How to use elevation and azimuth etc to achieve a useful trigger

I have electric blinds which I try to keep closed until the sun stops blazing in. I though I had it sorted based on azimuth but as the seasons change its all going pear shaped.

Has anyone got a formula?? using I guess, latitude, longitude, direction facing and extent of balcony shade, see diagram.

This is not a trivial calculation. Even leaving out daylight savings.

I’d use a tool like this: https://www.suncalc.org/#/-33.7167,151.2833,3/2020.02.02/12:00/1/3 to get some values of az/alt from sunrise to an hour or so past midday for each month of the year. Tabulate them and see if you can break them down to simple rules or times per month.

A simpler method might be a lux sensor in the window.

@tom_l, thanks for your input. I’ve been logging elev and azim for some months and it does not jump out at me as to how to spot the way to get a rule from it. The problem with having a light sensor at close to floor level is ‘small children’, grandkids in our case !!

I do use a temp gradient sensor on a window on the opposite side of the apartment but that is much less accessible to small ones!. This works well. Maybe it is the way to go though. Unless a scientist with fluency in this problem pops up.!!

@ianadd

Did you find a simple solution for your blind based on elevation and azimuth ?

@papoo no I haven’t. As it is winter here in southern hemsphere my processing is now driven by wanting the heat of the sun and so the blinds go up on sunny mornings as soon as the sun is 4degrees above horizon. Next summer I will have another search for help/ideas.

shame, i will keep looking