Team 5Ergonomic Sensor for PC Users

Brian Dharmanto, Tam Hoang, Ahmed Almulhim, John Chhokar

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

Problem Definition Number one injury in the office is caused from

bad ergonomics. Companies have started to express a lot of

interest in ergonomics as employee lost day cases as increased.

Ergonomics in the workplace focuses on the health and well being of the employees.

Occupational Safety and Health Administration (OSHA) reports that improper viewing distances to the PC can cause eye strain that lead to headaches.

Problem Definition American Optometric Association (AOA) state

that 50-90% of PC users experience Computer Vision Syndrome (CVS).

CVS is defined as a temporary condition resulting from focusing the eyes on a computer screen for uninterrupted periods of time.

Motivation There is no device on the market that keeps

the PC user accountable for operating the PC at a proper viewing distance

The objective is to create such a device that keeps the PC user at a good distance and as a result reduce CVS.

We will focus only on distances which are too close.

Companies are looking at software to improve ergonomics but have yet to come up with a hardware solution

Objective Goal of the project is to design a working

prototype Secondly the design should be stable such

that the user is aware of a bad viewing distance as soon as they approach dangerous viewing distances.

Lastly, the prototype should be at least as small a standard wireless USB mouse.

Alternative Software: Flux : Change the

color of screen

Eye Defender: Remind user to take a rest after a given time

Screen Protector: Prevent direct expose to UV light

Requirement Place the ultrasonic on the top of the screen,

the sensor must look directly to face of user unless the device will send the incorrect warning.

Approach

6 steps : Research Sensor Microcontroller code Prototype Schematic & Layout Test

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

System Design

Zone Definitions Green Zone (Safe) : ~ > 18 inches Red Zone (Danger): ~ < 18 inches Green Zone Upper Bound: ~ 55 inches

State Machine

HardwareType: MicrocontrollerAtmega 328p5 volt operating voltage14 digital I/O pinsProgramming Language similar to CCheapNo debugging in code is only disadvantage

HardwareType: Sensor InputPING Ultrasonic Sensor5 volt operating voltageRelatively low costReliable results3 pin interface

HardwareType: Output LEDs2 diffused 10mm LEDs1 LED BarLow current Cheap

HardwareType: Speaker8 Ω, .1w powerPerfect for PCB BoardCompact and Light

Measure the distance The sensor emit a short 40Khz

burst then listen for echo.

This burst travel with velocity = 1130 feet/second, hit the object and bounce back

The sensor provide an output pulse to terminate when the echo is detected. Therefore, the width of this pulse correspond to the distance

Code Program

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

Schematic

Dimensions Board: 3.8inch x 2inch Allowed: 4inch x 3.2inch Altoids can: 3.5inch x 2.25inch

PCB Layout

Product Life Cycle

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

IP• Arduino Development Board http://www.arduino.cc/ - Used to upload software and debug

• Ping Sensor http://www.parallax.com/tabid/768/ProductID/92/Default.aspx - Datasheet discusses formulas to calculate distances

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

Testing

Stress Testing

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

Individual Contributors (Ics)Brian Dharmanto Schematic Board Component Solder

Ahmed Almulhim Component Solder Design of board case Prototype

Tam Hoang Software Hardware Design of sensor

case

John Chhokar Software Prototype Wiki Admin

Agenda Problem Definition The Design Implementation IP and Prior Work Testing and Results Contributions Lessons Learned

Lessons Learned Ahmed Tam - Software - Sensor Coding - Solder - Software - Case Design John Brian - SVN - PC BOARD Layout - WIKI - EAGLE - Case Design - SMT Solder

Project Schedule

DEMO