Introduction

Visually impaired people face many challenges while walking, especially due to obstacles, pits, and water on roads. A Smart Blind Stick is an assistive device designed using sensors and microcontrollers to help blind people detect obstacles and navigate safely.

The system uses ultrasonic sensors, water sensors, and buzzers to alert the user through sound or vibration.

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Objective of the Project

• To assist visually impaired people in safe navigation
• To detect obstacles in front of the user
• To detect water or wet surfaces
• To provide real-time alerts

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Working Principle

1. Ultrasonic sensor continuously measures distance
2. If an obstacle is detected within a preset range, the buzzer activates
3. Water sensor detects water or wet surfaces
4. Microcontroller processes sensor data
5. Alerts are given via buzzer or vibration motor

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Components Required

• Arduino Uno / Nano
• Ultrasonic Sensor (HC-SR04)
• Water Sensor
• Buzzer
• Vibration Motor (optional)
• Resistors
• Jumper Wires
• Battery / Power Supply

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Block Diagram

Ultrasonic Sensor + Water Sensor
            ↓
        Arduino
            ↓
     Buzzer / Vibration

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Circuit Connections

Ultrasonic Sensor (HC-SR04)

VCC  → 5V
GND  → GND
Trig → D9
Echo → D10

Water Sensor

S → A0
+ → 5V
- → GND

Buzzer

+ → D8
- → GND

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Arduino Code (Smart Blind Stick)

#define trigPin 9
#define echoPin 10
#define buzzer 8
#define waterSensor A0

long duration;
int distance;
int waterValue;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzer, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  waterValue = analogRead(waterSensor);

  if (distance < 60) {
    digitalWrite(buzzer, HIGH);
  } else if (waterValue > 500) {
    digitalWrite(buzzer, HIGH);
  } else {
    digitalWrite(buzzer, LOW);
  }

  delay(200);
}

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Code Explanation

• Ultrasonic sensor detects obstacles
• Distance is calculated using echo time
• Water sensor detects wet surfaces
• Buzzer alerts the user instantly

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Advantages

• Simple and low-cost solution
• Real-time obstacle detection
• Portable and lightweight
• Easy to use

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Applications

• Assistance for visually impaired people
• Smart wearable navigation devices
• Elderly care systems

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Future Enhancements

• GPS navigation and voice guidance
• Mobile app integration
• AI-based object detection
• SOS emergency alert feature

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Conclusion

The Smart Blind Stick provides an effective, affordable, and reliable solution to assist visually impaired individuals. With real-time obstacle detection and alert mechanisms, it significantly improves mobility and safety.