SBS — Smart Blind Stick

SBS (Smart Blind Stick) is an assistive technology prototype designed to help blind and visually impaired people detect obstacles while walking.

The system uses an HC-SR04 ultrasonic sensor to detect obstacles within a 1-meter range and provides audio feedback through a buzzer. The closer an obstacle gets, the faster the buzzer alerts the user.

Goal: Use affordable and accessible electronics to develop a simple technology that can support safer and more independent mobility.

---

Features

• Obstacle detection up to 1 meter
• Audio warning using a buzzer
• Real-time distance measurement
• Faster alerts as obstacles get closer
• Programmed using Arduino IDE
• Simple and affordable hardware
• Designed as an assistive technology prototype

---

Built With

• NodeMCU ESP8266 — Main microcontroller
• HC-SR04 Ultrasonic Sensor — Distance and obstacle detection
• Buzzer — Audio feedback
• Arduino IDE — Programming environment
• C++ / Arduino — Programming language

---

Hardware Connections

Component	NodeMCU Pin
HC-SR04 TRIG	D5
HC-SR04 ECHO	D6
Buzzer +	D2
Buzzer −	GND
HC-SR04 GND	GND
HC-SR04 VCC	VIN / 5V

Important

The HC-SR04 Echo pin can output approximately 5V, while the ESP8266 GPIO operates at 3.3V.

Use an appropriate voltage divider or level shifter between the HC-SR04 Echo pin and NodeMCU D6 to protect the ESP8266.

---

How It Works

The HC-SR04 sends an ultrasonic pulse toward the environment. When the pulse encounters an object, it reflects back to the sensor.

The NodeMCU calculates the distance using the time taken for the echo to return.

SBS then controls the buzzer according to the detected distance.

Alert Behavior

Distance	Buzzer Behavior
More than 1 meter	Silent
60–100 cm	Slow beep
30–60 cm	Faster beep
Less than 30 cm	Very fast beep

This allows the user to understand how close an obstacle is based on the frequency of the sound.

---

Project Structure

SBS-Smart-Blind-Stick/
│
├── src/
│   └── SBS_Smart_Blind_Stick.ino
│
├── README.md
├── LICENSE
└── .gitignore

---

Getting Started

1. Clone the Repository

git clone https://github.com/YOUR_USERNAME/SBS-Smart-Blind-Stick.git

2. Open the Project

Open the project folder using VS Code or Arduino IDE.

3. Install ESP8266 Board Support

Make sure ESP8266 board support is installed in Arduino IDE.

4. Connect the NodeMCU

Connect the NodeMCU ESP8266 to your computer using a USB cable.

5. Select the Board

In Arduino IDE, select the appropriate NodeMCU ESP8266 board and the correct USB/COM port.

6. Upload

Open:

src/SBS_Smart_Blind_Stick.ino

Then compile and upload the program to the NodeMCU.

---

Project Logic

          HC-SR04
             |
             v
      Measure Distance
             |
             v
       NodeMCU ESP8266
             |
       +-----+-----+
       |           |
   > 100 cm     <= 100 cm
       |           |
    No Alert    Activate
                 Buzzer
                    |
                    v
          Closer = Faster Beep

---

Project Objective

SBS explores how embedded systems can be used to create affordable and accessible assistive technology.

The project focuses on providing an additional way for users to become aware of obstacles ahead without requiring expensive equipment.

---

Accomplishments

• Successfully integrated an ultrasonic sensor with NodeMCU.
• Implemented obstacle detection within a 1-meter range.
• Developed distance-based buzzer alerts.
• Created a functional assistive technology prototype.
• Built the system using affordable and widely available components.

---

What We Learned

Through SBS, we gained practical experience with:

• ESP8266/NodeMCU programming
• Arduino IDE
• Ultrasonic distance measurement
• GPIO configuration
• Buzzer control
• Embedded C++
• Basic electronics
• Assistive technology development
• Hardware and software integration

---

Future Improvements

Future versions of SBS could include:

• Improved audio feedback
• Vibration feedback
• Multiple ultrasonic sensors
• Drop-off and hole detection
• Stair detection
• Rechargeable battery system
• GPS functionality
• Mobile application
• IoT connectivity
• Improved lightweight stick design

---

Disclaimer

SBS is currently an experimental prototype and should not be considered a certified safety or mobility device.

Real-world deployment should include extensive testing, reliability evaluation, accessibility testing, and safety validation.

---

Contribution

Contributions, ideas, and improvements are welcome.

If you would like to contribute:

1. Fork the repository.
2. Create a feature branch.
3. Make your changes.
4. Test your changes.
5. Submit a pull request.

---

License

This project is released under the MIT License.

---

About SBS

SBS — Smart Blind Stick

Technology with a purpose: building more accessible and inclusive solutions through innovation.