IR (Infrared) And PIR Motion Sensor With Arduino And With Raspberry PI

Types Of Infrared Sensors

Up to this point, what we read was about the basics of all IR sensors, in this part of this blog we will be discussing the interfacing of IR sensors with Arduino and with Raspberry Pi;  as you can see in the following image, the module has three output pins GND, VCC and signal. Out of which GND and VCC are explicitly used to power the module and we get output at the signal pin.  

So, to get the output from the sensor, you have to power the module through an Arduino or Raspberry Pi board and get the output on its output pin. You may be thinking this and yes, it is somewhat correct but there is a catch, what would you do if the sensor would not output accurately?? 

How Can We Tell That The IR Sensor Is Working or Not?

There could many reasons for not getting the correct output from the sensor and a few of them I have listed below.   

Program Issue

Yes! I know that you do not make such mistakes, but if the module is not working, then checking such small things can also help. So please try to check if you have connected the signal pin to the correct pin. 

Output Gain of 555 Timer IC is Not Adjusted Properly

This is the most commonly encountered issue; Such issues are aggravated by improper adjustment of the gain of the 555 timer IC and this problem can be resolved by adjusting the potentiometer mounted on the module to its correct position. 

Sort-Circuit In PIR Sensor

I don't think I need to explain this, you are smart enough to understand the reason for such issues. Any part of the module is overheating it means that the module is damaged and cannot be used further.

IR Sensor is Still Not Working

  - If an onboard part is not heating, take out your phone and turn on the camera on this module, if you see a red light from the sensor, you can tell that the module is fully functioning and all connections need to be rechecked. 

Arduino Code For Infrared Sensor

int SignalPin = 2;   // Connect the signal pin of IR module to the D2 pin of Arduino 
void setup() {
  pinMode(SignalPin, INPUT); // Initialize D2 as an INput pin
  Serial.begin(9600); 
}
int Object = HIGH;
void loop() {
  Object = digitalRead(obstaclePin);
  if (Object == LOW)
  {
    Serial.println("Object Not Found"); // If there is nothing in its path
    delay(200);
  }
  else
  {
    Serial.println("Obstacle Found"); //If there is obstacle 
  }
  delay(100);
}

IR Sensor Interfacing With The Raspberry Pi

IR Sensor Python Code For Raspberry Pi

import RPi.GPIO as GPIO # Import Raspberry Pi GPIO library 

def button_callback(Detection): 

print("Object Is detected") 

GPIO.setwarnings(False) # Ignore warning for now 

GPIO.setmode(GPIO.BOARD) # Use physical pin numbering 

GPIO.setup(34, GPIO.IN, pull_up_down=GPIO.PUD_DOWN) # Set pin 10 to be an input pin and set initial value to be pulled low (off) 

GPIO.add_event_detect(10,GPIO.RISING,Detection=Object_detected) # Setup event on pin 10 rising edge 

GPIO.cleanup()  

PIR Sensor Motion Introduction

Unlike an active infrared sensor, passive IR sensors do not require a separate transmitter and a receiver. Such IR sensors capture the ambient heat and detect the object based on a deflection in the reading. 

These sensors mainly used in home surveillance applications.

Senstivity And Delay Adjusment In PIR Motion Sensor

Apart from all these basics, if you check the module, you will see two potentiometers on the PIR sensor.

A potentiometer designated as sensitivity used to adjust the sensing the range. And a potentiometer designated as Output-timing used to adjust the delay.

Troubleshoot if the PIR module still doesn't work

There can be many reason in which the module may stop working and a few of them I have listed below.

PIR Motion sensor Arduino code

int led = 13;                // the pin that the LED is atteched to
int sensor = 9;              // the pin that the sensor is atteched to
int state = LOW;             // by default, no motion detected
int val = 0;                 // variable to store the sensor status (value)

void setup() {
  pinMode(led, OUTPUT);      // initalize LED as an output
  pinMode(sensor, INPUT);    // initialize sensor as an input
  Serial.begin(9600);        // initialize serial
}

void loop(){
  val = digitalRead(sensor);   // read sensor value
  if (val == HIGH) {           // check if the sensor is HIGH
    digitalWrite(led, HIGH);   // turn LED ON
    delay(100);                // delay 100 milliseconds 
    
    if (state == LOW) {
      Serial.println("Motion detected!"); 
      state = HIGH;       // update variable state to HIGH
    }
  }

import RPi.GPIO as GPIO  

From time import sleep 

GPIO.setwarnings(False)  

GPIO.setmode(GPIO.BOARD)  

GPIO.setup(14, GPIO.IN) #Read output from PIR motion sensor  

while True:  

input=GPIO.input(11)  

if input == 0: #When output from motion sensor is LOW 
   print ("No object detected",input) 
   sleep(0.1) 
elif input == 1: #When output from motion sensor is HIGH 
   print ("Object detected",input) 
   sleep(0.1)

Conclusion - 

In this section, I have tried to explain each about IR sensor and PIR sensor. I hope this blog has dispelled your doubts about IR sensors and PIR sensors.
If the there is any doubt please let me know in the comment section and I will try to solve my query there for sure.