HC-SR501 PIR Sensor Pyroelectric Infrared Module

Here is a short description of the HC-SR501 PIR Motion Sensor Module:

• What it is: A popular pyroelectric infrared (PIR) sensor module designed to detect human or animal movement by sensing changes in infrared heat signatures within its range.

• Key Specs:

  • Operating Voltage: 4.5V to 20V DC (outputs a standard 3.3V TTL high signal on motion detection).

  • Sensing Range: Adjustable up to 3–7 meters with a ~120∘ cone angle.

• Key Features:

  • Dual Triggers: Configurable via jumper for Repeatable Trigger (holds signal high as long as motion continues) or Non-Repeatable Trigger (pulses high then rests).

  • Onboard Potentiometers: Two mini trimpots to adjust both detection sensitivity (range) and delay time (holds signal high from ~0.3s to 5 minutes).

• Common Uses: Automatic lighting, motion-activated security alarms, occupancy sensing, and intruder detection in Arduino, Raspberry Pi, and home automation projects.