HC-SR501 PIR Motion Detection Sensor

The HC-SR501 PIR Motion Detection Sensor is a low-cost passive infrared sensor that detects the presence of humans or animals by sensing the infrared radiation they emit. It is a core component in home and workspace security systems, motion-activated lighting and general presence-detection projects.

The module is fitted with a Fresnel lens and onboard signal-conditioning circuitry to improve its field of view, covering up to 120 degrees and a 7 metre range. Two onboard potentiometers let you independently adjust sensitivity and holding time, while a jumper selects whether the output stays high or resets after each detection.

• Supply voltage – 5V
• Output – 3.3V TTL logic
• Detection range – Up to 120° coverage and 7m range
• Sensor type – Infrared sensor with onboard control circuitry and Fresnel lens
• Adjustability – Sensitivity and holding time both adjustable via potentiometers
• Power consumption – Low power draw of 65mA
• Operating temperature – -20°C to 80°C
• Trigger modes – Selectable repeatable or non-repeatable output

To use the sensor, power it with 5V and GND from your controller and connect the output pin to any GPIO. Adjust the sensitivity and time delay to match your environment, then select the output mode that suits your application. The HC-SR501 PIR Motion Detection Sensor is a dependable choice for motion-activated lights, alarm systems and smart home projects built around Arduino, Raspberry Pi or similar controllers.