The Smart Blind Stick is an active Electronic Travel Aid (ETA) designed to upgrade a traditional passive walking cane into a smart, obstacle-detecting device. Powered by an Arduino UNO, it utilizes ultrasonic echolocation to sense immediate obstacles in a user's path, providing real-time, graduated multi-sensory feedback (haptic and acoustic).
This project aims to provide an affordable, highly reliable, and zero-configuration safety tool for the visually impaired, allowing for confident and independent mobility.
- Instant Echolocation Feedback: Processes distance calculations in microseconds with zero-lag response.
- Graduated Acoustic Alerts: A piezo buzzer increases its beep rate as obstacles get closer (dynamic mapping between 11 cm to 100 cm).
- Haptic Warning System: A vibration motor activates in the critical zone (<= 10 cm) to provide physical "STOP" feedback.
- Reduced Haptic Fatigue: The vibration motor remains inactive during safe walking, activating only for close-range emergencies.
- Zero-Configuration Accessibility: Simple toggle switch operation. No Bluetooth, apps, or calibration required.
| Component | Description |
|---|---|
| Arduino UNO | The central processing microcontroller running the C++ logic. |
| HC-SR04 Ultrasonic Sensor | Primary obstacle detection eye (fires 40 kHz sound waves). |
| Water Sensor Module | Detects wet floors/puddles to prevent slips. |
| Piezo Buzzer | Emits high-frequency acoustic warnings. |
| Flat Vibration Motor | Delivers haptic feedback to the user's palm. |
| 9V Battery & Clip | Portable power supply with SPST Rocker Switch. |
| Jumper Wires & Breadboard | For circuit routing and prototyping. |
| Component | Pin / Terminal | Arduino UNO Pin |
|---|---|---|
| HC-SR04 Sensor | VCC | 5V |
| GND | GND | |
| TRIG | Digital Pin 8 | |
| ECHO | Digital Pin 9 | |
| Piezo Buzzer | Positive (+) | Digital Pin 6 |
| Negative (-) | GND | |
| Vibration Motor | Positive (+) | Digital Pin 2 |
| Negative (-) | GND | |
| Power Supply | Battery Positive | Vin (via Rocker Switch) |
| Battery Negative | GND |
- Detection: The HC-SR04 sends a 10µs pulse, triggering an 8-cycle ultrasonic burst. The Arduino calculates the returning echo's duration.
- Calculation:
Distance = (Echo Duration * 0.034) / 2(converted to centimeters). - Action:
- > 100 cm: Path clear. Buzzer OFF, Vibrator OFF.
- 11 cm - 100 cm: Approaching object. Buzzer beeps (interval scales dynamically from 500ms down to 50ms).
- <= 10 cm: Critical stop. Vibrator ON.
The embedded logic code is written in C++ for the Arduino IDE without relying on heavy external libraries to ensure fast, predictable execution.