SR501 PIR Sensor

SR501 PIR Sensor

The SR501 PIR Sensor is a passive infrared motion detector designed for reliable motion sensing in various applications. It utilizes a pyroelectric sensor and Fresnel lens to detect infrared radiation changes caused by moving objects. The module features adjustable sensitivity and delay time, allowing customization for different environments. Its compact design and low power consumption make it suitable for battery-powered devices and embedded systems.

Features

• Passive infrared motion detection.
• Adjustable sensitivity and delay time.
• Dual trigger modes: repeatable and non-repeatable.
• Wide operating voltage range.
• Low quiescent current for energy efficiency.
• Compact size with mounting holes for easy installation.

Specifications

The digital output allows connection of the sensor to any board equipped with a microcontroller, e.g. Arduino, STM32 Discovery or minicomputer Raspberry Pi.

Thanks to a potentiometer, the user can adjust:

• T1– duration of the high state upon detection of the object
• T2– sensor sensitivity (distance, which detects the movement of an object)

With the jumper, which has to be self-soldered, mode of operation is selected from two available outputs:

• retriggering (jumper in H position) – the output reaches a high status, after the detection of the object and it is held for the entire time of detection of continued motion, the sensor, by default, is in this mode (no jumper).

• non-retriggering (jumper in position L) – the output reaches a high status only once, after detection of the object and then goes to a low status, regardless of whether the movement continues

Module Connections

There is a 3-pin header on the assembly.  The markings are hidden by the plastic dome, so refer to the picture for the pin-out. The dome can also be easily removed to see the markings.

PINOUT

• VCC =   Connect to 4.5V to 20V
• OUTPUT =  Digital sensor output (active HIGH) – Normally connects to a digital input pin on a uC
• GND =  Connect to system ground.  This ground needs to be in common with the uC

Applications

• Automated lighting control.
• Security and intrusion detection systems.
• Energy-saving devices.
• Home automation projects.
• Robotics and motion tracking.

Package Contents

• 1x SR501 PIR Sensor.

Documents

• SR501 Sensor datasheet.