"Electronics Projects" for beginners part one

"Electronics Projects" for beginners part one

Dear mates, we're here to share with you our simple but useful project and step-by-step descriptive video to show you, how you can auto-turn on the room Light when someone come inside the room. It’s only work when someone moves in the room and after a few second lights will turn off automatically. To detect the motion I have used PIR Motion Sensor and program the Arduino board to read the sensor signal and turn on the light for a few seconds.

List of components to make this prototype.

  1. Arduino UNO
  2. PIR Motion Sensor
  3. LED
  4. Jumper Wire

The Code:

//the time we give the sensor to calibrate (10-60 secs according to the datasheet)
int calibrationTime = 30;       
//the time when the sensor outputs a low impulse
long unsigned int lowIn;        
//the amount of milliseconds the sensor has to be low
//before we assume all motion has stopped
long unsigned int pause = 5000; 
boolean lockLow = true;
boolean takeLowTime;  
int pirPin = 3;    //the digital pin connected to the PIR sensor's output
int ledPin = 13;
void setup(){
  pinMode(pirPin, INPUT);
  pinMode(ledPin, OUTPUT);
  digitalWrite(pirPin, LOW);
  //give the sensor some time to calibrate
  Serial.print("calibrating sensor ");
    for(int i = 0; i < calibrationTime; i++){
    Serial.println(" done");
    Serial.println("SENSOR ACTIVE");
void loop(){
     if(digitalRead(pirPin) == HIGH){
       digitalWrite(ledPin, HIGH);   //the led visualizes the sensors output pin state
         //makes sure we wait for a transition to LOW before any further output is made:
         lockLow = false;           
         Serial.print("motion detected at ");
         Serial.println(" sec");
         takeLowTime = true;
     if(digitalRead(pirPin) == LOW){      
       digitalWrite(ledPin, LOW);  //the led visualizes the sensors output pin state
        lowIn = millis();          //save the time of the transition from high to LOW
        takeLowTime = false;       //make sure this is only done at the start of a LOW phase
       //if the sensor is low for more than the given pause,
       //we assume that no more motion is going to happen
       if(!lockLow && millis() - lowIn > pause){ 
           //makes sure this block of code is only executed again after
           //a new motion sequence has been detected
           lockLow = true;                       
           Serial.print("motion ended at ");      //output
           Serial.print((millis() - pause)/1000);
           Serial.println(" sec");
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