Musical%20Carpet

1
Musical Carpet

• ENSC 440 project

2
Team

• Danny Jiang
• Anthony Tsang
• Payam Norouzi
• Anton Ayzikovsky

Software Division
Hardware Department
3
Agenda

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

4
Project Description
Musical CARPET

• Step-sensitive
• Sound-emitting
• Visually appealing
• With pitch detection capability

5
Motivation

• Fun
• Educational
• Aesthetically pleasing
• Awesome!
• Employs many principles learned

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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

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System Overview

• Main Control
• Audio Processing
• Sensors
• Display Module

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Sensor Unit

• Main part of the sensor unit is the carpet

Drawing
Carpet in production
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Sensor construction

• Each sensor consists of five contacts for best
  step detection

Sensor structure
Sensors in production
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Sensor - Possible Solutions

• Sensor
• Piezoelectric
• Capacitive
• Proximity
• Strain Gauge
• Contact Switch

• Carpet
• Hand-made
• Purchased

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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

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Main Unit - Microcontroller
Atmega32
Atmega64

• 32 general purpose I/Os
• 2KB of internal SRAM
• 4 external Interrupts

• 53 general purpose I/Os
• 4KB of internal SRAM
• 8 external Interrupt

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Main Unit

• Atmega64

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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

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Audio Unit - High Level Diagram
External SD Card
SPI
Speaker
MCU
High Current OpAmp
DAC
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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

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Audio Unit

• Arduino Wave shield

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Possible Solutions

• Main Unit
• PIC controller
• FPGA

• Audio Unit
• DSP Processor

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Pitch Detection

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

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Possible Solutions

• Time domain analysis
• Cepstrum
• Peak detection

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Display Unit
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Business Case

• Just a piano shaped carpet
• Cost for a 3 by 4? 33
• With similar functionality
• Starts from 120

• Pitch Detection Capability?

• Mass Produced
• Carpet 0.8 per square foot
• Atmega64 6001 7.6400
• Control Board approximately 10
• Other 20

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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 x10 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
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Development Milestones
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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

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Lessons Learned

• Technical
• Audio/Signal processing
• Communication protocols
• Hardware design

• Non-Technical
• Teamwork
• Conflict Resolution
• Project Management

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References

• http//www.aliexpress.com/product-gs/237703985-Pia
  no-shape-handmade-carpet-120-85cm-wholesalers.html
  
• http//www.globalconvention.ca/
• http//avnetexpress.avnet.com/store/em/EMControlle
  r?langId-1storeId500201catalogId500201terma
  tmega64x0y0N0actionproducts
• http//www.digsdigs.com/cool-music-carpet-human-an
  tenna-by-florian-krautli/

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Questions