This is a Pachuino that changes LED output in response to the light sensor of a remote Pachuino. There is also a light sensor next to the LED which is one of the sensor values in the EEML feed (that the remote Pachuino, which is pretty much identical, uses to set its LED level). Since the light level number is inversely proportional to the light level (i.e. it goes up when the light level goes down) but it is setting the LED level proportionally (i.e. up = up), we should eventually see a feedback loop where the LEDs (remote and local) start flashing at a particular rate. There is also a thermistor touching the LED: I don't know whether this will make a difference but it might be that there is a little bit of a temperature rise when the LED has tended to be on for a long time. (Search also for the other Global Feedback loop feed).

Website: http://www.pachube.com/feeds/76