Gina's DIY All Sky Camera - Mark3 - with QHY5L-II-C

[Horwig]

It is a genuine Nano is it? I'm using a Nano clone, and I had to use an older driver, the current FTDI driver is designod not to see clones. cdm 2.08.30 is the one that works for me.

Huw

[Gina]

It worked for a while then stopped responding.

Got problems with EZPlanetary now too   Keeps locking up after an image save then needs Windows Task Manager applied several times with End Task to shut it down.  I'll have to try reinstalling it.  Pity, it was good while it lasted!

[Horwig]

My ezp has a habit of locking out if I try to stop a recording, and every so often, for no reason at all.

usually it then shows black when you re connect to the camera, but dis connecting, and re connecting the usb usually brings it back.

Not the best piece of software me thinks

Huw

[Gina]

I've found one of my recent Nano purchases and this has the 640 type USB-Serial chip which is the latest and replaces the FTDI chip.  These overcome a couple of problems with the FTDI chip.  I have uploaded my sketch to it and it's working fine

Still running EZPlanetary but not using the image or video recording facility ATM.  I'm concentrating on the casing etc.  I tried putting the camera plus lens on test pipe out of the window last night and it had dewed up in a minute or two.  I got a couple of rather poor captures - 60s and 120s.  It's pointless trying without a heated dome with the heavy dew we're getting at night currently. 

Here's a screenshot this morning with the test rig.

[Gina]

Printing case parts.

This is a test top part to check dimensions

As above with dome added.

Printing the bottom part of the case.

[Gina]

I've decided the top and body of the case can be combined.  This will then fit over the bottom part which is a push fit on the pipe.  I'm currently unblocking the printer nozzle with acetone.  Meanwhile, here are a couple of screenshots of the top & body model in SketchUp.  The casing is designed to just accomodate all the parts.  The oval cylindrical shape saves plastic and reduces windage.

[Gina]

This photo gives a rough idea of how the parts go together.  Of course, the top will be straight and not crooked as seen here

[DrRobin]

Gina,

I am not getting any misting up inside my dome, but I did go to some lengths to seal it up with a couple of home made neoprene gaskets. I don't use a heater, curiously that might just add to the problem. The amount of moisture that can be held in air is dependant on the temperature, the higher the temperature the more moisture. Where hot air comes in to contact with a cold surface, it gives up its moisture and this forms as dew. Clear domes are always colder so dew forms on these, not helped as they are at the top.

The best way to avoid dew, especially inside is to keep it sealed (air tight) and at around the same temperature as the outside air. Of course if it is just very wet outside and dew is forming on the outside then no amount of heat inside is likely to shift it.

On the software front I have been looking for something which will run fully automated. I use AstroVideo, which has a script language, but I can't do everything, so have combined some AutoIt scripts to complete the control. I am thinking of writing a bespoke app to capture stills and upload them to my website as I haven't been able to find a package with everything I want. Here is my list of requirements

Schedule taking of stills every x minutes;

Apply dark frame subtraction;

Monitor the histogram and use a routing for auto-exposure even over 60 seconds or more;

FTP to a server;

Add custom overlays, E.g. The constellation names and lines;

Add N, S, E, W marks;

Meteor detection.

The only problem is that it has been a few years since I did any Windows programming (other than scripts) and I am not sure how long it would take me to get a working prototype, or how user friendly it would be.

Robin

[Gina]

The only misting I got with my dome was on the outside.  Using a dew heater cured it.  That was with the Mark 2 version - now I'm doing the same for the Mark 3 with the new camera.  Sealing the ASC against damp should not be a problem.  I was going to include the humidity sensor in the case but decided I would rather keep damp out of the ASC case and put the DHT22 digital humidity and temperature sensor in a separate little Stevenson Screen which I already have for my weather station.

If you write your software in a version of C you should be able to compile on any platform.  The same applies to Python if your app isn't speed critical.  I'm hoping to have my ASC running totally in Linux but currently Windows has the edge.  I would like to get back into writing all my own software again but my poor old brain is not what it was

[Gina]

An hour and a half to go till my ASC body is finished

Just replaced the dead Nano with a socket to make future replacements easier.  I had a thought though... (yes - really )  Use serial connection and a  USB-Serial chip near the laptop.  Then I could use just the ATmega 328 chip.  Or perhaps recover dead Nanos.

[Gina]

Body finished and seems good   Have a problem with my circuit board though.  Something is drawing excess current from the 5v o/p it seems.  Red LED is dim and no device detected.  Nano unplugged from board and it works fine.  A faultfinding we wiil go...

[Gina]

Couple of photos of complete casing.

