SQM LE (Ethernet) Reader

Request for Unihedron SQM-LE Reader integration in Voyager.

This device is sharing data via TCP.
Full instruction manual here: http://www.unihedron.com/projects/darksky/cd/SQM-LE/SQM-LE_Users_manual.pdf

I have 2 devices available for test.


OK, request accepted … will be in the next daily build for testing.
I think to implements only the RX command for retrieve actual data, manage is in charge to original software.

All the best

I’m starting to implements SQM Reader protocol … but i stopped it … a question born ?
When i have data how it can be used ??? For an AP is only info and nothing else !!!
What is utility of this reading in automation other to understand the quality of your sky and save it on the FIT ?

Make sense to have a dragscript new block wich wait for SQM value or not ? Or what else operations must be implemented in Voyager related to SQM reading ?

Hi, I was thinking to have a similar logic as “Cloud Sensor” for Weather.

You can add a small connection window into “Weather” Tab and values for:
Don’t Care : Check Box , save the value into FIT file only.
OK / Resume > : Numeric field, XX.XX (19.61)
Suspend < : Numeric field, XX.XX (19.60)
EXIT < : Numeric field, XX.XX (12.00) Hey, the night is over! :scream:

Im my case I would like to set 19.6 as acceptable value, over 19.6 is OK, under 19.6 Suspend.

Of course the UI window is not mandatory, I can do that via DragScript, I have to handle exceptions like:
Half/Full moon and Ha filter, in this case I will set my session with “Don’t Care” value, the SQM is low but I will continue my session because the narrowband filter.

Let me know if it make sense.

I think this is a drastic decision to relate session to SQM value. For my experience the SQM value is not related to real quality of sky. In anycase sounds good … i’ll procede implementing your suggestion.


If my request doesn’t make sense i can accept it, don’t waste time with it, there are many other important developments in progress to complete before this one.
Saving the value into the FIT file is enough.

A small “SQM Value” box into Weather Status Window (Main UI), under Humidity box, will be appreciated. Unfortunately I have no idea what is the SQM icon …

Have a nice weekend

No wast of time absolutely :grinning:

I’m new here coming from SGP and just registered so I can ask if this has been implemented. I’m also curious about getting the SQM readings into my FITs headers (SGP does this, as well as other data from the Boltwood file using the ascom observing conditions hub). Triggering on too bright a SQM reading would be a good safety-net too for suspending the session.


Welcome Gabe,

we are talking about introducing SQM reading. WE can do this. Booltwood data is reading directly without ASCOM. I can put also on the FIT. I added this in the todo list.

All the best

1 Like

this could be damn cool, and would incrase my “spend more wish list” :sweat_smile:

I’ll do it … i promised to Kristjan to many time ago now… :frowning:

Hi Leonardo,

A more general solution would be to support the ASCOM Observing Conditions interface, and place any data available into the FITS header. I would find this a big step forward.

Thank you for considering this proposal.


1 Like

I’ll do in this way. Thanks Tom.

All the best

1 Like

The inclusion of the SQM data is a really big win for me, thanks very much! One last little bow to put onto the package, if possible … just as you’re going to be putting in a facility to get the Temperature property from the Focuser interface and put that into a variable that can be acted upon in DragScript, the ability to query the SQM value and put that into a variable would also be really valuable.

Why? Well, SQM values greatly affect the end result for stacking, enough that I generally sort exposures by as little as a .1 difference and due to object extinction there are some SQM values that below which it’s just not worth it to image at. During the evening SQM values will vary by as much as .75 if you get some high atmospheric clouds that don’t show up on a cloud detector (since they are high enough that they don’t reflect IR) but do reflect surface light or moonlight, increasing skyfog.

If I could have a way to measure the SQM at the beginning of an image exposure and compare that to a minimum value it would save me from wasting time taking an exposure that would get tossed in the morning anyway …

Just a thought, thanks!

1 Like

Sure Craig i’ll add it … no problems.

All the best

1 Like
1 Like

well… now i have to buy it -.-

It’s well worth it … the USB interface works without problem, the SQM meter itself is a very narrow field (about 30’) so if you mount it on the OTA nose it will give a reading of the the object and not “the sky” which is valuable for high clouds over some of the sky …


Interesting solution … i never heard about this …