sock puppet sensors

Download Sock Puppet Sensors

Post on 08-Jul-2015




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Sock puppet mouth angle sensor for modulating voice playback with gestures.


  • 1. PUPPETS WITH VOICESNATALIE FREEDMAS 836 SPRING 2011Thursday, August 25, 2011

2. APPLICATION PICK UP A PUPPET AND MOVE ITS MOUTH TO PLAY BACK YOUR RECORDED VOICE. EACH PUPPET HAS ITS OWN VOICE, MODIFYING YOUR OWN. IT SHOUTS IF YOU MAKE BIG MOUTH MOVEMENTS, WHISPERS IF YOU MAKE SMALL ONES. SPEED OF MOUTH MOVEMENT CHANGES SPEED OF PLAYBACKThursday, August 25, 2011 3. APPROACHES 1. CAPACITIVE SENSING - LOADING MODE 2. ELECTRIC FIELD SENSOR / CAPACITIVE SENSING - TRANSMIT-RECEIVELoading Mode (measure I ) Single Electrode No cable to electrode No contact with electrode Couples to everything 3-object geometry Hard to adjust sens. area => Hard to do tracking Used for everything Can focus w. tomograpy- Stud finders (pre MIR)=> Add more transceiversTheremins, buttons...REFERENCES [1]Thursday, August 25, 2011 4. LOADING MODE CIRCUITLOADING MODERELAXATION OSCILLATOR + VOLTAGEFOLLOWER + BUFFER WITH OFFSETThursday, August 25, 2011 5. LOADING MODEBUILD PROCESS IRONING FUSIBLE CONDUCTIVE FABRIC TO THICK FELTThursday, August 25, 2011 6. LOADING MODEBUILD PROCESSGROUND SENSINGSHIELDING ELECTRODEThursday, August 25, 2011 7. LOADING MODE BUILD PROCESS SEWING LEADS TO ELECTRODE, SHIELDING, AND GROUNDThursday, August 25, 2011 8. LOADING MODEBUILD PROCESSSEWING SENSORS INSIDE THE PUPPETThursday, August 25, 2011 9. LOADING MODE RESULTSONCE HAND IS IN PLACE, RANGE IS TOO SMALL(ABOUT 2 INCHES) AND OUTPUT IS NOT LINEAR.EFFECTIVELY MEASURES VERY SMALLMOVEMENTS (FROG PUPPET) BUT NOT LARGE(WHALE PUPPET).Thursday, August 25, 2011 10. TRANSMIT/RECEIVE CIRCUITtransimpedanceamplifier (inverting) active high pass filter with10 pFamplification(inverting)1MOhm transmit receive 0-500KO electrode electrodeVCC hmsVCC envelope LC circuit follower -125kHz pulsetuning cap+20K-TLV2374 Ohms 6.8 nF+ TLV2374ATMEGA32~47pF6.8 nF1M OhmU4 (Teensy) VCC5K ADC OhmsVbias = 2.5V5K Ohms 1. 125kHz 0 to 5V square wave from ATMEGA to 100V PTP sine wave from resonant circuit. 2. output of transmit electrode received as current on receive electrode. 3. transimpedance amplifier turns current into changing voltage signal 4. high pass filter with (adjustable) amplification reduces noise, raises level to 0-5V for ADC 5. envelope follower turns signal into DC voltage for ADC to readThursday, August 25, 2011 11. TRANSMIT/RECEIVEMICROCONTROLLER CODE Using Teensy (ATMEGA32 U4) but cant use Arduino compiler because it hogs the timers! The square wave ends up looking like this: Instead, use just C/AVR and turn off the other timers, this fixes it. Use 16-bit timer/counter 1 to generate square wave:ISR(TIMER1_OVF_vect){TCNT1=0xFFD9; // set initial timer/counter value (16 bit counter)PORTB ^= _BV(PORTB2); //toggle pin B2}Thursday, August 25, 2011 12. TRANSMIT/RECEIVE BUILD PROCESSOp-Amp test board on breadboard(beware when moving breadboard toprotoboard, changes in capacitance)vinyl-cut electrodesPockets to hold boards in correctRound protoboards from Radioshack alignment to each other and makeboards removableThursday, August 25, 2011 13. TRANSMIT/RECEIVE RESULTSHTTP://VIMEO.COM/28166293Thursday, August 25, 2011 14. SOFTWARE(WORK IN PROGRESS)Thursday, August 25, 2011 15. SOFTWAREP-TO-P AMPLITUDE OF OSCILLATION OF PUPPET MOUTHAFFECTS GAIN. WHICH PUPPET IS CHOSEN AFFECTS PITCH.Thursday, August 25, 2011 16. RESOURCES 1. CAPACITIVE SENSING/ELECTRIC FIELD SENSOR LECTURE NOTES, JOE PARADISO (HTTPS://STELLAR.MIT.EDU/S/COURSE/MAS/SP11/MAS.836/ COURSEMATERIAL/TOPICS/TOPIC1/LECTURENOTES/CLASS6- EMSENSORS/CLASS6-EMSENSORS.PPT) 2. TEENSY REFERENCE - PJRC (HTTP://PJRC.COM/TEENSY/) 3. FABFISH (HTTP://BDM.CC/FABFISH/) 4. FILTERS/AMPLIFIERS REFERENCE (HTTP://WWW.ELECTRONICS- TUTORIALS.WS/FILTER/FILTER_6.HTML) 5. ATMEGA TIMER/COUNTERS (HTTP://WWW.ELECTRONICSBLOG.NET/ EXAMPLES-OF-USING-ARDUINOATMEGA-16-BIT-HARDWARE-TIMER-FOR- DIGITAL-CLOCK/MANY THANKS TO: BRIAN MAYTON, MARK FELDMEIER,DAVID CRANOR, NAN-WEI GONGThursday, August 25, 2011 17. Thursday, August 25, 2011