A small distance from my house is a streetlight. The streetlight has been there as long as my house, about 8 years. In the last 8 years, the streetlight has behaved as proper streetlights do, coming on at dusk and going off at dawn.
All this changed about a month ago. The street- light started coming on at dawn, burning all day, then turning off at dusk and remaining off all night.
This event has shaken my faith in the embedded programming world. Is it possible that somewhere, a programmer wrote code for my streetlight that maintains a "nighttime" variable and then compliments its state on the dawn/dusk edge that the photo- detector sees? And never actually checks the reality of "day" or "night"? I can think of no other possible failure mode.
I'm considering an experiment consisting of shining a bright spotlight on the streetlight at night to see if that will trick it into proper operation.
Any thoughts on this bizarre behavior?