DIY Motion-Activated Lights That Talk to Alexa

Create fun, DIY motion-activated lights that interact with Alexa for a smarter home.

Posted by Nina Alvarez on April 17, 2025 · 5 mins read

DIY Motion-Activated Lights That Talk to Alexa

Have you ever walked through a dark hallway only to stumble over a shoe or fumble for the light switch? If you’re looking to enhance the functionality of your home while making things easier, setting up motion-activated lights that interact with Alexa is not just a great solution—it’s a fun DIY project! In this guide, I’ll walk you through how to create a system that automatically turns on lights when you enter a room and chats with you through your Amazon Alexa device. Let’s get started!

Step-by-Step Setup Guide

What You’ll Need

Before diving in, gather these components:

  • Amazon Echo device (Alexa)
  • Node-RED installed on your local server or Raspberry Pi
  • PIR motion sensor
  • Relay module or smart bulbs if your lights support it
  • Jumper wires and a breadboard (if using the PIR sensor and relay module)

Step 1: Set Up Node-RED

If you haven’t already, install Node-RED. Check out the Node-RED documentation for installation guidance.

Step 2: Connect the Motion Sensor

  1. Wire your PIR Sensor: Connect the VCC and ground pins of the PIR to the power supply. Connect the OUT pin to a digital input on your microcontroller (like a Raspberry Pi or Arduino).
  2. Connect the Relay Module: If you are using a relay, connect the IN pin of the relay to another GPIO pin. The relay will act as a switch for your lights.

Step 3: Configure Node-RED Flows

  1. Open Node-RED: Navigate to your Node-RED instance in the browser.
  2. Add Nodes: Start by adding an inject node to simulate the motion detected, a function node to check the state of the motion, and an execute node to control the relay or smart bulb. Finally, add an Alexa node using the node red contrib alexa home skill to send notifications.
  3. Configure the MQTT: If you’re using MQTT to handle the communication with the bulbs or relays, set up the MQTT nodes accordingly.
  4. Connect and Deploy: Wire these nodes together and click the “Deploy” button to save your flow.

Step 4: Voice Configuration with Alexa

  1. Enable the Alexa Skill: In the Alexa app, enable the skill for your motion-activated lights (from the Alexa app menu, find “Skills & Games”).
  2. Discover Devices: Use the command “Alexa, discover my devices.” This will allow Alexa to find and control your newly set-up motion lights.

Step 5: Test Your Setup

To test:

  • Walk in front of the motion sensor. The lights should turn on!
  • Ask Alexa about your lights—”Alexa, turn on (or off) the lights.”
  • Alternatively, you can set up custom routines with Alexa to enable even more functionality!

Helpful Tip Block

  • Positioning: Place your PIR motion sensor near entrances or commonly trafficked areas to maximize its effectiveness.
  • Sensitivity Adjustment: Many PIR sensors allow for sensitivity adjustments. Fine-tuning this can help prevent false positives.
  • Node-RED Tutorials: Familiarize yourself with Node-RED flows by exploring various node-red flow examples online.

Common Issues & Troubleshooting

Lights Don’t Turn On

  • Check Connections: Ensure all wiring connections are secure. Loose connections can prevent the system from working.
  • Node-RED Issues: Verify if the correct nodes are set up and have been properly deployed after any changes.

Alexa Doesn’t Recognize the Setup

  • Skill Missing: Double-check that you’ve enabled the right skill in the Alexa app.
  • Device Discovery: Perform a manual discovery using “Alexa, discover my devices” or check the Alexa app to see if your motion lights appear.

False Triggers

  • Calibration: If the lights activate too often, revisit the settings on your motion sensor. Adjust the sensitivity as needed.

Final Thoughts

Creating motion-activated lights that talk to Alexa not only enhances your home automation experience but also adds convenience to your daily life. Plus, tinkering with Node-RED allows you to learn more about IoT and custom solutions. With just a few components—and by following the steps outlined above—you can create an impressive smart lighting system.

Take the leap, and bring some magic to your home. When you finish, share your creation and experiences with the DIY Smart Home community. Happy automating!

← Previous Post Next Post →