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Team 3 Piano Glove. ECE 477 Fall 2012 - Design Review. Mihir Shah Jonathan Kuntzman Carolyn McMican Daniel Stein. Outline. Project overview Project-specific success criteria Block diagram Component selection rationale Packaging design Schematic and theory of operation
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Team 3Piano Glove ECE 477 Fall 2012 - Design Review Mihir Shah Jonathan Kuntzman Carolyn McMicanDaniel Stein
Outline • Project overview • Project-specific success criteria • Block diagram • Component selection rationale • Packaging design • Schematic and theory of operation • PCB layout • Software design/development status • Project completion timeline • Questions / discussion
Project Overview • Piano Glove: Play virtual keyboard on any flat surface • 2 Components: Glove and Base Station • Glove collects finger pressure and stretch data, preprocesses data, transmits wirelessly to base • Base receives data, tracks position of glove on keyboard, outputs sounds for keys pressed
Project Specific Success Criteria • An ability to quantify the position of the glove relative to the processing unit. • An ability to combine finger press data and glove position to determine which virtual key has been pressed. • An ability to utilize SpeakJet from GPIOs to produce various sounds. • An ability to collect analog data from force and stretch sensors, digitize it, and correctly format packets for wireless transmission. • An ability to detect different pressure levels to control volume.
Component Selection RationaleOverview of Design Constraints • User Interface • Perform pressure measurements on fingertips • Perform spacing measurements between each finger • Perform distance measurements to locate position of glove • Digitize the measured analog signals • Transmit digitized data to Base Station via RF wireless signals • Microcontrollers • Fast clock speed to perform real time data processing ( ≤ 50ms ) • Memory for programming application • Convenience • Energy efficient to maximize battery life on Glove Unit • Minimize package size and weight for player comfort
Component Selection RationaleSensing & Positioning • Force Sensors Interlink FSR 400 • Able to detect pressure from 0.2N to 20N • Continuous resolution • Stretch Sensors Images SI Flexible Stretch Sensor • 60-70mils diameter • Initial release brings sensor to +10% of its resting value • Ultrasonic Beacon Parallax PING))) • Detection range from one inch to ten feet • Resolution of one centimeter • Narrow acceptance angle
Component Selection RationaleMicrocontrollers • Glove Microcontroller PIC24FJ64GA306 • 16 ATD converters • 2 SPI • Ultra low power operation • Maximum operating speed: 32MHz • Operating voltage: 2.0V to 3.6V • Flash programmable memory: 64KB • Base Station Microcontroller PIC18F87K90 • 2 SPI • Maximum operating speed: 64MHz • Operating voltage: 1.8V to 5.5V • Flash programmable memory: 128KB
Component Selection RationaleWireless Transceivers • Wireless Transmitter & Receiver Nordic nRF2401A • Single chip transceiver with small footprint • Ultra low power operation • Data transmission up to 1Mbps • Operating voltage: 1.9V to 3.6V
Packaging Design • Small, Thin Circuit Board • Light Weight • Comfortable to Player • Stay attached during Quick Movement
Packaging Specifications • Gloves (without parts) • Weight 25g • Gloves (with Parts) • Weight 80g • Includes sensors, battery, microcontroller, Bluetooth module • HUB • Weight ~150g • Length 7 inches • Width 3 inches • Height 5 inches
Packaging Design Forehand View Backhand View
Packaging Design Base Station Package
Schematic Base Station
Base Station To5V DC Wall Wart LEDs 3.5mm AudioJack Optic Isolator Amplifier Power Supply
Base Station To5V DC Wall Wart LEDs 3.3V Voltage Regulator Power Supply 5V Voltage Regulator
Base Station Wireless Receiver • Reset • Microcontroller • SpeakJet
Base Station • Microcontroller • LCD • Ultrasonic • Beacon
Base Station • Microcontroller • SpeakJet
Base Station 3.5mm AudioJack Optic Isolator Amplifier
Schematic Glove
Glove Unit Power Supply LEDs Sensors
Glove Unit 4.5V Battery Supply LEDs 3.3V Voltage Regulator
Glove Unit Wireless Transmitter • Reset • Microcontroller • Programming • To Optic Isolators
Glove Unit • Sensors & Optic Isolators
Glove Unit • Optic Isolators • To Sensor • To PIC
Theory of OperationInterlink FSR 400 Resistance vs. Force • Able to detect pressure from 0.2N to 20N • Continuous resolution
Theory of OperationImages SI Stretch Sensor • 1000ohm per linear inch • 60 – 70mils diameter • Stretched 50% 2 × initial R • Initial release +10% resting R
Theory of OperationParallax PING))) • One GPIO • Signal from microcontroller to release chirp • Sound is reflected off player’s hand • Listens for echo, when echo is heard, pulse is set low • Range from one inch to ten feet
PCB LayoutOverall Considerations • Keep analog outputs/inputs separate from digital circuitry • Transceivers and Ultrasonic sensor on edge of board • Glove: Fit on back of hand 3.8in x 2.6in • Base: 3.5mm jack on edge of board, needs cutout • Base: components mounted on box top need connections
Analog Base Station Digital Power Supply
Base Station Wireless Receiver
Analog Glove Unit Digital Power Supply
Analog Glove Unit Digital
Glove Unit Wireless Transmitter
PCB LayoutMicrocontroller Considerations • Decoupling Caps < 6mm (0.25in) from micro • Supply voltage traces should pass through caps before pins • Signals to header routed on underside of board to reduce congestion around micro • Keep paths to critical components (transceivers, ultrasonic beacon) short
Base Station • PIC18F87K90
Glove Unit • PIC24FJ64GA306
PCB LayoutPower Supply Considerations • Traces wider more current in this portion of circuit • Input and output filtering caps placed near power supplies
60mils Glove Unit 10mils 80mils 40mils Distance between Traces ≥ 12mils
Software Design • Glove Main Loop • Will be interrupt driven • Constantly checking A to D • Send finger press and stretch data • Base Main Loop • Will be interrupt driven • Constantly checking distance of glove • Interpret data into the keys pressed • Use Speakjet to generate appropriate sounds
Flowchart for Glove Start Has a key been pressed? No Yes Transmit data to base
Flowchart for Base Start Find Glove Position Data packet received? Output data to Speakjet Decode data into notes pressed Yes No