DIY Automatic Staircase Lighting with PIR Sensor

Project Overview

This project creates an automatic staircase lighting system that turns on LED strip lights when someone approaches the stairs and turns them off after a set delay. Perfect for improving safety on stairs at night while saving energy.

Difficulty: Beginner
Estimated time: 2-3 hours
Estimated cost: $25-35

How It Works

The system uses two PIR sensors placed at the top and bottom of the stairs. When a sensor detects motion, it triggers the LED strip to turn on. A microcontroller tracks which direction the person is moving and can optionally light only the relevant portion of the stairs. The lights turn off after a set period of no motion.

Materials Needed

• Arduino Uno or ESP32 (1)
• HC-SR501 PIR sensors (2) – one for top, one for bottom
• LED strip (5V or 12V, length to match your stairs) – WS2812B addressable or simple RGB strip
• MOSFET or relay module (if using 12V LED strip)
• 5V/12V power supply (depending on LED strip voltage)
• Jumper wires
• Project enclosure for Arduino (optional)
• Mounting brackets or adhesive tape for sensors and LED strip

Circuit Diagram

Connection Table (Arduino Uno)

Wiring Notes

If using a 12V LED strip, connect it to an external 12V power supply and use a MOSFET or relay module to switch it on/off. The MOSFET gate connects to an Arduino digital pin.

Arduino Code

// Automatic Staircase Lighting with PIR Sensors
// Uses two PIR sensors at top and bottom of stairs

const int topPIR = 2;
const int bottomPIR = 3;
const int ledPin = 6;        // For simple LED strip control
// For addressable LEDs, include the FastLED library

unsigned long lastMotionTime = 0;
const unsigned long lightTimeout = 10000; // 10 seconds

bool lightsOn = false;

void setup() {
  pinMode(topPIR, INPUT);
  pinMode(bottomPIR, INPUT);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  
  Serial.begin(9600);
  Serial.println("Staircase Lighting System Ready");
  Serial.println("Waiting 60 seconds for sensor warm-up...");
  delay(60000);  // Allow sensors to stabilize
}

void loop() {
  bool topDetected = digitalRead(topPIR) == HIGH;
  bool bottomDetected = digitalRead(bottomPIR) == HIGH;
  
  if (topDetected || bottomDetected) {
    // Motion detected - turn on lights and reset timer
    if (!lightsOn) {
      digitalWrite(ledPin, HIGH);
      lightsOn = true;
      Serial.println("Lights ON");
    }
    lastMotionTime = millis();
    
    // Optional: print direction
    if (topDetected && !bottomDetected) {
      Serial.println("Motion at TOP of stairs");
    } else if (bottomDetected && !topDetected) {
      Serial.println("Motion at BOTTOM of stairs");
    } else if (topDetected && bottomDetected) {
      Serial.println("Motion at BOTH ends");
    }
  }
  
  // Check if lights should turn off
  if (lightsOn && (millis() - lastMotionTime > lightTimeout)) {
    digitalWrite(ledPin, LOW);
    lightsOn = false;
    Serial.println("Lights OFF");
  }
  
  delay(100);  // Small delay to debounce
}

Code for Addressable LED Strips (WS2812B)

#include <FastLED.h>

#define LED_PIN     6
#define NUM_LEDS    20  // Change to match your strip length
#define BRIGHTNESS  64
#define LED_TYPE    WS2812B
#define COLOR_ORDER GRB

CRGB leds[NUM_LEDS];

const int topPIR = 2;
const int bottomPIR = 3;

unsigned long lastMotionTime = 0;
const unsigned long lightTimeout = 10000;
bool lightsOn = false;

void setup() {
  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(leds, NUM_LEDS);
  FastLED.setBrightness(BRIGHTNESS);
  
  pinMode(topPIR, INPUT);
  pinMode(bottomPIR, INPUT);
  
  // Turn off all LEDs
  FastLED.clear();
  FastLED.show();
  
  Serial.begin(9600);
  delay(60000);  // Sensor warm-up
}

void setLightColor(int startLED, int endLED, CRGB color) {
  for (int i = startLED; i <= endLED; i++) {
    leds[i] = color;
  }
  FastLED.show();
}

void loop() {
  bool topDetected = digitalRead(topPIR) == HIGH;
  bool bottomDetected = digitalRead(bottomPIR) == HIGH;
  
  if (topDetected || bottomDetected) {
    if (!lightsOn) {
      // Turn on all LEDs
      setLightColor(0, NUM_LEDS-1, CRGB::White);
      lightsOn = true;
    }
    lastMotionTime = millis();
  }
  
  if (lightsOn && (millis() - lastMotionTime > lightTimeout)) {
    // Fade out effect
    for (int b = BRIGHTNESS; b > 0; b -= 5) {
      FastLED.setBrightness(b);
      FastLED.show();
      delay(30);
    }
    FastLED.setBrightness(BRIGHTNESS);
    FastLED.clear();
    FastLED.show();
    lightsOn = false;
  }
  
  delay(100);
}

Installation Steps

1. Mount the sensors: Place one PIR sensor at the top of the stairs and one at the bottom. Mount them at 1.5-2m height, angled to cover the stair approach area.
2. Install LED strip: Attach the LED strip along the stair stringer, under the handrail, or along the stair treads. For best effect, mount under the handrail so light illuminates the steps without glare.
3. Run wiring: Connect sensors to the Arduino using 3-conductor cable. For long runs, use thicker wire (22 AWG or larger) to prevent voltage drop.
4. Power supply: Place the Arduino and power supply in a weatherproof enclosure near a power outlet. Ensure the power supply can handle the LED strip current (calculate: 60mA per LED for WS2812B).
5. Upload code: Connect Arduino to computer, upload the code, and test sensor function.
6. Adjust settings: Modify lightTimeout to change how long lights stay on. Adjust sensitivity pots on PIR sensors as needed.

Troubleshooting

• Sensor not detecting: Check wiring and ensure 60-second warm-up has completed. Adjust sensitivity potentiometer clockwise to increase range.
• False triggers: Ensure sensors aren’t facing heat sources (vents, windows). Reduce sensitivity or add a 0.1µF capacitor across VCC and GND near each sensor.
• Lights flickering: Power supply may be inadequate for LED strip current. Use a higher-rated power supply or reduce brightness in code.
• Sensor detects too far: Adjust sensitivity potentiometer counter-clockwise to reduce range.

Project Extensions

• Directional lighting: Light only the steps from the sensor that detected motion. This requires addressable LEDs and tracking which sensor triggered.
• Color temperature adjustment: Use warm white (2700K) at night, cooler white during the day using a real-time clock module.
• Smart home integration: Use an ESP32 instead of Arduino and integrate with Home Assistant or Alexa for remote control and scheduling.
• Music synchronization: Add a microphone module to make lights respond to music (great for parties).
• Motion-activated music: Add a DFPlayer Mini module to play a welcome message or music when motion is detected.

Conclusion

This automatic staircase lighting project improves safety and adds a modern touch to your home. The system can be installed in a weekend and customized to match your home’s decor. With proper installation, it will provide years of reliable service.