The HW-416-B is a ready-to-use PIR motion detection module that combines a pyroelectric infrared sensor, an integrated signal conditioning circuit (built around the chip), and a dome-shaped Fresnel lens that focuses infrared radiation onto the sensor element. The module includes onboard adjustments for sensitivity and output delay, as well as a jumper for selecting trigger behavior.
All matter with a temperature above absolute zero emits thermal energy in the form of infrared radiation. Human bodies radiate infrared light at a wavelength of roughly 9 to 10 micrometers. hw-416-b pir sensor datasheet
1.0 Date: Based on common HW-416-B specifications as of 2026 Compliance: RoHS (lead-free) for most variants The HW-416-B is a ready-to-use PIR motion detection
Turning clockwise increases the detection distance. Human bodies radiate infrared light at a wavelength
The following sketch reads the state of the HW-416-B sensor. It turns on the built-in Arduino LED (Pin 13) and prints alerts to the Serial Monitor when motion is detected.
At its core, the module utilizes a pyroelectric sensor covered by a specially designed Fresnel lens. The lens focuses infrared radiation onto the sensing element. When a warm body moves across the sensor's field of view, the internal electronics process the differential signal and trigger a digital high output. Key Benefits
void setup() Serial.begin(9600); pinMode(motionPin, INPUT); pinMode(ledPin, OUTPUT); Serial.println("HW-416-B warming up..."); delay(60000); // Critical: Allow 60s stabilization