All Sky Camera

[Gina]

http://www.mouser.com/ds/2/115/74LVC1G17-80223.pdf

This is the one I use for reset delay in my arduino compatible projects.

It's €0.24 in single quantities

/per

Thank you Per - looks just the job   Now to see if I can find it in this country

[Gina]

Somewhat dearer in this country   This on ebay.

[Gina]

Ordered a couple.  Would have preferred DIP to SMD but not available.

Project now on hold until some parts arrive.  OK... next project

[ollypenrice]

Olly is actually wrong about who can see our new allsky. http://grinderphoto.se/Full_etoile.jpg

/per

I was talking about the tree, not the Allsky!   The robot shed is on higher ground than the rest.

Olly

[skybadger]

Gina, what is the cap for ?.Inrush current ?

Shouldn't there also be a snubbed diode across the solenoid too?

M.

[perfrej]

Definitely a diode! Always! An Arduino will make a nice trip to lala-land until reset when that solenoid fires off a spike of reverse current

/p

[Gina]

The full circuit has a diode across the solenoid.  The capacitor provides a high current pulse to make the solenoid pull in then the series resistor reduces the holding current to a value that doesn't overheat the solenoid.

I tried to upload a circuit diagram in JPG format but the upload isn't working ATM

[Gina]

Here's the op amp Schmitt trigger version of the circuit diagram with modified values for the electrolytic capacitor and series resistor.

[Gina]

 Alternative version with Schmitt trigger chip.  LM7805 +5v voltage regulator needed to drop supply voltage for the Schmitt trigger chip.  So not as simple as it first seems.

[perfrej]

If you want to run it off of 12V just use a CD40106 instead.

/per

[Gina]

If you want to run it off of 12V just use a CD40106 instead.

/per

Yes, could do   That would be a bit simpler

[Grinde]

The Robots, as I call them (the group running robotic scopes from my place) have just installed one of these. It has rather curtailed my style. I used to like going up onto the house roof at night, declaring independence, announcing my new set of postage stamps, making indiscrete references to Joan of Arc and hurling abuse at passing enemy aircraft. (Surprising how many there are.) I now have to do this from within the observatory to avoid detection...

lly

Don't fight fight us Olly, resistance is futile! // The Les Granges Robots

(attaching a photo of our robotic setup, we're blending right in at Olly's backyard.)

Sincerely sorry for cramping your style, but the Allsky-camera has a mask-feature, so we can look into masking out your roof-top.

Gina, that's an awesome project you got going!

When the camera is up and running, I'd recommend having a look at the allsky-software from Moonglowtech, http://www.moonglowtech.com/products/AllSkyCam/Software.shtml (the brand we're using at Olly's), the program is really packed with nice features as ftp-upload, periodic movie-generation and so on... I'm sure you'll write your own software for it, but the trial-version may be worth a peek for inspiration. 

Keep it up & merry xmas

Jonas

[Gina]

Thank you Jonas   That software looks very interesting

I wish you a Merry Christmas too

[Gina]

Think I shall go for the CD40106 option and have ordered same.  Soonest delivery looks like next Monday though so won't get the camera in full operation until after them.  I guess I could rig the camera up with wired remote control of the shutter though.  Still have the shutter to make yet - new design needed - and need to find my Baader film offcuts

[ollypenrice]

Don't fight fight us Olly, resistance is futile! // The Les Granges Robots

(attaching a photo of our robotic setup, we're blending right in at Olly's backyard.)

Sincerely sorry for cramping your style, but the Allsky-camera has a mask-feature, so we can look into masking out your roof-top.

Gina, that's an awesome project you got going!

When the camera is up and running, I'd recommend having a look at the allsky-software from Moonglowtech, http://www.moonglowtech.com/products/AllSkyCam/Software.shtml (the brand we're using at Olly's), the program is really packed with nice features as ftp-upload, periodic movie-generation and so on... I'm sure you'll write your own software for it, but the trial-version may be worth a peek for inspiration. 

