Published September 17, 2025 © GPL3+

Smart PIR Motion Light Control with WiFIRCard

Automate your lights with PIR motion sensing + WiFIRCard. ESP32-S3 powered, Wi-Fi ready, and dual-relay control in a credit-card size board.

IntermediateFull instructions provided2 hours31

Smart PIR Motion Light Control with WiFIRCard

Things used in this project

Hardware components

WiFIRCard

PIR Motion Sensor (generic)

Light Bulb with Holder

Wires

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Multitool, Screwdriver

Story

Ever fumbled for the light switch in the dark? With a PIR sensor and WiFIRCard — a tiny ESP32-S3 board with Wi-Fi, IR, and dual onboard relays — you can make your lights smart enough to switch on when you enter and off when you leave.

Its compact, credit-card size design makes it easy to drop into any DIY project, while built-in relays let you control appliances directly without extra modules. Simple, power-saving, and a fun way to explore home automation.

Wiring Connections :

We have to connect PIR motion sensor with board using GPIO and power pins. Also connect load like light bulb which we are interested to operate based on motion, you can change as per your applications. Follow below wiring connections,

1)Wiring connection for PIR Interfacing with WiFIRcard :

WiFIRCard Interfacing with PIR sensor

2)Wiring connection of Bulb/Load :For this connection you can use any one relay channel from two options available. For each relay there are three pins NO (Normally OPEN), NC (Normally CLOSED) and C (COMMON) for wiring electrical device.Relay 1 -> NO1, C1, NC1Relay 2 -> NO2, C2, NC2

Load Wiring Connection

WARNING:Electrical wiring should be installed or serviced only by a qualified professional. Improper handling may result in shock, fire, or injury.

Final connection Real View

Software Setup and Configuration

Install Arduino IDE

Go to Arduino Software Downloads.

Download the latest stable release (Arduino IDE 2.x) for your operating system.

Install it:

Windows: Run the .exe installer.
macOS: Drag the .app to Applications.
Linux: Extract the .tar.xz file and run install.sh.

Add ESP32 Board Support

Open Arduino IDE → File ➜ Preferences (Windows/Linux) or Arduino IDE ➜ Preferences (macOS).

In “Additional Board Manager URLs”, paste:

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

(If other URLs exist, separate them with a comma.)

1 / 2 • Select Preferences

Install the ESP32 Platform

Go to Tools ➜ Board ➜ Board ManagerSearch for esp32. Select “ESP32 by Espressif Systems” and click Install (or Update if prompted).

1 / 2 • Select Board Manager

Now, esp32 based boards installed. For confirmation we can check various ESP32 boards as below,

ESP32 Boards

Coding and Testing

Download or copy example provided in code section to Arduino IDE. We have to select suitable board for WiFIRCard, so choose ESP32 S3 Dev Module.Go to Tools ➜ Board ➜ ESP32 ➜ choose ESP32S3 Dev Module

ESP32S3 Dev Board for WiFIRCard

Now select suitable com port, here we have used native USB so you will get option as shown below. Also, enable USB CDC on Boot to monitor any data over serial port. Keep rest default and click upload button to transfer code.

1 / 2 • Select COM Port

Working

Finally testing motion detect and switching light ON if activated else switch OFF light.

PIR Motion Detection with WiFIRCard

PIR Motion with WiFIRCard code

// WiFIRCard with PIR Sensor interfacing and Relay Control
// PIR sensor output -> GPIO43
// Relay module input -> GPIO9

const int PIR_PIN   = 43;   // PIR sensor signal pin
const int RELAY_PIN = 9;    // Relay control pin

void setup() {
  Serial.begin(115200);
  
  pinMode(PIR_PIN, INPUT);       // PIR as input
  pinMode(RELAY_PIN, OUTPUT);    // Relay as output
  digitalWrite(RELAY_PIN, LOW);  // Start with relay OFF
  
  Serial.println("PIR + Relay setup complete.");
}

void loop() {
  int motion = digitalRead(PIR_PIN);

  if (motion == HIGH) {
    // Motion detected
    digitalWrite(RELAY_PIN, HIGH);    // Turn relay ON
    Serial.println("Motion detected: Relay ON");
  } else {
    // No motion
    digitalWrite(RELAY_PIN, LOW);     // Turn relay OFF
    Serial.println("No motion: Relay OFF");
  }

  delay(200); // Small delay to avoid rapid toggling
}

Credits

M. Brus

1 project • 0 followers

Maker at heart, educator by choice—simplifying electronics for everyone.

Smart PIR Motion Light Control with WiFIRCard

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Wiring Connections :

Software Setup and Configuration

Install Arduino IDE

Add ESP32 Board Support

Install the ESP32 Platform

Coding and Testing

Working

Code

PIR Motion with WiFIRCard code

Credits

M. Brus

Comments

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Smart PIR Motion Light Control with WiFIRCard

Smart PIR Motion Light Control with WiFIRCard

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Wiring Connections :

Software Setup and Configuration

Install Arduino IDE

Add ESP32 Board Support

Install the ESP32 Platform

Coding and Testing

Working

Code

PIR Motion with WiFIRCard code

Credits

M. Brus

Comments

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