CDR
EDWARD NICHOLSON
KAREEM NAMMARI
WES STANWAY
KARI SKUPA
CUI SUN
RECAP
• Measures vibrations resulting from sound
waves.
• Designed for covert surveillance but has
other uses.
EDWARD
PROBLEMS
• Lab access
– Need sponsorship
• Optics
– Alignment
– Expensive
• Lasers
– Safety
EDWARD
ACCOMPLISHMENTS
• Basic photodiode
– Viewed a distorted version of original signal
• Working sound box
– Aquarium with speakers
• A/D Converter
– Confirmed capability
– Stores digital signal
EDWARD
LOW GOALS
•Basic bounce at an angle configuration
•Replay Signal
•Basic Filtering
EDWARD
MEDIUM GOALS
• Identify audio source through DSP (FFT)
• Store audio signal
• Terminal Control
EDWARD
HIGH GOALS
•
•
•
•
Interferometry configuration
LCD Display
FFT signal analysis directly on board
Wireless signal communication
EDWARD
SOFTWARE FUNCTIONAL DECOMP
Microprocessor
I/O
Embedded Software
LEDs
Hardware
Interrupts
ADC
Read
USB
Intel x86
Software
Matlab
A/D
Converter
Hardware
Buttons
Hard Memory
Audio Out
EDWARD
HARDWARE FUNCTIONAL DECOMP
INTERFEROMETER
LASER
DETECTOR
ANALOG
FILTERS
A/D
CONVERTER
MICROPROCESSOR
OPTICS
SELECTOR /
MUX
AUDIO
MEMORY
SOFTWARE
AMPLIFIER
AUDIO
SOURCE
I/O
AUDIO OUT
USB
HARDWARE
POST PROCESSING
POWER
TERMINAL
LASER!
±15 V
MATLAB
+3.3V
SUN
POWER
Wall Wart
• 12 V DC
• 1-2 A
SUN
3.3V RAIL
• Powers the microprocessor
• Can be powered by either USB or Wall
wart
• RS232RL chip
SUN
± 10V RAIL
• MUX
• OpAmps
SUN
LASER DRIVER
• Adjustable intensity
• Power the laser
SUN
OPTICS
• Interferometery is on the backburner.
• Focusing on Bounce System
• Mounting
– Rail
– Board
– Tripods
KAREEM
FILTERS
• All Filters are Active
• Bessel Filters
– Maximally flat group delay
– All filters are second order
• Antialiasing Filter
– 4th order Butterworth
– Very sharp cutoff
– Phase delay not particularly important
KAREEM
7KHZ LPF
KAREEM
20KHZ LPF
KAREEM
60HZ HPF
KAREEM
AA FILTER
KAREEM
OP-AMPS
• Op-Amps are LMP7704
– Low Noise
– Wide Supply Range
– High Bandwidth
– Quad Package
• 14 Pin SOIC Narrow
KAREEM
DETECTOR
• Using a BPW21R photodiode for bounce
– Detects light between 450nm and 700nm
• Detection speed is not particularly
important
– No need to bias the photodiode
– Sensitivity is increased when photodiode is
unbiased
• Gain can be adjusted easily
KAREEM
WES
WES
WES
WES
MCU: MSP430F5438
•
•
•
•
•
•
LCD capability
20 MHz clock speed
256 kB of flash memory
16 kB of SRAM
12-bit ADC
87 GPIO pins
KARI
ADC SAMPLING
• Able to sample at 44,100 Hz
• Can read amplitude of a signal
• Can store amplitude data on chip
KARI
SOFTWARE INTERFACE
• Post-processing in MATLAB
– DSP and FFT
• Terminal communication
• I/O interface
– 8 LEDs
– 3 buttons
– USB
– Audio jack out
KARI
DIVISION OF LABOR
Kari
Sun
Cole
Wes
Kareem
Software
Power
Software
Layout
Optics
Digital
Hardware
Optics
Digital
Hardware
Power
Analog
Hardware
Sound Box
Analog
Hardware
Sound Box
Populate
Board
Detector
Optics
Populate
Board
Populate
Board
Full Schematic
Budget
KARI
BUDGET
Block
Estimated Cost
Laser
$50
Optics
$250
PCBs
$120
Digital
Components
$150
Analog
Components
$200
Power
$100
Demo Box
$75
Expo Materials
$75
UROP Funding
-$1000
Total
-$80
KARI
SCHEDULE
KARI
MILESTONE GOALS
Milestone I
• Populated board
• Basic analog reading
• Tested power supplies
Milestone II
• Revised board layout
• Populated the revised board
• Working prototype
KARI
EXPO GOALS
• LCD display
• Data storage
• On-box options
– Fourier analysis
– Filter selection
– Output on display
KARI