A candle that ignites itself when you turn off the lights.
Inside the jar, a photoresistor detects changes in the ambient light. When the room goes dark, a microcontroller sends current through a nichrome wire filament to heat it up. A servo motor opens up a stream of butane, which is ignited by the filament, providing the flame. Once the flame is lit, the filament turns back off, and the butane sustains the flame. The flame goes out when the photoresistor detects that the lights have come back on in the room.
Collaborators: Kiran Matharu