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ECE 477 Design Review FEST – Fall 2011. Outline. Project overview Project-specific success criteria Block diagram Component selection rationale Packaging design Schematic and theory of operation PCB layout Software design/development status Project completion timeline
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Outline • Project overview • Project-specific success criteria • Block diagram • Component selection rationale • Packaging design • Schematic and theory of operation • PCB layout • Software design/development status • Project completion timeline • Questions/discussion
Project overview • Automated system for testing speakerphones • Delivers • test signals • pre-recorded audio • Used to determine • time delay • frequency response • Records audio output from DUT
PSSC • An ability to measure time delay response between project’s components; the playback device, the telephone line simulator, the DUT which is the speakerphone, and the receiving device. • An ability to determine the frequency response of the DUT. • An ability to “play back” sound files. • An ability to record audio and write it to non-volatile (removable) memory. • An ability to perform duplex testing of recording data and playing back data.
Component selectionrationale • TMS320F-28035 MCU • 80 pin count, 128KB on-chip Flash • ANSI C language • 60 MHz • 2 - SPI, 1- SCI, 1 – I2C • 14 PWM and 16 ATD
Component selection rationale • TLV320AIC23 Audio Codec • 8 – 96 KHz sampling up to 24-bit depth • Stereo Channel
Component selection rationale • LCD – 09568 • SCI/SPI interface • Programmable baud rate • 20 x 4
Packaging design • Back • Power switch • Reset button • Power jack • Power LED • Side • SD Card • RJ11
Project Packaging • Front • Microphone • XLR • ¼” • Speaker • TOP • LCD • 4 Push Buttons
Top Left Front
Theory of Operation Power Management • Power rails of 3.3 V and 5.0 V needed. • Two voltage regulators will be used for getting the desired power rails.
Theory of operation SD Card • Operating Voltage - 3.3V • Interfaced using SPI module. • Run at 15 Mhz (Maximum supported by SPI moudle) • Will be used to read and write audio files.
Theory of Operation LCD • Operating Voltage – 5.0V • Interfaced using SCI module. • Run at 9600 Baud rate • Will be used to implement a simple user interface. • 20 x 4
SchematicTheory of Operation • MCU • SPI
SchematicTheory of Operation • MCU • I2C – Used to program the codec
MAIN (MCU and Power) • MAIN PCB Includes: • 5V and 3.3V Regulators (LT1086) • TI Microcontroller (TMS320F28035) • Transceiver (MAX3221) • Digital Isolator (ISO7221A) • 14-pin Header • SD Card Header (M11) • JTAG • Power Jack “Wall wart”
Codec (and other) • CODEC PCB Includes: • Codec (TLV320AIC23B) • 3.5mm Audio Jacks (Microphone & Speaker) • Data Access Arrangement device (CH1840) • Microphone Preamplifier (MAX4063) • Simple 6-pin RJ11 Jack • Potentiometer • 14-pin Header • 5V and 3.3V Regulators (LT1086)
Software designDevelopment status • Interrupt-driven software • Interrupt generated by Timer module for accurate task transition • Each interrupt causes MCU to switch task and spoon-feed necessary modules with data (SPI, SCI, I2C, etc.) • Buttons also generate interrupt • Same repetitive tasks until test is stopped or SD card is full • Remaining CPU time for signal processing math
SOFTWARE DESIGN DEVELOPMENT STATUS • Out-of-reset • Display menu • Check SD card status • Display test options • Begin test • Measure time delay • Measure frequency response • Any other pre-programmed tests • Free-run test until SD card is full
Questions Please Don’t ask any…