A Fully Automated Imaging Observatory - WIP

[steppenwolf]

The new automated dome has just passed its first test (tracking for a long period of time) with flying colours. The Sun was shining in West Sussex today, so I set the dome to track it (slaving the EQASCOM simulator) via CCD Commander and a faultless 7 hour track ensued - this also had the advantage of allowing the solar charging panel to get the best angle on the Sun to give the aperture slit battery its first free top-up!

I learnt a valuable lesson last night in that it is possible to have a conflict between POTH and MaxIm DL if 'Slave Dome to Scope' is set in MaxIm's Dome control window. This manifested itself by the mount ('telescope') parking correctly, the dome parking momentarily at 180° and then slewing to match the position of the parked mount at 0° !! Turning off 'Slave Dome to Scope' in MaxIm DL resolved the issue.

Tests using the automated aperture slit were perfect.

I've also spent time today finalising the geometry calculations for mount offsets within the dome as getting these right will be key to accurate aperture slit placement to match the non-linear positioning of the GEM.

UPDATED SPREADSHEET 20/05/15

[skybadger]

I don't understand why you need those offsets. Poth and maxim will both handle them internally.

Mike

[steppenwolf]

I don't understand why you need those offsets. Poth and maxim will both handle them internally.

Hi Mike, I need to calculate those offsets to input the figures into POTH and MaxIm so that they can handle them internally?

From the POTH help file:-

POTH OFFSETS

If you are using POTH, you have to enter correctly the "dome geometry" in the setup. Indeed despite the fact you have a fork mount, you have to enter the "scope position" which is the position of intersection between declination and right ascension axes :

Scope position E/W (East / West)

Scope position N/S  (North / South)

Scope position U/D  (up or down in respect to the base of the dome hemisphere)

For a fork mount, you enter 0 for "GEM axis Offset"

To get correct dome Azimuth calculation from Right Ascension and Declination, you have to provide precise dome geometry data.

[Earl]

making sure these offsets are the same accross all the settings is key too, as with all astronomy stuff there are no standards and applications all do it differently. its a nasue.

[steppenwolf]

making sure these offsets are the same accross all the settings is key too

That's quite right Earl and one of the reasons that I have included Metric and Imperial units in the spreadsheet - POTH is Metric, MaxIm DL is Imperial.

[skybadger]

Yes but those offsets are a one-time entry only based on the location of the mount with respect to the centre of the dome and the height of the mount with respect to the aperture base height.

M

[steppenwolf]

Yes but those offsets are a one-time entry only based on the location of the mount with respect to the centre of the dome and the height of the mount with respect to the aperture base height.

Absolutely right but I needed to get those offsets for the one-time entry in the first place and that is what the spreadsheet does! This spreadsheet is not intended to be volatile, it simply formalises the data, calculates the offset of the intersection of the RA and Dec axes and corrects for the actual pier position, all for that one time entry.

[Earl]

Steve what settin do you have the knob on the dome rotation box set to?

[steppenwolf]

Hi Earl, with the latest version (which I have) there have been various changes- photos to follow soon - and one of those changes is that the speed controller is no longer connected even though it is physically there so I am afraid that I am unable to answer your question meaningfully! Sent from my iPhone from somewhere dark .....

[steppenwolf]

Skybadger, it has just occurred to me that you may be scratching your head and wondering why I am using a spreadsheet to get these values rather than a ruler? If you could see the shape of a Mesu 200, you'd understand.

Sent from my iPhone from somewhere dark .....

[skybadger]

Ah, I think that is probably the bit I am missing. Ruler and tape measure did mine. Then a bit of fine tuning.

Regs

Mike

[steppenwolf]

Hi Mike, The design of the Mesu doesn't lend itself to measuring with a ruler as the RA and Dec axes are large and thick platters. Now, if it had been my EQ6, I could have easily measured that! I rather enjoyed re-learning my old school trigonometry though and the data and how it was derived may be of interest to other Mesu users following this automation path. There is an error that I will correct when I get the time - the N/S figure should be positive not negative. Corrected 20/05/15.

Sent from my iPhone from somewhere dark .....

[mhard26339]

Looking good Steve, I particularly liked the period with Gary and Dave's head bobbing up and down from within the dome walls.  Did you see my last post re remote operation, I had the chain snap when I was operating from Spain!! the only way I knew it had gone was that I always monitor operations on an IP camera in the dome; Maxim would have shown the shutter closed and I would have thought all was well. I have also added an Oculus to the cloud sensor to monitor the weather. Lessons learned!! which also include having a spare set of keys with a reliable neighbour who can close the shutter manually; Gary supplied the spares FOC

Thanks for the IM re security, will ring you when I get back to UK.

Regards

Mike

[steppenwolf]

Hi Mike,

Sorry to hear about the chain snapping - that is bad news with you being so physically remote! I will be using the Lesvedome system (I think yours is the Shelyak system?) so it *could* be that there is a feedback signal to indicate that the end-stop switch has activated - I will check this out as it is a significant feature if it exists. One of the first things that I am going to do after I have completed the dome installation proper will be to silicone spray the chain links.

I have now got the mains AC power connected to the observatory but I am still making small tweaks to the observatory itself before I start installing my astronomy gear - door détentes, security system, a cable entry point for the cloud detector etc. are all under way.

[Earl]

Steve I may of missed it but have you documented your ascom setup so to speak?

[steppenwolf]

I haven't as yet documented my ASCOM setup as I am still assembling the system and completing the observatory installation itself. However, I am using POTH to connect to both the dome controller and the mount. Is there any specific information that would help you?

