摘要 |
A wireless light sensor, being part of a lighting system, has a sensor element generating a light measuring signal, a microcontroller coupled to the sensor element, and a radio communication device coupled to the microcontroller. The microcontroller has an active mode and a sleeping mode. The light sensor further has a wake-up circuit which determines a rate of change of the light measuring signal, when the microcontroller is in the sleeping mode. The wake-up circuit brings the microcontroller from the sleeping mode into the active mode, when the rate of change of the light measuring signal exceeds a predetermined threshold. |