HC-SR501 PIR Motion Sensor Module

The HC-SR501 PIR Motion Sensor Module is a highly reliable, low-cost passive infrared (PIR) detector engineered to detect human or animal movement by tracking changes in ambient infrared radiation signatures. Driven by a dedicated BISS0001 processing chip and paired with a segmented hemispherical Fresnel lens, the sensor focuses infrared rays directly onto an underlying dual-element pyroelectric sensor crystal. This hardware arrangement provides exceptional sensing stability, low power draw, and an expansive detection cone up to 120 degrees wide.

Operating seamlessly on a broad input voltage threshold ranging from 4.5V to 20V DC, the board outputs a clean, high/low 3.3V logic signal that interfaces directly with microcontrollers like Arduino, Raspberry Pi, ESP32, and PIC chips without requiring complex voltage dividers. The module includes two onboard trimmer potentiometers, allowing users to manually calibrate the detection distance from 3 to 7 meters and modify the output high-time delay anywhere from 5 seconds up to 5 minutes. This adaptability makes it the quintessential choice for home automation hubs, burglar alarms, automatic walkway lighting, interactive art displays, and smart robotics.

• Adjustable Dual Customization: Features two precision orange trimmer potentiometers to easily customize sensitivity (distance range) and time delay without reloading firmware.
• Dual Operational Trigger Modes: Built with an on-board jumper pad select layout to alternate between Repeatable Triggering (keeps output high as long as continuous motion is detected) and Single Triggering (pulses low after time-out even during movement).
• Wide Voltage Compatibility: Runs on standard 5V or 12V rails while outputting a safe 3.3V logic high signal, preventing accidental port damage to low-voltage microcontrollers.
• Segmented Fresnel Lens Protection: The translucent snap-on white dome acts as a protective shield while focusing multi-angle infrared wavelengths onto the core pyroelectric crystal.
• Low Idle Current Draw: Consumes less than 65 microamps during static standby mode, making it excellent for long-running, battery-powered remote IoT sensor installations.

• Sensitivity Potentiometer (Sx): Turning this trimmer clockwise increases the detection distance (up to ~7 meters); turning counter-clockwise decreases the range (down to ~3 meters).
• Time-Delay Potentiometer (Tx): Turning this trimmer clockwise increases the duration the output pin stays HIGH after a trigger event; turning counter-clockwise shortens the delay down to ~5 seconds.