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.
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 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 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
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
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
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
Your consent to our cookies if you continue to use this website.