μ Sight

1. μSight Sumona Ray Richard Chen

2. Objective • To create a simplistic and cost effective system to provide a sense of imaging for the blind. • Reinvent the senses • Allow the visually impaired the ability to image their surroundings. • Color • Distance • Velocity

3. Benefits & Features • Provides a blind user with a new definition of color. • System is affordable compared to other solutions. • The device communicates distance, velocity, and color by means of various sound characteristics. Distance Volume Color Pitch Velocity Rate of Beep

4. Image Capture Device Proximity Sensor Color to Pitch Mapping Distance to Volume Velocity Reading Low Battery PIC18F4520 Battery (Power Supply for all Modules) Audio Output Battery Reg. Design Overview

5. Software • Used PIC18F4520 to integrate the various components • Analog-to-Digital converter in order to read sensor inputs • Audio controlled through PWM output • Serial output using MAX232N interface for verification and testing

6. Software – Audio Output • PWM controlled audio output • Rate controlled by specified wait times • Pitch range 895Hz to 485Hz • Avg. output voltage 2.5V to 50mV • OpenPWM1(pitch); • SetDCPWM1(output); • waitrate(rate);

7. Testing – Proximity Sensor • By use of a RC Filter, we are able to accurately read distance from 0 to 10 feet. • The sensor reads 9.8mV per inch.

8. Testing – Proximity Sensor

9. Software – Proximity & Velocity • Distance defined by volume and rate • 50mV - 2500mV average voltage • Required maximum of 100mV output voltage • Tweaked for appropriate sensitivity • 5 inch increments

10. Testing – Color Sensor • The photodarlington transistor consists of two bipolar transistors. • This configuration provides an extremely large internal current gain. • The light current is captured through the base and the associated voltage is outputted through the emitter.

11. Testing – Color Sensor • The following component testing was done with different colors of paper. • The light sensor outputs 4.3V for room light and .3V for darkness.

12. Software – Color to Pitch

13. Software – Analog Inputs • A/D converter to read in values from sensors • Values are then manipulated to adjust PWM output

14. Software – Serial Output

15. Battery Regulation Circuit • The purpose of this circuit is to output a logic high when the battery is above 6.4V and a logic low when the battery is below 6.4V. • The circuit operates essentially off a 6.2V Zener Diode. • This circuit interfaces with the PIC184520 so that only a 3 beep low battery indicator is heard by the user when low battery occurs.

16. Power Consumption • The 9V battery, which provides 400mAH, will be a sufficient as the battery will be drained after 28.6 hours of use. • Our final circuit operates at 126mW.

17. PCB Board & Housing • The PCB board focuses on modularity in order to make debugging easier. • The housing was made to tightly fit the board.

18. Software – Switches & Low Battery • Three enable switches, one for each module • Audio indicator for nothing enabled • Three beep indicator for low battery

19. Conclusive Thoughts Successes Challenges & Limitations • Modular • Low cost/Light weight • Fun to use • Different textures & environments • Alternate uses • Musical instrument • Image Capture Device Implementation • Light Sensor • Velocity Interpretation • Proximity Sensor Range • Debugging • PCB

20. Conclusive Thoughts Ethical Considerations Future Work • Audio volume • Mobility • Light sensor to define color • Size reduction • Longer range • Test subjects • Improved housing • User interface • Battery access

21. Questions