SMART Shower

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SMART Shower

• Robert Hobbs
• Bert Moore
• Courtney Pennington
• Bob Sokoloski
• ECE 4894/CEE 4804 - Section RPK-Group K1
• May 6, 2005

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Outline

• Design Engineering to Propose
• Prototype Development
• SMART Shower
• Introduction and Application Courtney Pennington
• Theoretical Physics Bert Moore
• Identifying Characteristics Bob Sokoloski
• New Product Robert Hobbs

3
Introduction

• Real World Problems With Current Showers
• All Current Options Must Be Set Manually

4
Application

• Solution
• Integrate fingerprint sensor
• Automatically read data from microprocessor
• Temperature set according to the next-to-last
  clocked, full minute, average temperature
• Data settings matched with fingerprint

5
Application

• Solution
• 1. No Data Is Matched With Fingerprint
• Scans index finger
• Shower automatically turns on with default
  temperature
• Can adjust default to desired temperature
• Microprocessor reads data
• Turn off shower
• Data matched with fingerprint

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Application

• Solution
• 2. Data Is Matched With Fingerprint
• Scan index finger
• Shower automatically turns on with desired
  temperature set previously
• Can adjust previous temperature
• Microprocessor reads data
• Turn off shower
• Data matched with fingerprint

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Block Diagram SMART Shower Design
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Application

• Fingerprint sensor
• FPS200 capacitive fingerprint sensor
  manufactured by Veridicom

http//www.veridicom.com/siliconfingerprint.html
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Theoretical Physics

• Capacitive sensor
• 2-D array
• Metal electrodes in sensing array
• Plates of capacitor
• Each metal electrode
• Contacting finger
• Passivative layer on device
• Dielectric between plates
• Ridges/valleys yield values across array
• Discharge voltages read to form image

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Theory Block Diagram
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Theory Fingerprint Sensor

• Sensor array
• 256 columns and 300 rows of sensor plates
• 2 sample-and-hold circuits for each column
• Image sensed one row at a time

• Example Fingerprint

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Theory Row Capture

• 2 phases of row capture
• Sensor plates of selected row are precharged to
  VDD voltage
• Internal signal enables first set
• of sample-and-hold circuits
• to store the precharged
• plate voltages of the row

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Theory Row Capture

• 2 phases of row capture
• Row of sensor plates discharge with current
  source
• Cell discharge rate proportional to discharge
  current
• Internal signal enables second set of
  sample-and-hold circuits to store final plate
  voltages
• Capacitance of sensor cell Precharged plate
  voltage Discharged plate voltage

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Theory Generation of Image
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Theory Generation of Image

• Capacitive fingerprint scanners
• Generate image of ridges/valleys
• Electrical current
• Sensor composed of
• Semiconductor chips
• Array of tiny cells
• Each cell
• 2 conductor plates covered with insulating layer

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Theory Capacitive Sensor

• Sensor connected to integrator
• Inverting op amp alters supply voltage
• Feedback loop connected to op amp output
• Includes conductor plates
• Form the capacitor

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Theory Fingerprint Sensor Operation

• To scan finger
• Processor closes rest switch for each cell
• Shorts each amplifiers input and output
• Balances integrator circuit
• Switch opened again
• Processor applies a fixed charge to IC
• Capacitors charge up
• Capacitance of feedback loop
• Affects voltage at amplifiers input
• Affects amplifiers output voltage

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Theory Fingerprint Sensor Operation

• Distance to parts of the fingerprint alters
  capacitance
• Cridge gt Cvalley
• Processor reads voltage output
• Determines whether ridge or valley
• Every cell in sensor array read by processor
• Compose overall image of fingerprint
• Compared to previous images collected

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Characteristics

• System Performance Characteristics
• System Flexibility
• Critical Performance Characteristics

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System Performance Characteristics

• Home Automation Controller
• IBM Compatible PC Based
• Water Temperature Sensor
• Pipe Mounted
• Handle Position Sensor
• Water Temperature Adjustment
• Fingerprint Sensor

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System Flexibility

• Operational Modes
• Manual
• Learning
• Programmed

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Modes

• Manual
• Normal Shower Operation adjusting temperature
  using handle
• Learning
• Water temperature, time, and handle position data
  collected/processed by controller/CPU
• Allows users to change shower profile
• Disregards temperature changes without associated
  handle position changes

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Modes

• Programmed
• Fingerprint data to controller/CPU
• User shower profile of temperature as a function
  of time initiated shower begins
• Temperature position handle manually overrides
  programmed profile to stop shower

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Critical Performance Characteristics

• Communication Pathway
• Controller output and inputs using RS232 or X10
  serial communication formats
• Multiple DPDT relays for controlling sensor logic

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New Product Using This Sensor

• SMART Shower Design
• Creative Product
• Application address by well-engineered,
  sensor-based product
• New product based on current sensor technology

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Need/Desire For SMART Shower

• Conservation
• Convenience
• Personalization
• Luxury

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Similar Products

• All manually set with digital interface
• Mr.Steam
• Manually set by user
• Inconvenient
• Lack of personalization
• Not conservative

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Manufacturing/Material Costs

• FPS Fingerprint Sensor 40 in 1000 unit
  quantities
• Microcontroller 5
• Temperature Sensor 15
• Position Sensor 25
• Manual Shower Temperature control (rotary knob)
  10

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Costs and Profits

• Total Cost 95
• Profit
• Depending on popularity of product
• Retail (recommended) 200
• Total households 100,000
• Chatham, Effingham, Bryan
• 10 of households 10,000
• Profit 1,050,000

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Benefits to Society

• Conserve water
• Personalization
• SMART home emergence
• Alleviate stress/aggravation
• Comfort/Luxury

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References

• http//www.veridicom.com/siliconfingerprint.html
• http//computer.howstuffworks.com/fingerprint-scan
  ner.htm
• http//www.veridicom.com/pdfs/FPS.pdf
• http//www.findarticles.com/p/articles/mi_m0EIN/is
  _2000_Sept_11/ai_65127048
• http//www.elecdesign.com/Articles/Print.cfm?Artic
  leID4226
• http//realiden.com/solu_pro/fps.html
• http//www.kroeker.net/published/graphics_and_secu
  rity.htm
• http//products.ecommerce-guide.com/security/biome
  trics/1089907341.html
• http//www.snet2000.com/download/1iguard6.pdf
• http//www.savcvb.com/savannah/population.shtml

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QUESTIONS???