senior design i mid semester presentation october 9, 2014
DESCRIPTION
Problem/Market System Overview Review of Subsystems Progress Timeline OutlineTRANSCRIPT
Senior Design IMid Semester Presentation
October 9, 2014
John CornEE
Alex GibsonEE
Jordan KleinCPE
Shane ReevesEE – Team Leader
Dr. KoshkaTeam Advisor
Team
• Problem/Market• System Overview• Review of Subsystems• Progress• Timeline
Outline
• Guitar interfaced synthesizers are virtually nonexistent• No guitars with lasers on the market• Market towards all musicians
Economic Practical Constraint:The Guitar must not cost more than $500.
Market
• Microcontroller• Lasers• Power Supply• Fretboard Finger Positioning• Synthesizer
Systems
Device Pros Cons
Arduino Due -84MHz CPU speed-2 DAC I/O pins -12 Analog I/O pins
Arduino Mega2560 -Currently owned-16 Analog I/O pins - 16MHz CPU speed
Microcontroller
Audio Latency Technical Constraint:The processor must detect a broken beam and output sound within 50ms.
Photodiodes must detect light wavelengths between 500nm and 600nm.
Light Detection Technical Constraint:
Photodiodes
[2]
[2]
Lasers
[3]
30mW Green Laser ModuleWavelength: 532nmOperating Voltage: 3VOperating Current: 360mA
Health and Safety Practical Constraint:The laser beams must be safe to the touch under normal operational conditions.
Power Supply
[4]
Device Quantity Voltage Current Total Current ( Three Hours )Laser 12 3 V 360 mA 12960 mA
Microcontroller 1 7 - 12 V 50 mA 150 mA
Synthesizer 1 3.3 V 18 mA 54 mA
Battery 2 7.4 V 6600 mAh 13200 mAh
Fretboard Finger Positioning
Technology Pros Cons
Membrane Potentiometers
- Easy to implement- Stable operation
- Expensive ($25 x 6)- Not visually appealing
Capacitive Sensing - Visually appealing- Inexpensive
- Difficult to implement- Requires significant calibration
Laser Time-of-Flight - Visually appealing- Precise measurements - Extremely Difficult to implement
Capacitive Sensing
• A simple RC circuit is used
• One plate of the capacitor is formed by a metal contact on the guitar and the other plate is formed by the finger of the player
• The time it takes for the Receive pin to read HIGH after the Send pin has been set HIGH will vary based on changing capacitance
MetalContact
Player’sFinger
~
Capacitive Sensing
• A simple RC circuit is used
• One plate of the capacitor is formed by a metal contact on the guitar and the other plate is formed by the finger of the player
• The time it takes for the Receive pin to read HIGH after the Send pin has been set HIGH will vary based on changing capacitance
Capacitive Sensing
• The 22 frets on the guitar will be used as the metal contacts
• Capacitive sensing begins when a laser beam on the neck of the guitar is broken
How Does a Synthesizer work?
By combining multiple sine waves and adjusting amplitude, a synthesizer can create a new waveform.
Synthesizer
Synthesizer
Technology Pros Cons
Arduino Synth Library -Easy to implement-Open source -Limited Functionality
SAM2695 Synthesizer -Extensive sound library-Onboard effects -Difficult to implement
The SAM2695 has functions for 128 instruments that support over 100 notes.
This will function like a keyboard that has multiple instrumental settings.
Synthesizer – SAM2695
Capabilities:•64-voice polyphony (without effects)•38-voice polyphony + effects•On-chip CleanWave™ wavetable data, firmware, RAM delay lines
Synthesizer – SAM2695
Synthesizer – SAM2695
[6]
SAM2695 -Low power single chip synthesizer with effects and built-in codec
48 pin package
Synthesizer – SAM2695
What is a codec?
A codec takes data and compresses/decompresses it so it can be transferred/received faster.
DataData CodecCodec DataData
Progress
• Formulated overall approach
• Lasers and photodiodes ordered and received
• Capacitive sensing tested
• Laser detection via photodiodes tested
• SAM2695 synthesizer chip ordered
• Issue with laser overheating resolved
Progress – Overheating Lasers
Progress – Pulsing Lasers
Timeline
[1] Available:
http://arduino.cc/en/Products.Compare
[2] Available:
http://advancedphotonix.com/wp-content/uploads/PDB-C142.pdf
[3] Available:
https://www.dx.com/p/30mw-532nm-green-laser-module-3v-11-9mm-26888
[4] Available:
http://www.all-battery.com/li-ion1865074v6600mahrechargeablebatterymodulewithpcb.aspx
[5] Available:
http://makezine.com/projects/make-35/advanced-arduino-sound-synthesis/
[6] Available:
http://www.dream.fr/pdf/Serie2000/SAM_Datasheets/SAM2695.pdf
References
Senior Design IMid Semester Presentation
October 9, 2014