### Project 29: Intrusion Detection

![](media/b7828b9e5ee615a151567e20d35db90f.png)

**Description**

In this experiment, we use a PIR motion sensor to control an active buzzer to emit sounds and the onboard LED to flash rapidly.

**Required Components**

![image-20231020085335159](media/image-20231020085335159.png)


**Connection Diagram**

![](media/07ded8ae2b9b12d7d399422cae6b8c5a.png)

**Test Code**

```c
//**********************************************************************************
/*  
 * Filename    : PIR alarm
 * Description : PIR control buzzer
 * Auther      : http//www.keyestudio.com
*/
int item = 0;
void setup() {
  pinMode(15, INPUT);  //PIR motion sensor is connected to GPIO15 and set as the input mode
  pinMode(4, OUTPUT);//The active buzzer is connected to GPIO4 and set to output mode
  pinMode(22, OUTPUT);//LED is connected to GPIO22 and set to output mode
}

void loop() {
  item = digitalRead(15);//Read digital level signal output by infrared pyrorelease sensor
  if (item == 1) {  //Movement detected
    digitalWrite(4, HIGH); //Turn on the buzzer
    digitalWrite(22, HIGH); //Turn on the LED
    delay(200);//Delay 200ms
    digitalWrite(4, LOW); //Turn off the buzzer
    digitalWrite(22, LOW); //Turn off the LED
    delay(200);//Delay 200ms
  } else {  //No detection
    digitalWrite(4, LOW); //Turn off the buzzer
    digitalWrite(22, LOW); //Turn off the LED
  }
}
//**********************************************************************************
```



**Test Result**

Connect the wires according to the experimental wiring diagram, compile and upload the code to the ESP32. After uploading successfully，we will use a USB cable to power on. If the sensor detects people moving, the buzzer will emit an alarm , and the LED will flash continuously.