The HiLetgo 3pcs HC-SR501 PIR infrared sensor module offers a reliable and cost‑effective solution for motion detection in Arduino and Raspberry Pi projects. Each module is built with a compact design that integrates a passive infrared element, a Fresnel lens, and a stable circuit board to detect human body infrared radiation. The sensor operates at a voltage range of 5V to 20V and provides a digital output signal that can be directly read by microcontrollers. Its detection range extends approximately 7 meters with a 120‑degree cone angle, making it suitable for indoor security systems, automatic lighting, and interactive installations. The module features adjustable sensitivity and time delay through onboard potentiometers, allowing users to fine‑tune the trigger distance and hold‑time from a few seconds to several minutes. The repeatable trigger mode ensures continuous output when motion is repeatedly detected, while the non‑repeatable mode resets after each detection. The PCB is constructed with high‑quality materials and undergoes consistent quality control, providing stable performance even in varying ambient temperatures. The three‑pack format offers excellent value, enabling multiple sensors to be deployed across different zones without breaking the budget. Hardware durability is reinforced by a solder‑masked board and clearly labeled pin headers (VCC, GND, OUT) that simplify wiring. The module works with common microcontroller platforms such as Arduino Uno, Mega, Nano, and Raspberry Pi GPIO, as well as other 5V/3.3V logic systems. No additional library is required, and basic digital reading code can be implemented instantly. The low power consumption, typically around 50µA in standby, makes it ideal for battery‑powered applications. At an extremely affordable price point, this sensor pack delivers practical functionality for hobbyists and educators seeking to add motion awareness to their projects. The tangible feel of the module’s shell is smooth, and the lens is securely attached. While the sensor works best in indoor environments without direct sunlight or strong heat sources, its performance remains consistent under typical household conditions. The design emphasizes simplicity and accessibility, allowing even beginners to quickly integrate human motion detection into their builds. For more advanced users, the adjustable settings enable customization for up to three separate sensor units with different delays and sensitivities, reducing the need for additional programming work.

The HiLetgo 3pcs HC-SR501 PIR sensor pack combines solid hardware construction, user‑friendly configuration, and remarkable value. The module delivers dependable motion detection for a wide range of microcontroller‑based projects, from security alarms to automated lighting. Its straightforward operation and affordable pricing make it a practical choice for those exploring infrared sensing technology without committing to higher‑cost alternatives.