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 1)An ability to quantify the position of the glove relative to the processing unit. 2)An ability to combine finger press data and glove position to determine which virtual key has been pressed. 3)An ability to utilize SpeakJet from GPIOs to produce various sounds. 4)An ability to collect analog data from force and stretch sensors, digitize it, and correctly format packets for wireless transmission. 5)An ability to detect different pressure levels to control volume.

Block Diagram

Component Selection Rationale Overview 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 Rationale Sensing & 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 Rationale Microcontrollers Glove Microcontroller  PIC24FJ64GA 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 Rationale Wireless 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 ViewBackhand View

Packaging Design Base Station Package

Schematic Base Station

Power Supply LEDs To 5V DC Wall Wart Optic Isolator Amplifier 3.5mm Audio Jack

Base Station Power Supply LEDs To 5V DC Wall Wart 3.3V Voltage Regulator 5V Voltage Regulator

Base Station Microcontroller Wireless Receiver Reset SpeakJet

Base Station LCD Microcontroller Ultrasonic Beacon

Base Station SpeakJet Microcontroller

Base Station Optic Isolator Amplifier 3.5mm Audio Jack

Schematic Glove

Glove Unit

Power Supply Sensors LEDs

Glove Unit 3.3V Voltage Regulator LEDs 4.5V Battery Supply

Glove Unit Microcontroller Wireless Transmitter To Optic Isolators Reset Programming

Glove Unit Sensors & Optic Isolators

Glove Unit Optic Isolators To Sensor To PIC

Theory of Operation Interlink FSR 400 Resistance vs. Force Able to detect pressure from 0.2N to 20N Continuous resolution

Theory of Operation Images SI Stretch Sensor 1000ohm per linear inch 60 – 70mils diameter Stretched 50%  2 × initial R Initial release  +10% resting R

Theory of Operation Parallax 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 Layout Overall 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

Base Station

Digital Analog Power Supply Base Station

Wireless Receiver

Glove Unit

Digital Analog Power Supply

Glove Unit Digital Analog

Glove Unit Wireless Transmitter

PCB Layout Microcontroller 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 Layout Power Supply Considerations Traces wider  more current in this portion of circuit Input and output filtering caps placed near power supplies

Base Station

Glove Unit 80mils 60mils 10mils 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 Yes No

Flowchart for Base Yes No

Projected Completion Timeline Parts ReceivedOct. 16 PCB Complete/SubmittedOct. 19 Preliminary Software WrittenOct. 26 Preliminary Packaging Parts ArriveOct. 31 Hardware/Software Interface using Dev BoardNov. 9 PCB Assemble CompleteNov. 16 Project CompleteNov. 30

Questions?