Abstract: A daylight sensor system includes a power circuit that converts high voltage AC to low voltage DC. The system includes a microcontroller, a motion detector, and a photodiode (PD) integrated circuit (IC). The PD IC provides an output to the microcontroller that is indicative of a lux reading in the vicinity of the system. In response, the microcontroller activates or deactivates a latching relay, which is connected to a line voltage and a load. The motion detector whether the daylight sensor system will be in an active mode of operation or an inactive mode. The microcontroller is programmed so that if the motion detector fails to detect motion for a certain amount of time, the microcontroller will go off line until the motion detector senses motion again.