Description
HC–SR501 Motion Sensor Module with an operating voltage range of 4.5V DC to 12V DC.
When used with a microcontroller board the module’s output (trigger) pin will put out 3.3V. You can attach that pin to one of microcontroller’s (Arduino, Raspberry Pi, etc.) input pin to know when someone has walked by. You can also attach the trigger pin to the sense input of our trigger relays to make an activation switch that requires no controller, only a 5V power source. Be sure to check out this video on The Maker’s Cave YouTube channel for some ideas. https://www.youtube.com/watch?v=-HE9Bkcsk2o&t=1s
The module has two adjustable potentiometers. One will adjust the sensitivity of the sensor from approximately 9 feet to 21 feet. However, we have found when the sensitivity is turned up almost any movement greater than a 18″ from the sensor will trigger it. The other potentiometer adjusts the delay of re-triggering from 3 seconds to 5 minutes. This sets how long after the last trigger will the sensor be allowed to trigger again.
The module also has a jumper pin that sets the how the trigger repeat will be applied. When set to “H” the sensor will trigger again regardless of the trigger delays set by the potentiometer. When set to “L” the module will not trigger again until after the delays are done. The most common setting is “L”.
The boards power and trigger features are accessed with header pins that accept standard dupont connectors. You can also order this module with 18″ of cable with one end with the dupont connectors and the other end terminating with bare leads ready for attachment to your project or microcontroller.
