Astronomical timer for a USB relay?

[michaelmorris]

I'm currently running two Watec902H cameras with fast auto-iris lenses for detecting meteors. Both cameras are on timers so that when the power is off the auto-iris lens will automatically shut, protecting the camera chip.

At the moment I'm using off the shelf cheap plug-in electronic timers. The problem is that every week I need to remember to alter the on and off times to fit in with changes in local sunset and sunrise times.

Specialist astronomical clock timing relays are very pricey. However, there are lots of USB controlled relays that would be suitable for under £20. Does anyone know of any astronomical timer software available for these devices?

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[michaelmorris]

Anyone?

[Alien 13]

I dont know of any but it could be made to work off a mobile phone app but would probably have to be a diy job but even a very cheap host phone would have all the time info plus light/dark and gps info available.

The interface could be driven off the headphone skt,usb or even bluetooth, i use an app called dslr remote that has all the timer functions but not the length of day info.

Alan

[james_screech]

It shouldn't to too difficult to write a simple application to do that, I've seen libraries (c++ & c#) that can be used to calculate sunrise / sunset times. Presumably the USB relay cards also come with an interface library. You just need to find a local software engineer who is interested in astronomy, you could try your local astronomy club. Sorry but I'm a bit too far away.

James

[JamesF]

I wonder if it might be easier (and perhaps more reliable?) to have relays triggered by a light sensor of some sort?  Could you put this sort of thing in the power line for the camera, for instance?

http://www.rapidonline.com/Design-Technology/Velleman-Light-Sensitive-Switch-Kit-70-4150/

James

[TCWORLD]

It may be possible to do something using an arduino/Ethernet shield. Have it connected to the internet via Ethernet and automatically fetch sunrise/sunset times. That way you wouldn't need a computer running 24-7. I've seen one example that uses an Ethernet shield to fetch weather data (including sr/ss times).