Motion sensor alarm system

What you will learn here about motion sensor alarm system

  • Motion sensor alarm system

The motion sensor alarm system turns ON buzzer ( as an alarm) on movement detection and turns buzzer OFF when movement is not detected. Here we will see how to implement the motion sensor alarm system with esp8266.
Hardware requirements:

  • PIR sensor
  • ESP8266
  • USB to power ESP8266
  • Buzzer
  • Resistor (Limit sound of buzzer)
  • Connecting wires

Motion sensor alarm system

Simple motion sensor alarmĀ  system using ESP8266 is shown below

Buzzer alarm motion sensor

Hardware connection

  • Connect VCC pin of PIR to 3.3v or Vin of ESP8266
  • Connect the output of PIR to GPIO14 i.e D5 of ESp8266
  • Connect GND of PIR to GND of ESP8266
  • Connect GPIO13 i.e D7 to one end of resistor
  • Connect another end of resistor to Positive terminal of Buzzer
  • Connect GND of ESP8266 to GND of the Buzzer

ESP8266 Code

Please upload the following code in ESP8266.

  int value = 0;
  int past=0;
  void setup()
    // Motion sensor is connected to D5 pin of ESP8266
    pinMode(14,INPUT); //COnfigured as input
    //Buzzer is connected to D7 pin of ESP8266
    pinMode(13,OUTPUT); //Configured as ouput
    Serial.println("please connect sensor to D5 pin of ESP8266");
    Serial.println("please connect D7 pin of ESP8266 to resistor");
  void loop()
    value=digitalRead(02); //reads movement data from pir sensor
    if(value==1 && past==0)
    digitalWrite(13,HIGH); //Turn on buzzer
    if(value==0 && past==1)
    digitalWrite(13,LOW); //Turn off buzzer

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