HC-SR50R MINI PIR SENSOR

The HC-SR505 is a small, low-power Passive Infrared (PIR) sensor module designed for automatic control, sensing human body movement, and security applications. It is a miniaturized version of the larger, standard HC-SR501 PIR sensor, offering a smaller footprint and simpler operation.

1. Passive Infrared Sensing: The sensor operates by detecting changes in infrared radiation (heat) within its field of view. When a warm body (like a person) moves across the detection zone, the thermal signature changes rapidly, triggering the sensor.

2. Output Logic: Unlike larger PIR modules, the HC-SR505 usually offers a single, straightforward digital output:

   • HIGH (3.3V): Motion detected.

   • LOW (0V): No motion detected.

3. Fixed Configuration: The HC-SR505 is known for its simplicity as it lacks the fine-tuning adjustments (sensitivity and delay time potentiometers) found on its larger counterparts. The default settings typically include:

   • Operating Voltage: 4.5V to 20V DC.

   • Sensing Angle: Approximately 100 degrees.

   • Detection Distance: About 3 meters.

   • Delay Time: A very short fixed delay (often 8 seconds), after which the output returns LOW if no further movement is sensed.

Due to its small size and low current consumption, the HC-SR505 is ideal for battery-powered projects, smart home devices, DIY security systems, and embedded electronics where space is a premium and simple human presence detection is required.