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👟 SmartStep: A Smart Shoe for the Blind Using LiDAR and ESP32

A low-cost, wearable assistive tech project that helps the visually impaired detect obstacles using real-time audio alerts over Wi-Fi — no apps or internet required.

5/10/2025Arduino

▶ TL;DR - Watch a Video

🧠 The Problem and Solution Motivations

Accessibility technology should be built in by default.

With SmartStep, we aimed to assist the visually impaired by developing a wearable obstacle avoidance system using affordable components. No app. No Bluetooth. Just a smart shoe that connects to a user’s phone and streams real-time auditory alerts over Wi-Fi.

📌 Functionality It Performs

SmartStep is a shoe-based system that:

  • Detects obstacles using LiDAR
  • Hosts a Wi-Fi network via ESP32
  • Plays alert sounds through the user’s phone browser

No internet or mobile app is required. The entire system runs through a direct ESP32 Wi-Fi connection with the user’s handheld device.

🛠️ Materials Used

  • ESP32 — Handles processing and Wi-Fi audio serving
  • TF-Mini LiDAR Sensor — For accurate distance measuring
  • Rechargeable battery pack

🔄 The Process

Obstacle Detection

The TF-Luna Mini sensor continuously scans for objects within a ~2.5 meter range.

ESP32 Wi-Fi Serves Audio

The ESP32 runs a minimal HTTP server. When a phone connects and accesses the server’s IP, it plays sounds based on how close the nearest object is.

Command System

  • BLOCKED → Object within 10 cm → frantic notification
  • PLAY_SOUND → Object between 10–250 cm → distance-based beeping
  • STOP_SOUND → No object → silence

Client-Side Audio Playback

A lightweight JavaScript web page fetches the current state and plays or pauses audio accordingly.

⚠️ Challenges We Faced

  • Autoplay restrictions on mobile browsers (especially iOS)
  • Audio desynchronization due to noisy sensor data — solved with debounce logic
  • Battery life optimization to ensure long-lasting, wearable use

🌍 Accessibility Applications

This system can be extended to:

  • Smart white canes that inform users of blocked paths
  • Backpacks that detect obstacles above shoulder level
  • Wheelchair or walker aids for proximity awareness

👥 Team Credits 💡

Built by a group of passionate students in the accessibility tech space:

💬 Closing Thoughts

SmartStep proves that successful assistive technology doesn’t require a massive budget or complex hardware. With a microcontroller, one sensor, and a few clever lines of code, we’ve taken a meaningful step toward safe and smart mobility for everyone.