Joachim/Paul - I noticed that you were having some problems getting the SSM to work. When I had to troubleshoot my build, I changed the resistor for the photodiode FROM 220 ohms TO 220K ohms so that I could use an LED flashlight to replace the sun as I was working indoors. I used the recommended VTP4085 photodiode, which yields about 1mA out for the 10K foot candle (FC) output of the sun;changing the resistor three orders of magnitude puts the sensitivity in the range of ten FC which allows the use of household lights as a stable, indoor sun.
I have other troubleshooting notes, but unfortunately they are not in my astronomy or electronics notebook; if I find the sheets of paper that they are written on, I'll post them. I am not a member of the other forum that you posted your problems on, but I know that you look in here.
