Logging when the sun goes down
I realised that it was a bit pointless checking how much current the panel was producing after dark, and since I have a RaspberryPi doing the work (via an Arduino) which is connected to the battery, it is likely using more energy processing all those reads/writes needlessly.
I had tried using a simple cronjob to control when the solar sensing service should start and stop, but wasn't happy that in these short days, it was going on far too long.
So, @davea and I did a little hacking on the script with PyEphem and python-crontab, and the result is quite pleasing; as of this morning the script figures out when it should stop and next start, on startup, writes the times to the crontab and then goes about its business. At end of civil twilight (sunset), the service is stopped, and will be started again in the morning at start of civil twilight (sunrise).
Check out the graph at the top, to see the result this morning- sensing began just before the current started to rise. I'm not sure how much energy it will save, but I figured that in such a situation every little bit will make a difference.
