That's also for a long time on my DIY todo list. I am going to use a simple IR sensor to, kind of, measure the temperature of the sky. Clouds are way warmer than a clear sky so in theory it should be fairly easy to detect.
Just recently I did some tests with a simple and cheap IR temperature meter, the same they point at your forehead to check for Covid. Those tests shows a clear difference between a cloud and clear sky. I am not sure if this in the cold wintertime is also the case so more testing has to be done.

Hello
so I already have a weather station with an IR sensor that detects clouds, and it works pretty well.
But it's a little fault for me, because it takes the sky above my observatory, but what can happen is to have the value of "no clouds" but to have clouds in the distance or just want to take a picture of an object.

That's why I was thinking of a camera that counts the number of stars and if all of a sudden the number of stars is more than 10% of the beginning, or you decide to take the pictures of your session, it puts in pose, until a better condition.

Hello constant1462,
take a thermal infrared camera with an all sky lens in front of the camera (e.g. a polished stainless steel ball - or gold plated ball.
You will get a cloud image of the total sky. Clouds are warm, and the cloudless sky is very cold.
The attached photo shows a false color photo. of a polished stainless steel ball with "all sky" in the upper part of the ball. Black is lower than -50degC (no clouds), magenta shows light cirrus clouds around horizon, blue more clouds, and green is the countryside around myself, with me at the center.
Best regards
Frank

@constant1462, counting stars is indeed a better or at least a more 2020 solution. If you can do it by software then you should
You triggered me to do some tests with OpenCV. There are plenty of "object count" examples available.
Thanks for the idea.

Hello gerardvs.
So unfortunately I'm terrible at programming.
Otherwise I'll try to do something about it.
That's why I'm asking if anyone has an idea how to do it or knows a way to do it.
And I'm not very good at English.

Just did a quick test with an old image. I saw many examples but used this one to see how it does on my usually too dark images.
I think it is fairly easy to either analyse the guider images or the real images and do a prediction of cloud coverage once the star-count has dropped significantly.

To be continued.....

You can get the MLX90614 (cloud sensor part of the Weather Radio) in narrow field of view version. The standard part has a 90 degrees FOV but the MLX90614 is also available in 10 or even 5 degrees FOV.

What I am coming at is that a specialized/limited version of the Weather Radio could be built with a narrow FOV MLX90614 that would be put on the same axis and in from of the telescope tube. That could give you a good idea of the cloud cover in the FOV of the telescope, and the standard Weather Radio would give you an idea of the general cloud cover.

Ideally though, an all-sky (thermal?) camera with cloud detection/mapping over the KStars window would be preferred but... that's another story.

Hi Gerardvs
That's exactly what I thought of as an idea, so cool !!

The thing, now, it will be finished to integrate into kstars as we do for weather alerts.

But I think that on will have to add an additional camera, but that's not a problem, otherwise.

In all will I will wait impatiently to hear from you.

See you soon
Christophe

So I have the standard version of my weather station, by the way I didn't even know there was another angle.

I am not sure you can get the narrow FOV parts with evaluation boards like the Adafruit or DFRobot ones but they are available as discrete parts that you could use if you have soldering skills. Unless they are surface mounted on the evaluation boards, I am quite certain that one could replace the standard part with the narrow FOV one fairly easily.

If you are interested/curious, you can look at the Melexis datasheet for the MLX90614, www.melexis.com/en/documents/documentati...s/datasheet-mlx90614 .

I just found this interesting paper that could be relevant to what you want to do. It uses an all-sky camera (180 degree FOV) to estimate and map cloud cover for the observation of Cherenkov photons.

s3.cern.ch/inspire-prod-files-9/98f5d2c8...5cadd2963404c8ae5eec

Hello
So indeed it looks good, but I admit not having understood all because my English is not as good as before.
Does he put a simple all sky style camera or is it an IR camera?

So the most, it is if you manage to make a correspondence between what the camera detects and manage to say that in 10min it will be covered in kstars.

But I think it's more complicated to set up than a star-counting camera, right?