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| HW-416-B | Arduino Uno/Nano | | :--- | :--- | | VCC | 5V | | OUT | Digital Pin 2 (or any) | | GND | GND |
The internal BISS0001 (or equivalent) IC amplifies this signal.
When power is first applied to the HW-416-B, it requires anywhere from 30 to 60 seconds to learn the ambient infrared signature of the room. Any readings during this initialization window should be ignored. hw-416-b pir sensor datasheet
| Problem | Likely Cause | Solution | | :--- | :--- | :--- | | Sensor always HIGH | Power supply noise or shorted transistor | Use a regulated 5V supply; add 100µF capacitor across VCC/GND | | Sensor never triggers | Sensitivity too low or lens obstructed | Turn sensitivity pot clockwise; clean Fresnel lens | | Triggers randomly/too often | RF interference or heat source (AC vent, sunlight) | Reduce sensitivity; change mounting position | | No output after 30 min | Some modules enter power-save mode | Cycle power or configure for continuous trigger mode | | Output stays HIGH too long | Time delay set to maximum | Turn "TIME" pot fully counter-clockwise |
Turning this clockwise increases the detection distance (up to ~7 meters). Turning it counter-clockwise decreases the range, which is helpful for small rooms to prevent false triggers. | HW-416-B | Arduino Uno/Nano | | :---
5 seconds to 200 seconds (Adjustable via onboard potentiometer)
| Application Category | Use Cases | |---------------------|-----------| | | Burglar alarms, motion-triggered cameras, perimeter monitoring | | Smart Lighting | Automatic hallway/staircase lights, bathroom fans, garage lighting | | Home Automation | Occupancy detection, energy-saving systems, smart room control | | Industrial Automation | Machine safety zones, presence monitoring, automated doors | | STEM Education | Arduino/Raspberry Pi learning projects, robotics, IoT demonstrations | | Energy Management | Classroom/office lighting control, storage monitoring | | Problem | Likely Cause | Solution |
The HW‑416‑B is a passive infrared motion sensor that detects movement by sensing changes in infrared radiation—primarily the heat emitted by humans and animals. When motion is detected, the module provides a digital HIGH signal on its output pin; when no motion is present, the pin stays LOW. This simple digital output makes it extremely easy to interface with microcontrollers such as Arduino, ESP8266, ESP32, and Raspberry Pi.
When designing your next motion-sensing project, remember:
If your HW-416-B is outputting false positive triggers, consider the following variables:
The following sketch reads the PIR sensor once per second and prints the result to the Serial Monitor: