Light level sensor to control shutter relay?

I have a shutter control relay which I use with the Wiser 2 widget to open and close some curtains, I have been looking at ways to automate this process but cannot see an easy way of linking the open and close functions to the Sunrise and Sunset times as I think I need a variable offset from these times according to the time of the year, If I set an offset based on the winter sunset time this would result in the curtains closing much too early in the summer as here at 53 degrees north the time between sunset and "darkness" varies considerably throughout the year. I have a SENLL light level sensor which I use to control some lights so that they come on when it is dark and go off when it is light (this means that they also come on during the day if the light level drops because of cloud cover).

I have looked at scheduling the operation with PICED and the Wiser but although the widget control works I cannot get the relay to respond to any light ON OFF or light percentage values I input.

Has anyone any experience of using a light level sensor (not necessarily a SENLL) to control something like a shutter relay with a defined night time period so that the curtains don't react to transient drop in light level.?

Any comments or advice would be appreciated.

 

With the shutter relay, setting its group address to 0% closes the shutter, and setting it to 100% opens the shutter. The light level sensor works the opposite way however, so it sets its group address to 100% when to light level falls below the threshold and 0% when it goes above the threshold. Since you have a Wiser 2 you could just write some simple logic to trigger the shutter when the light level ga changes. You could also add in a delay so it wouldn't respond to short changes in light level. If logic is new to you, we can help you out there.

As for the sunset time, it always annoyed me that they used the actual sunset time rather than last/first light which would have been much more useful and easy to do. In fact they should have let you select the actual sun angle used to calculate the sunrise/sunset times. That's what I did in my own code anyway

 

Thanks Ashley for that useful information and the offer of help. I will have a look at the PICED manual to see what might be involved in programming some logic to do as you suggest and then come back to you.