Transcript Final Presentation

P11003
Dynamic Keyboard Phase II
Dynamic Keyboard Phase III
5/13/2011
Andrew Hobson
Andrew Vitkus
Evan Gelfand
Sponsor: Dr. DeBartolo
Agenda
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Overview
Customer Needs and Engineering Specifications
Concept Selection
System Architecture
Mechanical/ Electrical Design Overview
Testing Results
Current State
Successes and Failures
Next Step
What would We Change?
Questions?
Dynamic Keyboard Overview
 Design and manufacture a
PC keyboard that will sense
key pressure
 Utilize Dynamic Keyboard,
Phase I, and Dynamic Keyboard
Phase II recommendations
Dynamic Keyboard Phase III
 Hand off Dynamic Keyboard, Phase III, so that
Phase IV will create software applications
Customer Needs and
Engineering Specifications
Customer
Need #
Description
Engr.
Spec. #
Specification
(description)
Unit of Measure
Ideal
Value
CN1
Ability to portray expression through
learned ability
ES1
Keystroke has tactile Feel
Boolean
Yes
CN2
Integration to PC through standard
connections
ES2
Individual keys will be
able to withstand at least
10N of force (2.25lbs)
Max force (N)
10
CN3
Ability to differentiate individual key
strike events, and associate them to
corresponding sensor events in time.
ES3
Total component costs
Dollars ($)
<1000
ES6
Force Response Range
Force (N)
2.5
CN4
Simple keyboard functionality
ES9
Precision of force sensor
% error
±5%
CN5
Must be reliable
CN6
Establish a high level of device precision
ES17
Keyboard drivers
-
Original
ES20
Type of PC Interface
Type
USB
CN7
Design or consider other keyboard
configurations for future teams
ES21
Paired Character Data
Boolean
Yes
Key Customer Needs
Key Engineering Specifications
Concept Selection
Concept Selection from MSDI
System Architecture Overview
User Input
Modified
Keyboard
System
Original
Keys
Feedback
Mechanism
Sensor
Martix
Internal
Frame
Hardware Casing
Mechanical
Stop
(threashold)
Sensor
Controller
Original
Keyboard
Membrane
Micro
Controller
Original
Controllor
System Architecture Block Diagram
USB Hub
PC
Assembly Overview
Fabricated Band
Modified Top Casing
Modified Bottom Casing
Custom PCB with Force Sensors
Fabricated Wedge
4-40 x 1” Screws
Dynamic Keyboard Exploded View
Mechanical Design Overview
 Chose SpecResearch K-558/U
keyboard for aesthetics, cost,
and space for electronics
 Used standard domes (not foam)
SpecResearch K-558/U
 Reversible construction
 Used standard size fasteners (4-40 x 1” SHCS)
Electrical Design Overview
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Single PCB design
USB interface
86 Pressure Sensors (Force Sense Resistor)
Implemented Arduino Nano MCU
2 RGB-LED provide feedback
Sends Key-Pressure paired data
Sampling frequency up to 60 Hz
Keyboard hardware interface API
Integrated with original keyboard hardware
Arduino Nano MCU
Testing Results Overview
 Mechanical Specifications: weight,
dimensions, cable length all
exceeded customer specifications
Custom Made Pressure Testing Fixture
 Electrical Specifications: signal delay,
sample rate, power required, controller
resolution, operating frequency met
or exceeded customer specifications
Pressure Testing Results
Pressure Sensor Data
180
160
140
Q
Output Value
120
t
p
100
\
80
z
b
60
Left Shift
40
Number Pad 1
20
Number Pad 9
0
50
100
150
200
250
300
350
400
Weight (g)
Graph of Key Pressure Testing Results
450
500
Current State
 Keyboard is built and operational
 Dual functionality
 Standard Keyboard
 Dynamic Keyboard
 LEDs provide visual feedback for
users
 Outputs Key-Pressure paired data
 Functional Keyboard software suite
Assembled Dynamic Keyboard Phase III
Successes and Failures
Successes
Failures
Able to communicate
between SolidWorks
and PCB Artist
Wedge had to be redesigned
Custom PCB/ keyboard
matrix alignments
Keyboard selection
Positive feedback at
ImagineRIT
F10, F11 buttons do
not function
Only one “spin” of
PCB required
Custom PCB and
FSRs took up
majority of budget
Extra FSRs left over
Mechanical Noise
Under budget
Dome placement
SolidWorks Top View of Pressure Sensors on PCB
Next Step
 Normalize sensor values
 Further develop controller API
 Develop software applications that utilize the keypressure data.
 Applications: text size and color change, shortcuts
to programs, enhanced passwords, shorthand
writing, autocorrect, gaming, ergonomics
Proposed Text Application
What Would We Change?
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Design smarter sensor matrix PCB configuration
Use brand name keyboard with single dome pad
Enhanced mechanical support
Use a microcontroller with faster ADC
Further develop software
Dome Pad
Perform more rigorous testing
Questions?