[Gina]

Well, I can't find the problem with the circuit so no remote control available tonight.  However, I have fitted the camera and lens in the casing with dome and I've also fitted the dew heater with cable so I can run it off a fixed 5v or maybe bench PSU and variable voltage.  So I should be able to avoid dew.  The only problem is that I had to focus with the dome off and now with the dome on the focus is a bit off.  Hopefully I'll be able to sort it all out tomorrow.

[Gina]

Screenshots of captures.

[Gina]

I have now gone right through the wiring and component placing on my circuit board plus carefully inspected for solder bridges and I can find nothing wrong!  BUT when I plug the Nano into its socket it loses power   The only thing I can think of is to rebuild it on another piece of stripboard.  It would be a chance to improve the layout perhaps too, in line with differences from the original requirements.  To be more certain of getting things right I shall go through the layout in detail.  Now working on it...

Arduino Nano.

ULN2003A Darlington Driver x7.   4 of 7 parts used to drive the stepper motor for focussing - other 3 not used.

Current Circuit Diagram.  The Arduino pin numbers can be changed to optimise the layout - just a matter of altering the sketch.

[RLWP]

Those images look significantly better than your previous camera, Gina

Richard

[Gina]

Thank you Colour makes a big difference IMO - not sure about the performance on stars yet though.

[Gina]

Circuit Layout.

[Gina]

No it's not working yet

Still having problems with EZPlanetary.  Tried reinstalling it wit and without deleting user settings.  Tried installing it in a different directory.  Just the same - still locks out some of the controls if I try to RECord.  Don't know what else to try other than reinstalling Win 7 and I don't fancy doing that   Got the laptop secondhand with no installation disk.  The copy of Windows is registered though - it's all legitimate.

Could anyone suggest a Linux app that will do 20us to 60s exposures, colour, AVI recording, etc. ?  EZPlanetary worked well for a while - now it's impossible except for viewing and I'm not staying up all night doing screenshots!

Maybe I'm getting stale and missing something   Maybe I should give this project a rest for a while...

[Gina]

Been letting this "ferment" in my brain...  I have two main problems :-

1. The software I'm using has stopped working properly.  Until I sort that out I'll use oacapture with it's limits of 1ms to 10s exposure range.
2. Hardware not working from Arduino Nano. 

I guess that's just about the whole caboodle - software and hardware

If I can sort out the hardware I can reduce the aperture until an exposure of 1ms works for daytime as I did with the old QHY5.  Longer exposures for night-time mean the next update to oacapture.  I would like to use oacapture as it's in line with my desired policy of changing over to Linux wherever possible.

[Gina]

Sorting out the hardware.

In order to diagnose where the fault is I have been rebuilding the circuitry in stages. 

1. Soldered a socket for the Nano and a ULN2003A onto a new piece of stripboard and plugged a Nano in and tested - working - sketch responds to serial display input and reports correctly.
2. Added a pull-up resistor for the 1-wire - working.
3. Connected a DS18B20 - still working but display of the DS18B20 readout gave "Error".  This device was working fine before as the dome temperature sensor.
4. Connected micro servo motor as before to D9 for data and to Gnd and 5v.  Nano NOT working - a "USB disconnected" sound every few seconds and no response from the serial display.

With this very basic circuit I know the connections are correct - checked several times.  With two previously working devices now either not working or causing problems I surmise that the problem is probably the Nano.  So my next course of action will be to try another Nano (if I have one).  Maybe without the servo and just the 1-wire DS18B20.  OR I could test the DS18B20 on my 1-wire test and read ID Uno setup.

[Gina]

I tried the Nano that I had soldered in - on its own just connected to USB and it worked as expected, so I cleaned off residual solder and put it in the socket on my new circiut board.  IT WORKS - the DS18B20 is indicating ambient temperature (not in the dome at present) and the servo motor turs under Serial Display command line control   So there was a wiring fault of some sort on the old circuit board.

Now I can proceed to the next step of adding the IRLZ44N for dew heater control.

[Gina]

Updated layout.

IRLZ44N

[DrRobin]

Glad it is back working Gina, a few dark days [and nights] there.  After having a look round I have found a couple of open source projects for Raspberry Pi and since I have two at work doing nothing I might give it a try.  Will let you know if I get anything working.

My own ASC is now working a lot more reliably after running a 5V supply out to it.  I was using an active USB cable, but found it only supplies 200mA and a DFK31 can draw up to 500mA, so the Active extension is now running just as an extension and the camera is powered by the 5V supply.

Robin

[Gina]

Thanks Robin

Works with IRLZ44N connected

Still to do :-

1. Connect dew heater and apply power - 5v initially until I get automatic control set up.
2. Connect stepper motor and 12v supply.