Team 3

Piano GloveECE 477 Fall 2012 - Design Review

Mihir Shah Jonathan Kuntzman Carolyn McMican Daniel Stein

OutlineProject overview Project-specific success criteriaBlock diagramComponent selection rationalePackaging designSchematic and theory of operationPCB layoutSoftware design/development statusProject completion timeline

Questions / discussion

Project OverviewPiano 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 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 DesignSmall, Thin Circuit Board

Light Weight

Comfortable to Player

Stay attached during Quick Movement

Packaging SpecificationsGloves (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 DesignForehand

ViewBackhand

View

Packaging DesignBase Station Package

Schematic

Base Station

Base Station

Base Station

Power Supply

LEDs

To 5V DCWall Wart

Optic Isolator

Amplifier

3.5mmAudio Jack

Base Station

Power Supply

LEDs

To 5V DCWall Wart

3.3V Voltage Regulator

5V Voltage Regulator

Base Station

Microcontroller

WirelessReceiverReset

SpeakJet

Base Station

LCD

Microcontroller

UltrasonicBeacon

Base Station

SpeakJet

Microcontroller

Base Station

Optic Isolator

Amplifier

3.5mmAudio Jack

Schematic

Glove

Glove Unit

Glove Unit

Power Supply

SensorsLEDs

Glove Unit

3.3V Voltage Regulator

LEDs

4.5V Battery Supply

Glove Unit

Microcontroller

WirelessTransmitter

To Optic Isolators

Reset

Programming

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

Base Station

Digital

Analog

Power Supply

Base Station

Base StationWireless

Receiver

Glove Unit

Glove Unit

Digital

Analog

Power Supply

Glove Unit

Digital

Analog

Glove Unit

Wireless Transmitter

PCB LayoutMicrocontroller ConsiderationsDecoupling 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

Base Station

Glove Unit

80mils

60mils

10mils

40milsDistance between Traces ≥ 12mils

Software DesignGlove 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 presse

d?

Transmit data

to base

Yes

No

Flowchart for BaseStart

Find Glove Position

Data packet receive

d?

Decode data into notes pressed

Output data to Speakjet

Yes

No

Projected Completion Timeline

Parts Received Oct. 16

PCB Complete/Submitted Oct. 19

Preliminary Software Written Oct. 26

Preliminary Packaging Parts Arrive Oct. 31Hardware/Software Interface using Dev Board Nov. 9

PCB Assemble Complete Nov. 16

Project Complete Nov. 30

Questions?