Tag: LHI778
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Optical Evaluation of a PIR
Overview of the HC-SR501 PIR Motion Sensor The HC-SR501 passive infrared (PIR) motion sensor is popular with Arduino enthusiasts due to its low cost, on-board controls, and customizability. At the heart of this sensor are two pyroelectric elements inside a TO-5 can. The use of pyroelectric elements is fundamentally why this device is sensitive to…