[Earl]

I haven't as yet documented my ASCOM setup as I am still assembling the system and completing the observatory installation itself. However, I am using POTH to connect to both the dome controller and the mount. Is there any specific information that would help you?

when you get round to it a flow chart of sorts and mayeb some reasing to why certain routes would be helpful overall, getting it all to talk reliably is an ongoing issue for me atm.

[steppenwolf]

I'll be happy to do so, Earl. I'll be in touch as soon as I have the system fully proven.

[steppenwolf]

ADDITIONAL NOTE 4 - Images of the power and control installation in the new dome for those interested in this project:-

The new power board is installed and commissioned with zero faults at switch-on!

New Observatory with Solar Charger

Electric Power Board and Dome Control Unit

My original observatory had a series of extension cables on extension cables as the system grew but the new installation has been custom designed for purpose and has its own consumer unit with RCD rather then relying on an external RCD feed from a greenhouse.

Items hatched out are part of the extensive intrusion detection and lock system.

Azimuth Control Unit

This is the very latest design from Pulsar and utilises a single friction drive with a precision pinch wheel on the smooth reverse of the dome flange to ensure little risk of slippage - it works extremely smoothly. An encoder keeps track of where the dome aperture is pointing.

Azimuth Motor Drive

Aperture Controller

The aperture controller is powered by an 18 amp-hour battery charged by a solar panel.This unit is controlled via the azimuth control system using a RF link.

Aperture Drive Chain

A nylon chain is used to open and close the aperture and this works very well but it did require silicone lubrication to make it run quietly and it is very sensitive to getting the tension right - however, I am now on top of that and have got it operating perfectly.

[steppenwolf]

Today I completed the installation of the hardware in the new observatory and ran the first set of tests on the system.

The first test was simple yet key to the success of the project - confirming the 'slaving' of the dome aperture position to the telescope's pointing. I was delighted to discover that the telescope points directly through the centre of the aperture slit at both sides of the meridian.

The second test was to confirm software control of the automatic Flat-Flap using one of the digital outputs from the LesveDome control board. I had to modify a couple of small VBscripts (a pretty new experience for me!) to close and open the flap and once I got the switch number right (no correlation to the actual digital channel number ) I was delighted to see it working perfectly

VBSCRIPT TO CLOSE THE FLAT-FLAP USING CHANNEL #7

driverID = "ASCOM.LesveDomeNet.Switch"
set o = CreateObject(driverID)
o.Connected = True
o.SetSwitch 3, True

WScript.Sleep 60 * 60

VBSCRIPT TO OPEN THE FLAT-FLAP USING CHANNEL #7

driverID = "ASCOM.LesveDomeNet.Switch"
set o = CreateObject(driverID)
o.Connected = True
o.SetSwitch 3, False

[steppenwolf]

This installation phase of this project is now completed successfully so there will not be any further updates on that aspect. Thanks for reading so far!

PC Installed

AAG Cloud/Rain/Daylight Sensor Installed

[steppenwolf]

ADDITIONAL NOTE 5 - Software Implementation:-

With all the hardware now installed, it is time to get to grips with the software and getting each component to 'talk' as one!

The first issue is actually a hardware one - remembering to undo the dome locks but software comes to the rescue here.

The second issue is the sequence in which the various pieces of software must be initialised - anyone remember 'batch files'? Here are the batch files and scripts that I use to get it all started:-

Start FocusMax, Cartes du Ciel, AAG CloudWatcher and finally CCD Commander

VBScript to run batch file minimized

CreateObject("Wscript.Shell").Run "start_CCDcommander_and_AAG.bat", 0, True

The batch file itself

:Pause to display warning message
echo off
CLS
:*** WARNING - UNDO DOME LOCKS ***
undo_locks.vbs
: Run FocusMax
start "" "C:\Program Files\FocusMax\FocusMax.exe
: Run Cartes Du Ciel
start "" "C:\Program Files\Ciel\skychart.exe
: Start AAG_CloudWatcher executable
cd\AAG Cloudwatcher
autostart_CloudWatcher.vbs
: Start CCD Commander and wait for it to close
start /wait "" "C:\ccd commander\CCDCommander.exe
: Run AAG_CloudWatcher executable closedown after CCD Commander closes
close_AAG_CloudWatcher.bat
:Exit this batch file
exit

undo_locks.vbs

MsgBox "*** WARNING - UNDO DOME LOCKS ***"

autostart_CloudWatcher.vbs

Dim oCW
set oCW = CreateObject("AAG_CloudWatcher.CloudWatcher")
oCW.Device_Start()
oCW.RecordStart False
Set oCW=nothing

close_AAG_CloudWatcher.bat (also closes FocusMax)

autoclose_CloudWatcher.vbs
tskill AAG_CloudWatcher
: Close FocusMax
tskill FocusMax

I also discovered that it is necessary to set FocusMax to automatically connect to the focuser (default is to not connect)

Try as I might, I cannot get Cartes du Ciel to automatically connect to the mount or to disconnect and close automatically. For the latter, I have tried the following with no success:-

Method 1 (fail)

: Close Cartes Du Ciel - under development

tskill skychart.exe

Method 2 (fail)

: Close Cartes Du Ciel - under development
cd\PSkill Tools\PSTools
PSKILL skychart.exe

Anyone have any suggestions for this?

[Earl]

Steve I dont bother with the dome locks had some strong wind and its not been an issue. Unless your using them for security purposes?

[Earl]

oh do you know a way to autostart the cloud sensor un reboot, it will go in the startup folder but still needs to be clicked start to go. is there a switch i can add to the command line?

[steppenwolf]

oh do you know a way to autostart the cloud sensor un reboot, it will go in the startup folder but still needs to be clicked start to go

Yes there is, my VBScript above starts the program and the logging automatically for you.