Musical Carpet ENSC 440 project Team Danny Jiang

Musical Carpet ENSC 440 project

Team Danny Jiang Anthony Tsang Department: Payam Norouzi Anton Ayzikovsky Software Division: Hardware

Agenda Project Description Motivation Roles System Overview Project Details Future Work Lessons Learned Questions

Project Description Step-sensitive Musical CARPET Sound-emitting Visually appealing With pitch detection capability

Motivation Fun Educational Aesthetically pleasing Awesome! Employs many principles learned

Roles Danny – sound engineer, software guru, time-management wizard, documentation master Anthony – voice recognition specialist, components researcher, relaxation supervisor Payam – wood cruncher, LED solderer, design maniac Anton – head carpetenter, sensor investigator, chief wiring officer

System Overview Main Control Audio Processing Sensors Display Module

Sensor Unit Main part of the sensor unit is the carpet Drawing: Carpet in production:

Sensor construction Each sensor consists of five contacts for best step detection Sensor structure: Sensors in production:

Sensor - Possible Solutions Sensor Piezoelectric Capacitive Proximity Strain Gauge Contact Switch Carpet Hand-made Purchased

Main Unit Sample sensor switches using polling method Sample voice data from microphone to perform FFT for pitch detection Communicate with Audio Processing Unit Interaction with display unit Record/playback feature

Main Unit - Microcontroller Atmega 64 53 general purpose I/Os 4 KB of internal SRAM 8 external Interrupt Atmega 32 general purpose I/Os 2 KB of internal SRAM 4 external Interrupts

Main Unit Atmega 64

Audio Unit Play sound samples from SD card Able to generate multiple tones at the same time Able to drive an 8 ohms speaker without external power

Audio Unit - High Level Diagram External SD Card SPI Speaker MCU DAC High Current Op. Amp

Audio Unit – Current state and Limitation Current State: Two channels Limitation: Small capacity of internal SRAM Access speed to SD card When many channels are playing at the same time, adding all samples together will lead to saturation

Audio Unit Arduino + Wave shield

Possible Solutions Main Unit PIC controller FPGA Audio Unit DSP Processor

Pitch Detection Sampling rate of 4 KHz Conversion to frequency domain with FFT Compares fundamental frequencies Component frequency ratio algorithm

Possible Solutions Time domain analysis Cepstrum Peak detection

Display Unit Storage for Other Components Push Buttons to change the modes LEDS

Business Case Just a piano shaped carpet Cost for a 3 by 4? $33 Pitch Detection Capability? With similar functionality Starts from $120 Mass Produced Carpet $0. 8 per square foot Atmega 64 6001+ $7. 6400 Control Board approximately $10 Other $20

Cost Breakdown Item Proposed Actual Difference Microprocessor Development kit $200. 00 $232. 60 ($32. 60) Electronic Components + LED x 10 $120. 00 $26. 32 $93. 68 Carpet material + Pressure Sensor x 10 $200. 00 $71. 42 $128. 58 Control board $0. 00 $31. 19 ($31. 19) Balance $520. 00 $361. 53 $158. 47 Funding $520. 00 $375. 00 $145. 00

Development Milestones

Further Improvements Software Combine the circuitry into one board Improve the pitch detection algorithm Use external RAM for better quality sound and playing more channels simultaneously Use full-swing amplifier for microphone circuitry Hardware Add LCD to the display unit for more functionality Use pressure sensors to vary the sound intensity Use single power supply with possible battery operation

Lessons Learned Technical Audio/Signal processing Communication protocols Hardware design Non-Technical Teamwork Conflict Resolution Project Management

References http: //www. aliexpress. com/product-gs/237703985 Piano-shape-handmade-carpet-120 -85 cmwholesalers. html http: //www. globalconvention. ca/ http: //avnetexpress. avnet. com/store/em/EMControll er? lang. Id=1&store. Id=500201&catalog. Id=500201&term=atmega 64 &x=0&y=0&N=0&action=products http: //www. digs. com/cool-music-carpet-humanantenna-by-florian-krautli/

Questions