PIR Sensor Arduino Interfacing

PIR Sensor Arduino Interfacing

1. PIR Sensor Pins

• PIR sensor has three pins voltage, output and ground respectively.
• All of the pins are provided in the table shown in the figure given below.

2. PIR Sensor Pins Description

• Each pin has different task to perform while the sensor is in working condition.
• PIR sensor pin descriptions are listed in the table shown in the figure below.

3. PIR Working Principle

• PIR sensor has two different slot which are sensitive to infrared light/energy.
• When the sensor is in normal condition, both of the slots measure the same amount of infrared energy radiated by walls etc.
• When a warm body e.g animals and human beings crosses its coverage area, they first cross PIR sensors's first slot, which produces positive differential change between two slots.
• When an animal or human being leave from the sensing area, a corresponding negative differential change is produced.
• By detecting these types of changes PIR sensor can detect the motion of different objects which radiates infrared energy.
• I have tried to elaborate the PIR working principle through some visuals shown in the figure given below.

• I have also provided the visuals about how PIR sensor generates an output signal after sensing different objects/
• PIR sensor object sensing is given in the figure shown below.

4. PIR Sensor Schematic Diagram

• To understand the internal structure of any electronic device, we must have a look at its schematic diagram.
• PIR sensor schematic diagram is shown in the figure given below.

5. Apparatus Required

• PIR (Passive Infra Red) Sensor
• Arduino (Microcontroller)
• Jumper wires

6. PIR Interfacing with Arduino Wiring Diagram

• I have already shared a brief article on Interfacing PIR sensor with Arduino.
• Now, this is a detailed article about the similar topic.
• I have provided wiring diagram for PIR interfacing with Arduino.
• You can make the similar wiring diagram and can test and verify your results as well.
• PIR Sensor Arduino Interfacing wiring diagram is shown in the figure given below.

7. PIR Sensor Arduino Interfacing Source Code and Description

• If you have never use Arduino software for programming then you should first go through How to Write Arduino Code.
• I have provided the complete source code for PIR interfacing with Arduino.
• You just need to copy and paste the entire code and upload it to your Arduino board and observe the results.
• You can also made the same simulation on Proteus as well and can verify the results.
• In case of Proteus simulation you must need to know about How to get Hex File from Arduino.

int LED = 13;                
int inputPin = 2;               
int PIR_STATE = LOW;             
int VALUE = 0;                   
 
void setup() {
  pinMode(LED, OUTPUT);      
 
  Serial.begin(9600);
}
 
void loop(){
  VALUE = digitalRead(inputPin); 
  if (VALUE == HIGH) {           
    digitalWrite(LED, HIGH); 
    if (PIR_STATE == LOW) {
      // we have just turned on
      Serial.println("Motion has been detected!");
      PIR_STATE = HIGH;
    }
  } else {
    digitalWrite(LED, LOW); 
    if (PIR_STATE == HIGH){
      // we have just turned of
      Serial.println("Motion has been stopped!");
      PIR_STATE = LOW;
    }
  }
}

• I have initialized the LED pin, PIR state pin and the pin and a variable for reading sensor's data.
• Then I have checked whether the detected value from the sensor is above or below the certain level.
• Then I have decide to be print the certain values on Serial Monitor.
• If it is above the certain level a message "Motion has been detected" will be displayed on the serial monitor through Serial Communication.
• If the detected value is below the certain level then the message "Motion has been stopped" will be displayed on the serial monitor in Arduino software.
• So, that was the brief description of the source code designed for PIR interfacing with Arduino.
• You can download the complete wiring diagram along with the complete Arduino source code here by clicking on the button below.

8. PIR Sensor Interfacing with Arduino Actual Circuit Diagram

• I have also provided the actual circuit diagram for PIR interfacing with Arduino.
• Actual circuit diagram is shown in the figure given below.

9. PIR Sensor Ratings

• To know the power, current and voltage requirements of an electronic device can be known through its ratings.
• PIR sensor ratings are listed in the table given in the figure shown below.

10. PIR Sensor Features

• A device can be popular on the basis of its amazing and unique features, which make it different from other devices.
• PIR sensor some of the main features are listed in the table given in the figure shown below.

11. PIR Sensor Applications

• PIR sensor has several different real applications.
• Some of common applications associated with PIR sensor are provided in the table shown in the figure given below.

• I have provided a circuit designed for security alarm system, which is its most common application.
• The complete circuit design for security alarm system is given in the figure shown below.

• PIR sensor's another application is making a timer circuit using PIR.
• I have provided timer circuit using PIR sensor, shown in the figure given below.

• Another most common application of PIR sensor is the motion detection.
• Motion detection circuit diagram using PIR sensor is shown in the figure given below.

12. PIR Sensor Advantages

• There are a lot of advantages associated with Passive Infrared Sensor, few of them are given below.

13. PIR Sensor Disadvantages

• Infrared sensors also have some disadvantages but they are in a very small as compared to its disadvantage.
• Infrared sensor disadvantage are listed in the table given in the figure shown below.