Master On-Device AI: Build an Offline Voice-Controlled Light Switch with ESP32 & Relay

Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.

Imagine controlling your room lights with nothing more than your voice—and doing it without any internet connection, cloud subscription, or privacy concerns. This kit puts you at the center of on-device machine learning, letting you build a fully local voice-controlled relay switch that instantly responds to commands like “lights on” and “lights off.” All processing happens right on the ESP32, so your voice never leaves the room.

What You'll Build

You'll assemble a complete voice-activated switching system. The ESP32 captures high-fidelity audio through an I2S MEMS microphone, runs a trained keyword spotting model from Edge Impulse, and triggers a 5V relay to control real appliances. An OLED display provides immediate visual feedback—showing recognized commands and device status. The whole unit works offline with zero latency.

What You'll Learn

• Train a keyword spotting model in Edge Impulse and deploy it to an ESP32.
• Interface an I2S MEMS microphone for clean, low-noise audio input.
• Drive a 5V relay module safely to switch AC loads (with flyback diode protection).
• Display real-time command results on a 0.96-inch OLED via I2C.

Kit Contents

Why Buy This Kit Instead of Sourcing Parts Separately

Who This Kit Is For

Ideal for CBSE Class 11-12 students exploring practical AI, B.Tech ECE/EEE learners building voice interfaces, and Smart India Hackathon teams prototyping privacy-first IoT solutions. It’s also a strong fit for ATL Tinkering Lab students ready for advanced speech recognition, and engineering students at IIT, NIT, VIT, or BITS adding on-device ML to their capstone projects.

Built and Backed by Compoden

Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.