It all started with a simple Pummer:
As you can see in this video (a Pummer by Mark):
This Pummer is unusually fast pumming – but you get the idea.
A Pummer consists of a solar cell and a circuit to strobe a LED after dark. Nothing more, nothing less. Due to the solar cell it runs forever and is completely care free.
I really dig the idea of gathering the light of the day and play it by night. But it was somehow quite indirect for my taste. So I came up with the idea of really recording the light and playing it back at night. The first idea was to use an AVR ATTINY micro controller to constantly measure the light and store it in its internal memory.
But playing back the pattern all night was a waste of energy. And when it is night? And is there somebody to watch it? If not it would be a waste of (precious) energy. So I added a temperature sensor to measure the touch of a hand. The light pattern should be played back if somebody takes it in his hand.