Infrared Motion Sensor HC-SR501 is used to detect motion in a controlled area of objects that emit infrared radiation (heat). The principle of operation of the sensor is based on a Pyro.
Pyroelectricity - this property is certain to generate an electric field when irradiated material infrared (heat) radiation. Over sensor installed Fresnel lens, which is used to increase the radius of the review and strengthening of the incoming infrared signal.
In order to use motion sensor HC-SR501 need to connect the power, connect to the controller, place the sensor in the measuring medium. Then you need to write to the controller a special program that allows you to work with the sensor. Then you can begin work. Not raspolagaqnt sensor in places where the temperature is changing rapidly! This leads to the fact that the sensor can not detect the appearance of an object in the monitored zone, and will be a lot of false positives.
The module has two modes of operation:
- 1. Mode H. When a sensor is triggered repeatedly at its output (in OUT) is a logic high.
- 2. Mode L. The output mode each time the sensor appears single pulse.
In motion sensor HC-SR501 has multiple controls and settings:
- terminals to switch modes. Designation terminals: L, MD, H.
- Two Trimmer Resistors:
- Sx is regulated sensitivity (from 3 to 7 m);
- Tx to set the time (from 5 to 300 seconds), during which the motion detection to OUT will be a logical unit.
Infrared Motion Sensor HC-SR501 has one interface to the microcontroller. This 3-pin male interface.
Contacts infrared motion sensor HC-SR501 :
- OUT (output signal) - contact for communication between the sensor and the microcontroller;
- VCC - power supply;
- GND - common contact.
Power motion sensor HC-SR501 is performed by the controller Arduino, or other control microprocessor device, or from an external power supply (power supply, battery).
voltage motion sensor HC-SR501 4,5 - 20 V.