Design and Implementation of an IoT-Based Smart Shoe with Blynk–Twilio Emergency Alerts to Enhance Independence of the Visually Impaired

Abstract

The work designs and implements a low-cost Internet of Things smart shoe to enhance safety and independence for visually impaired users by unifying ultrasonic obstacle sensing, Global Positioning System (GPS) geolocation, audio–haptic feedback, and multi-channel emergency alerts through Blynk and Twilio. The platform centers on an ESP32 microcontroller that interfaces with an ultrasonic sensor, a GPS receiver, an emergency push button, a buzzer, and a vibration motor. Firmware developed in the Arduino IDE parses GPS data and manages sensing, actuation, and cloud notifications. Functional verification under indoor and outdoor conditions evaluates threshold-based obstacle warnings and the end-to-end alert pipeline that delivers GPS-tagged push or email notifications and short message service (SMS). The prototype consistently triggered audio–haptic cues when distance fell below a 40 cm safety threshold and sent alerts with coordinates when the emergency button was pressed, demonstrating a coherent device-to-cloud-to-caregiver flow without reliance on vision-based sensing. The findings indicate that an ESP32–ultrasonic–GPS architecture with Blynk–Twilio alerts is feasible and replicable for assistive footwear, advancing user safety and independence while keeping complexity and bill of materials practical. Future development should add detection of holes and elevation changes, improve robustness in obstructed environments, and optimize energy use to extend operating time.