ESP32 PIR Motion with Arduino IDE

Introduction

The PIR (Passive Infrared) sensor detects motion by sensing changes in infrared radiation.
It outputs a digital HIGH signal to the ESP32 when motion is detected, and LOW when idle.
Commonly used in security systems, motion-activated lights, and automation projects.
In this tutorial, we’ll connect a PIR sensor to the ESP32 and detect motion events.

Required Components

• ESP32 Board
• PIR Motion Sensor
• Jumper wires
• Breadboard (optional)

Pinout

Circuit Diagram / Wiring

• PIR VCC → 5V (ESP32)
• PIR GND → GND (ESP32)
• PIR OUT → 14 (ESP32)

Code / Programming

#define PIR_Pin 14  // Use GPIO14 or any other available digital pin

void setup() {
  Serial.begin(115200);           // Use a higher baud rate for ESP32
  pinMode(PIR_Pin, INPUT);        // Set PIR pin as input
  Serial.println("PIR Sensor Initialized");
}

void loop() {
  int val = digitalRead(PIR_Pin); // Read PIR sensor value

  if (val == HIGH) {
    Serial.println("Motion Detected");
  } else {
    Serial.println("No motion detected.");
  }

  delay(1000);  // Delay for stability
}

Explanation

• The PIR sensor detects motion by sensing changes in infrared radiation from moving objects.
• It sends a HIGH signal to ESP32 when motion is detected and LOW when idle.
• ESP32 reads this digital signal to trigger actions like alerts, lights, or automation tasks.

Troubleshooting

• If motion is never detected, wait 30–60 seconds after powering up for the PIR sensor to stabilize.
• Ensure the OUT pin is connected to a proper digital GPIO, like GPIO14 (avoid boot-sensitive pins like GPIO0, 2, or 15).
• If false triggers occur, adjust the PIR sensor’s sensitivity and delay knobs to filter out noise.