Keep it up & merry xmas

Jonas

Jonas, my man, don't you have any work to do? Don't tell me you knocked this one up on your mobile while flying in the dark over an orphanage???

Have a good Christmas!

Olly

[perfrej]

Jonas, if you're done with my TEC, can I have it back? I know the unguided tests on that mount didn't turn out too well so I'm thinking of putting it back on my GM2000HPS on the Humvee. And Olly, if you move the Panda I can back the Humvee into the obsy again where it belongs - once Jonas has backed that aggressive mount of his out.

/per

[Gina]

My CD40106 order came this morning so I can move on

I've added an adjuster for the closed shutter position and while at it, a pin to take the end of the spring.  SketchUp plus 3D printer make these things easy

Here are some photos.  I've yet to add some Baader solar film to the shutter but without it you can set up the shutter position.

Shutter closed - solar film will cover the hole in the finished version

Shutter open

Shutter position adjuster and spring peg

[Gina]

May tackle the circuit for controlling the shutter this evening.  Need to find the LDRs and Baader film before I can set it up outside.  Mind you, there's no sun forecast for tomorrow so I guess I could set it up without Baader film.  I'll see

[Gina]

Solend control circuit board layout.  I'm going to use three 22 ohm 1W resistors rather than the 10W 68 ohm resistor which is too big to go in the case.  I shall fit these around the edge of the dome to help with dew heating.

[Gina]

External connections to circuit board.

[Gina]

Although I will be using the QHY5 for the time being, I am looking at buying an ASI120 camera in the future.  I'm wondering whether to go for the mono or the colour version.  I imagine the mono would be more sensitive and show the stars better but OTOH the colour version might show the star colours and would be better for daytime use (if it's possible).   There is also the possibility that I might use a colour one for planetary imaging.

Any opinions most welcome   Thank you

[Gina]

Decided it's high time I had another look at this project  

The main reason for not doing anything to it apart from concentrating on other projects is the day/night problem.  I know I've developed a shutter system operated by a solenoid but I'm just not happy with it - too complicated and I'm not completely sure of the reliability.  I guess I've been waiting until I have the funds to buy an ASI120 which they say isn't affected by having the full power of the sun on the sensor.

Now I have an imaging system working properly, I can spare some time on other projects.  And with it being galaxy season there is no pressure on shorter FL imaging systems - the MN190 with 460EX mono CCD camera and FW is the ideal setup for galaxies.  With the better weather I've been working on the observatory preparing for remote controlled motorised roll off roof and wall flap/window. 

I already do unattended imaging watching the results remotely in the house and while the PHD guiding display gives a good indication of sky conditions where I'm imaging, it would be nice to be able to see what the rest of the sky is like so that I could be better prepared for incoming clouds (or worse).

[Gina]

I assembled the casing and tried the shutter operation and it isn't moving enough to clear the sensor fully.  No good, this is rubbish   I think I would do better using a servo motor and an Arduino   Probably more reliable and if it were to fail I'm only risking a QHY5

Also, if I used an Arduino I could add remote focussing.  The present manual system is rather awkward and also means I can't fully seal the casing.

[Gina]

I have several little servo motors somewhere in one or more of a dozen or more assorted boxes waiting to be sorted out   Just looked up Arduino servo control and it could hardly be simpler   Just the servo library and a couple of simple instructions.  eg. this  I could probably use another servo motor for focussing (stepper motor would be overkill ).

[Gina]

Been looking into remote focussing.  In particular the mechanics.  The lens is focussed with a small lever on the side that moves somewhat less than 90 degrees.  I'm going to try a ring with a notch to engage with the lever and then see about rotating the ring.

I plan to use the dome without its attachment ring and to print a tube to fit inside which can then be glued in place to provide a seal.

Here's photos of the dome on its own and the lens showing the control levers followed by a diagram of the focus ring.