Obstacle Detecting Glasses Lecture Notes

Overview

• Obstacle Detecting Glasses: Designed for visually impaired individuals.
• Components: Ultrasonic distance sensor and buzzer.
  • Measures distance to objects in front; buzzer beeps faster as objects get closer.
• Purpose: Enhances obstacle detection while walking, beyond traditional canes.

Functionality

• Cane Integration: Ultrasonic sensors can also be mounted on canes.
  • Best for ground-level obstacles.
  • Limited in detecting higher obstacles (e.g., tree branches, tables).
• Glasses vs. Canes: Glasses detect obstacles at face level, allowing for hands-free operation.

Construction Details

• Components Used:
  • Safety glasses with electronics mounted using double-sided foam tape or electrical tape.
  • Arduino Uno (chosen for educational purposes, ideal for beginners).
  • Ultrasonic distance sensor.
  • Buzzer.
  • 9-volt battery and power switch (barrel jack connector).
• Considerations:
  • Arduino Uno is larger but commonly used for educational projects.
  • Smaller Arduino options can be used for a more compact design.

Alternative Feedback Method

• Buzzer: Can be switched for a vibration motor for tactile feedback instead of audio.

Circuit Overview

• Parts List and Diagram: Available in the video description.
• Circuit Configuration: No breadboard required; parts connect directly to Arduino.
  • Ultrasonic Sensor (HC-SR04):
    • VCC: Connected to 5V.
    • Trig: Connected to pin 6.
    • Echo: Connected to pin 7.
    • Ground: Connected to ground.
  • Buzzer:
    • Negative lead: Ground on Arduino.
    • Positive lead: Pin 11.

Code Overview

• Key Code Elements:

  • Constants for connected pins.
  • Threshold variable for distance (in cm) to start beeping.
  • Delay variables for controlling beep speed.
  • Receive pulse return time and calculate distance in cm.

• Setup Function: Configures input/output for buzzer and ultrasonic sensor.

• Loop Function:

  1. Send trigger pulse to activate sensor.
  2. Read return pulse duration and convert to distance.
  3. Beeping Logic:
     • If distance < threshold:
       • Use Arduino map function to adjust beep speed based on distance.
       • Digital write to turn buzzer on/off depending on distance.
     • If distance >= threshold:
       • Buzzer is off.

Resources

• Full Project Information: Available in the video description and on the website: sciencebuddies.org.
• Other Projects: Over a thousand projects in various fields of science and engineering available online.