Capstone Fall 2005 GFX-One Guitar Processor Team Carpal Tunnel September 8, 2005

Capstone Fall 2005 Team Members Mason Stone Mason Stone Henock Negassa Henock Negassa Tony Sawyer Tony Sawyer Nael Cassier Nael Cassier

Capstone Fall 2005 What is GFX-One? GFX-One is a digital audio effects processor. GFX-One is a digital audio effects processor. It is designed specifically for use with guitar, but can process any monaural analog audio input. It is designed specifically for use with guitar, but can process any monaural analog audio input.

Capstone Fall 2005 Functional Block Diagram

Capstone Fall 2005 Digital Signal Processor

Capstone Fall 2005 Why use a DSP? Digital data is easier to manipulate Digital data is easier to manipulate Implementing effects can be done using algorithms and subroutines as opposed to sophisticated analog hardware Implementing effects can be done using algorithms and subroutines as opposed to sophisticated analog hardware DSP can be altered and maintained using software DSP can be altered and maintained using software

Capstone Fall 2005 Implementing Audio Effects Flanger effect is present in a lot of guitar-driven music Flanger effect is present in a lot of guitar-driven music It is accomplished by adding a signal to a time-varying, phase-modulated version of itself It is accomplished by adding a signal to a time-varying, phase-modulated version of itself

Capstone Fall 2005 Fixed Delay and Reverberation Reverberation and echo are very common in audio engineering Reverberation and echo are very common in audio engineering Both can be synthesized in DSP using comb filters and re-circulating delay lines Both can be synthesized in DSP using comb filters and re-circulating delay lines

Capstone Fall 2005 Other Effects and Features Parametric Equalization Parametric Equalization Gain manipulation Gain manipulation Auto-Wah Auto-Wah Phaser Phaser Noise-gating Noise-gating Decimation (Aliasing) Decimation (Aliasing) Many other possibilities Many other possibilities

Capstone Fall 2005 DSP Interface What We Need: What We Need: –25 MHz Oscillator –Flash Microcontroller –256 MB SDRAM –FPGA –I/O

Capstone Fall MHz Oscillator Used to synchronize digital circuitry. Used to synchronize digital circuitry. With use of PLL, provides clock speed. With use of PLL, provides clock speed. Will be connected to FPGA, then distributed. Will be connected to FPGA, then distributed.

Capstone Fall 2005 Flash Microcontroller Contains instructions for DSP. Contains instructions for DSP. Internal μcontroller programs chip automatically over HDD interface. Internal μcontroller programs chip automatically over HDD interface. Internal code can contain image for FPGA. Internal code can contain image for FPGA.

Capstone Fall 2005 SDRAM/FPGA Operate over system bus: Operate over system bus: –8 bits for Address –8 bits for Data –Chip Enable –Read/Write Enable –Clock –IRQ

Capstone Fall 2005 Input/Output DSP means Digital Signal Processor, so we need a digital input and output. DSP means Digital Signal Processor, so we need a digital input and output. –A/D converter translates signal into DSP. –D/A converter translates signal out of DSP. DSP has Multi-channel Audio Serial Ports (McASP) to accomplish this, but it can also be implemented using parallel interface. DSP has Multi-channel Audio Serial Ports (McASP) to accomplish this, but it can also be implemented using parallel interface.

Capstone Fall 2005 Mixed Signal Interface Signal from Analog amplifier is fed to A/D Converter. Signal from Analog amplifier is fed to A/D Converter. Converts input voltage from analog signal in to Digital bit Converts input voltage from analog signal in to Digital bit Synchronized with 44.1KHz Clock Synchronized with 44.1KHz Clock 16 Bit digital signal 16 Bit digital signal

Capstone Fall 2005 Mixed Signal Interface Digital to Analog (D/A) conversion methods Digital to Analog (D/A) conversion methods –Data is fed from DSP to D/A Converter. –Standard D/A converters translate an array of digital bits into a bias voltage –Synchronized with 44.1KHz Clock –16 Bit digital signal

Capstone Fall 2005 Power Regulated 3.3 and 2.5 V power buses from 9V DC adapter. Regulated 3.3 and 2.5 V power buses from 9V DC adapter. 5V 5V –LCD 3.3 V 3.3 V –Compact Flash –A/D and D/A converters –Data lines to and from FPGA 2.5 V 2.5 V –FPGA Vcc

Capstone Fall 2005 Analog Signal Mixer A good recording mixer lets you route a variety of input signals and combine them into one signal. A good recording mixer lets you route a variety of input signals and combine them into one signal. For a potential Add-on output signal from MP3 player will mix with signal from D/A converter For a potential Add-on output signal from MP3 player will mix with signal from D/A converter

Capstone Fall 2005 Audio Op Amps Audio Op Amps Analog signal from Mixer is going to be amplified and routed to speaker Analog signal from Mixer is going to be amplified and routed to speaker Amplifier is transistor based Amplifier is transistor based 1.6- to 3.6-volt speaker driver 1.6- to 3.6-volt speaker driver

Capstone Fall 2005 Field Programmable Gate Array Gateway of the user to all the other chips Gateway of the user to all the other chips Controls the Clock to other devices Controls the Clock to other devices Sends data to the DSP as well as the LCD Sends data to the DSP as well as the LCD Flash will set the FPGA through the DSP Flash will set the FPGA through the DSP Program the FPGA through a JTAG Interface Program the FPGA through a JTAG Interface

Capstone Fall 2005 User Interface

Capstone Fall 2005 Schedule

Division of Labor NameTask Nael Cassier User Interface/FPGA Configuration Mason Stone DSP Integration Tony Sawyer DSP Core Implementation Henock Negassa A/D Component Integration

Capstone Fall 2005 Tentative Budget Component Manufacturer / Part Number Estimated Price Digital Signal Processor TI part # TMS320C6713 $100 FPGA Development Board Xilinx Spartan3 # XC3S200 $300 Flash Microcontroller Microchip # PIC16LF74/P $60 Flash PROM Xilinx # XC18V02 $50 SDRAM Micron #MT48LC16M16A2 $50 A/D Converter TI # ADS1625 $60 D/A Converter TI$60 25 MHz Oscillator $40 LCD Display Crystal Fontz #CFAH0802A $50 Printed Circuit Boards Advanced Circuits $200 Push-Button User Interface $45 Passive Components / Fixtures J.B. Saunders $200 9 V Power Supply J.B. Saunders $35 Analog Signal Mixer $100 Miscellaneous (printing/binding costs, posters, unforeseen parts, add-ons, etc) $250 Total$1600

Capstone Fall 2005 Possible Add-ons Add another analog signal (MP3) Add another analog signal (MP3) Amplifier + Speaker Amplifier + Speaker Over Drive Circuit Over Drive Circuit

Capstone Fall 2005 Risks and Contingencies Hardware Availability/ Damage Hardware Availability/ Damage Difficulties Implementing FPGA Difficulties Implementing FPGA Difficulties Implementing LCD Difficulties Implementing LCD Difficulties With DSP Interface Bus Difficulties With DSP Interface Bus

Capstone Fall 2005 Questions?