- PIR – Passive InfraRed Sensor
- PIR consists of a Pyroelectric sensor which generates energy when exposed to heat.
- The module covered with Fresnel Lense Cover.
- BISS0001 micro Power PIR Motion Detector IC.
Infrared Application
- Passive Infrared Detector for Anti Theft security alarm system.
- Passive Infrared Detector based Light On/OFF.
- Automatic Light ON/OFF.
- Many other motion Detection Application.
Different PIR Modules
The HC-SR501 PIR Sensor Module
- Working voltage : 5v to 20V DC
- Range : 3 to 7 meters
- Induction Lens size: 23mm.
- PCB Size: 32mm x24mm.
- Pins Details
- Ground pin
- VCC pin
- The output pin detects an object when it is at a high logic level.
- Two potentiometers.
- One for adjusting the sensitivity of the sensor
- Adjust the time for the output signal to stay high when an object is detected from 0.3 seconds up to 5 minutes.
- Jumper Settings (Selecting the trigger modes)
- non-repeatable trigger – when the sensor output is high and the delay time is over, the output will automatically change from high to low level.
- Repeatable trigger – will keep the output high all the time until the detected object is present in sensor’s range
Arduino Example code :
Circuit
Code
/* Arduino PIR Motion Sensor Tutorial */ /* www.ArunEworld.com */ int pirSensor = 8; int relayInput = 7; void setup() { pinMode(pirSensor, INPUT); pinMode(relayInput, OUTPUT); } void loop() { int sensorValue = digitalRead(pirSensor); if (sensorValue == HIGH) { digitalWrite(relayInput, LOW); // The Relay Input works Inversely } }
Code Explanation
This Arduino code is for a PIR (Passive Infrared) motion sensor setup, where a relay is controlled based on motion detection. Here’s an explanation of each part:
Section | Explanation |
---|---|
Comments | The code includes comments providing information about the purpose of the code and its source. |
Variable Declaration | – pirSensor = 8; : Declares a variable pirSensor and assigns pin 8 to it for reading the PIR sensor’s output. – relayInput = 7; : Declares a variable relayInput and assigns pin 7 to it for controlling the relay. |
Setup Function | Initializes the pins: – Sets pirSensor pin as INPUT to receive data from the PIR sensor. – Sets relayInput pin as OUTPUT to control the relay. |
Loop Function | – Reads the digital state from the pirSensor pin to check for motion detection. – If motion is detected (sensor value is HIGH), it turns on the relay by setting the relayInput pin LOW. |