celestron Home and INDI Park I would like to make them the same. The control for this exists in the protocol for the current HCs. One snag is that the INDI park handling is embedded into the base part of the driver and it may be difficult to extract it without upsetting everyone else.


Chris Rowland replied to the topic 'Mount starts to move even if it's parked..' in the forum. yesterday

Isn't the problem really that the mount driver is broken? if it's parked it should not respond to any move command.


Chris Rowland replied to the topic 'focus and Polar align "issues"' in the forum. yesterday

For the movement in Ra being inconsistent I think this is because when you are close to the pole Ra is a very poor measure. It would be better for the software to be aware of the movement rate in degrees per second and use a timer to do the move. As a user, set the manual move option and move by hand the amount you want.


Dynamically correcting for drift caused by polar alignment error will only be partially successful because it can't cope with the field rotation that the polar align error generates. Fortunately this rotation is fairly small over most of the sky.

An alternative polar aligning method is already available, the Ekos Polar Align Assistant. This rotates the mount about the Ra axis, taking and solving three images. These images are all located on a circle the centre of which is the Ra axis pointing direction. Once you know that it should be possible to define the corrections needed to polar align the mount and apply these by centering a convienient star.

There's a bit of devilment in the details because the polar align error is defined in the Ra/Dec coordinate system and it needs to be transformed to the Alt Az coordinate system because those are the axes about which the mount is rotated to do the polar aligning. It's remarkbly difficult to get this transform correct.
Also the current PAA implementation assumes that the mont is pointed close to the pole. I don't think that is essential and hope to have a go at trying to get this to work without that constraint.

Toshimo Taki's Matrix method is still available -



Chris Rowland replied to the topic 'Building one driver only' in the forum. 2 days ago

Thanks for the help, this is what i ended up with, it will update the sources from my personal repositiory, buid and distribute.
Lifted the sudo check from AstroPi3, thanks.
There are a couple of reads that give me a chance to review what's going on, they can be commented out of course.


if [ "$(whoami)" != "root" ]; then
        echo "Please run this script with sudo due to the fact that it must do a number of sudo tasks.  Exiting now."
        exit 1
elif [ -z "$BASH_VERSION" ]; then
        echo "Please run this script in a BASH shell because it is a script written using BASH commands.  Exiting now."
        exit 1
        echo "You are running BASH $BASH_VERSION as the root user."

export USERHOME=$(sudo -u $SUDO_USER -H bash -c 'echo $HOME')

echo "kill indi server because it seems to upset things"
pkill indiserver

echo "get the latest sources"
cd $USERHOME/Projects/indi
git pull

# set the build directory
cd $USERHOME/Projects/indi-build

# read -p "run cmake"

# read -p "$ make indi_celestron_gps"
make indi_celestron_gps

read -p "distribute the required files"

sudo cp -av indi_celestron_gps /usr/bin
sudo cp -av* /usr/lib
read -p "update the configuration"
sudo ldconfig -v /usr/lib


Chris Rowland replied to the topic 'Celestron hybernation mode' in the forum. 4 days ago


Any NexStar Plus HC is fine, it doesn't matter if it has a RJ11 or USB connector on the base of the HC.
To check look in the INDI Control Panel, the Celestron GPS tab. The Mount Info tab should show the Model and HC version. What are they?
And the Options tab should show Hibernate with the Enable button highlighted.

Then clicking on Park(ed) in the INDI Control Panel Main Control tab OR the Park button on the EKOS Mount tab will park the mount AND Hibernate it when the park has completed. You can disconnect and power cycle the mount.
Unpark will then wake the mount up and unpark it.
The mount info will show what's happening, this is what it looks like for my tests:

2020-01-17T16:14:01: [INFO] Slew complete, tracking...
2020-01-17T16:13:26: [INFO] Slewing to JNOW RA 0:11:33 - DEC 29:06:30
2020-01-17T16:13:17: [INFO] Mount is unparked.
2020-01-17T16:13:17: [INFO] Waking up mount...
2020-01-17T16:13:15: [INFO] Observer location updated: Longitude (-0.717) Latitude (51.6)
2020-01-17T16:13:14: [INFO] Device configuration saved.
2020-01-17T16:13:14: [INFO] Saving device configuration...
2020-01-17T16:13:14: [INFO] Device configuration saved.
2020-01-17T16:13:14: [INFO] Saving device configuration...
2020-01-17T16:13:14: [WARNING] Mount is NOT aligned. You must align the mount first before you can use it. Disconnect, align the mount, and reconnect again.
2020-01-17T16:13:14: [INFO] Mount UTC offset is 0.00. UTC time is 2020-01-17T16:12:50
2020-01-17T16:13:14: [INFO] Mount is parked.
2020-01-17T16:13:14: [INFO] Mount tracking is off.
2020-01-17T16:13:12: [INFO] Mount model: AVX
2020-01-17T16:13:12: [INFO] Controller version: 5.31
2020-01-17T16:13:11: [INFO] Celestron GPS is online.
*** Power on and Connect

*** Disconnect and power off
2020-01-17T16:12:55: [INFO] Celestron GPS is offline.
2020-01-17T16:12:48: [INFO] Mount hibernated. Please disconnect now and turn off your mount.
2020-01-17T16:12:48: [INFO] Hibernating mount...
2020-01-17T16:12:48: [INFO] Mount is parked.
2020-01-17T16:12:13: [INFO] Parking is in progress...
2020-01-17T16:11:17: [INFO] Slew complete, tracking...
2020-01-17T16:10:42: [INFO] Slewing to JNOW RA 0:10:49 - DEC 27:56:39

Hope that helps, maybe it's too easy. There are no hibernate and wake up controls because they are not needed. Park does the hibernate and unpark does the wake up.



Chris Rowland replied to the topic 'Celestron hybernation mode' in the forum. 4 days ago

Yes, you need a NexStar Plus HC to get hibernate and wake up using Ekos. The earlier HCs had hibernate and wake up in the HC but it was not available remotely until the NexStar Plus HC.


Chris Rowland created a new topic ' Building one driver only' in the forum. 5 days ago

I'm in the process of updating a driver and I need to install and run my local copy on a Pi Zero running Raspbian.

I'm developing on a Pi 4 and I've committed and pushed to my own repository.

I can clone this to the Pi Zero, in ~/Projects/indi

I can build following the process in AstroPi3 Raspbian but it takes for ever and I only want the indi server and my driver.
the build process is:
cmake -DCMAKE_INSTALL_PREFIX=/usr -DCMAKE_BUILD_TYPE=RelWithDebInfo ~/Projects/indi
sudo make install

I've tried:
make indi_celestron_gps

and this seems to just build indi_celestron_gps and it's dependencies but:

sudo make install

then builds all the things not built in the first run of make and

sudo make install indi_celestron_gps

seems to do the same.

would only build the celestron driver and it's dependencies?
Would I need to do something with the make install step?



Chris Rowland replied to the topic 'Problem with polar alignment in southern hemisphere?' in the forum. 5 days ago

Just a thought...
Moving to the Southern hemisphere has the effect of rotating the images by 180 degrees and maybe the direction vector is also rotated.
Another thing that rotates the image is a pier flip and maybe it would be different if the mount were on the other side of the pier when the images are collected.
That should be easy to test.

Having a diagonal (actually an odd number of reflections) in the image chain will flip the image and that could also have an effect.

I can't test because I can't see the pole from where I usually set up and the PAA assumes you are looking at the pole. I don't think that's essential, the three images could be any distance from the pole. It's on my list of thigs to try, but it's a long list and it's very cloudy in the UK.