More info at https://dronebotworkshop.com Code & Article at https://dbot.ws/hcsr501 The HC-SR501 is a PIR (Passive Infrared) motion sensor that is very inexpensive and extremely versatile. This device can be used all on its own or with a microcontroller or microcomputer for additional functionality. The HC-SR501 has a built-in voltage regulator so it can run on […]