Unlike the HC-SR501, many HW-416B modules do not have 5V tolerant logic outputs. The output pin is 3.3V. Do not connect it directly to a 5V-only Arduino input without a level shifter, or you may damage the sensor over time.
| Adjustment | Effect | |------------|--------| | | Clockwise increases detection distance (up to ~7 m); counter‑clockwise reduces it (down to ~2 m) | | Lowest setting | Approximately 3 m detection distance | hw416b pir sensor datasheet better
Always account for the in your system design. If you need immediate detection, consider keeping the sensor powered continuously or using a more sophisticated power management scheme. Unlike the HC-SR501, many HW-416B modules do not
In this mode, the output remains HIGH as long as motion is continuously detected. Each time motion is detected, the delay timer resets. The output will only go LOW after the delay period has elapsed without any motion detection. | Adjustment | Effect | |------------|--------| | |
Selectable between repeatable and non-repeatable triggers.
#define PIR_PIN GPIO_NUM_4
The is one of the most reliable and widely implemented motion-sensing modules available for electronics enthusiasts, hardware engineers, and DIYers alike. Often sold interchangeably under the iconic HC-SR501 designation , understanding its technical specifications is critical to unlocking its full potential.