If you want to build a device that is used to detect and sense motion and almost always used to detect whether a human has moved in or out of the sensor's range. Then this sensor is needed for you. you can buy this sensor from vyomtics.com, at a reasonable price
The PIR motion sensor detector module HC-SR501 allows you to sense motion. It is almost always used to detect the motion of a human body within the sensor’s range. It is often referred to using "PIR," "Pyroelectric," “Passive Infrared," and “IR Motion” sensors.
The module has an onboard pyroelectric sensor, conditioning circuitry, and a dome-shaped Fresnel lens. It has a delay time adjustment. Potentiometer and sensitivity adjustment potentiometer. Compatible with ARDUINO, RASPBERRY PI, AVR, PIC, 8051, etc.
To know more about how to interface PIR sensor with a Raspberry Pi, click here: https://www.hackster.io/rjrobotics007/how-to-interface-hc-sr501-pir-sensor-with-raspberry-pi-893f5c
Note: The product is available in two colors, blue and green; therefore, packing may result in you getting any one of them.
Features:
1. Infrared Sensor with Control Circuit Board
2. The sensitivity and holding time are adjustable.
3. Blockade time: 2.5s (Default)
4. Sensitive Setting: Turn to the right, Distance Increases (About 7M); Turn to the left, distance reduces (About 3M)
5. Time Setting: Turn to the right, time increases (about 200S); turn to the left, time reduces (about 5S).
Package Includes:
1 x PIR Motion Sensor Detector Module HC SR501
