ECE 477 Design Review Team 5  Fall 2007 Wes Chris Josh Dave

Outline Project overviewProject overview Project-specific success criteriaProject-specific success criteria Block diagramBlock diagram Component selection rationaleComponent selection rationale Packaging designPackaging design Schematic and theory of operationSchematic and theory of operation PCB layoutPCB layout Software design/development statusSoftware design/development status Project completion timelineProject completion timeline Questions / discussionQuestions / discussion

Project Overview Wireless home media solutionWireless home media solution Consists of base station & portable media drivesConsists of base station & portable media drives Base station detects drives within rangeBase station detects drives within range Media files will be streamed from drives to base stationMedia files will be streamed from drives to base station Base station will output analog audio signal at line levelBase station will output analog audio signal at line level

Project-Specific Success Criteria 1.An ability to decode an MP3 file into a stereo, line-level analog output signal 2.An ability to read FAT16 files stored on an SD memory card 3.An ability to wirelessly transmit data from a plurality of handheld devices to a single base station 4.An ability to wirelessly detect active wireless handheld devices within close proximity and request MP3 files from them 5.An ability to display operational status on base station LCD

Block Diagram

Component Selection Critical componentsCritical components –Base station microcontroller –Portable drive microcontrollers –Wireless transceivers –Display –Portable drive batteries

Component Selection Base station microcontrollerBase station microcontroller –8-bit processor Maintain low costMaintain low cost More bits unnecessaryMore bits unnecessary –SPI port for four slaves LCD, mp3 decoder, wireless, flash memoryLCD, mp3 decoder, wireless, flash memory –General input/output pins At least 6 inputs for user controlsAt least 6 inputs for user controls At least 4 outputs for status LEDsAt least 4 outputs for status LEDs –Flash memory 9 KB for filesystem library9 KB for filesystem library 15 KB for application space15 KB for application space –2 KB RAM for filesystem buffering –Clock Preferably internal & programmablePreferably internal & programmable Minimum 5 MHz (128 x 2 kHz for SPI x 20 to be safe)Minimum 5 MHz (128 x 2 kHz for SPI x 20 to be safe) –“Reasonable” power consumption

Component Selection Base station microcontrollerBase station microcontroller –Atmel AT89C51SND1C Max 20 MHz clockMax 20 MHz clock 64K Flash64K Flash 2K RAM2K RAM SPI, UARTSPI, UART On-Chip MP3 DecoderOn-Chip MP3 Decoder 44 GPIO Pins44 GPIO Pins 2.7 – 3.3V Operating Voltage2.7 – 3.3V Operating Voltage TQFP 80 PackageTQFP 80 Package Cost: $15.48Cost: $15.48

Component Selection PMD microcontrollerPMD microcontroller –8-bit processor Maintain low costMaintain low cost More bits unnecessaryMore bits unnecessary –SPI port for two slaves Wireless & flash memoryWireless & flash memory –General input/output pins At least 2 inputs for user controlsAt least 2 inputs for user controls Up to 8 outputs for status LEDsUp to 8 outputs for status LEDs –Flash memory 9 KB for filesystem library9 KB for filesystem library 10 KB for application space10 KB for application space –2 KB RAM for filesystem buffering –Clock Preferably internal & programmablePreferably internal & programmable Minimum 2.5 MHz (128 x 2 kHz for SPI x 10 to be safe)Minimum 2.5 MHz (128 x 2 kHz for SPI x 10 to be safe) –Lowest available power consumption

Component Selection PMD microcontrollerPMD microcontroller –Atmel ATmega644 8 Mhz on-chip oscillator8 Mhz on-chip oscillator 64K Flash64K Flash 4K RAM4K RAM SPI, UARTSPI, UART 32 GPIO pins32 GPIO pins 1.8 – 5.5V operating voltage1.8 – 5.5V operating voltage TQFP 44 packageTQFP 44 package Cost: $7.87Cost: $7.87

Component Selection Wireless transceiverWireless transceiver –Bluetooth Class 1 or 2 Device –SPI interfacing –Low Power Consumption –Integrated Antenna –Mitsumi WRL-C40 Bluetooth 2.0 Module Class 1 Bluetooth DeviceClass 1 Bluetooth Device SPI, UART interface circuitsSPI, UART interface circuits 90 mA typical current draw90 mA typical current draw

Component Selection LCD screenLCD screen –Large enough character display size for menus and audio track information –Physical dimensions of the display –CFAH2004A-TFH-JP 4 line, 20 character display4 line, 20 character display 98mm x 60mm98mm x 60mm

Component Selection PMD BatteryPMD Battery –3.7V –Rechargeable, Lithium Ion –Largest lifetime with a reasonable size –Tenergy PL V3.7V 850 mAh850 mAh 62mm x 35mm x 3.8mm62mm x 35mm x 3.8mm

Packaging – PMD White vacuum- formed plastic enclosureWhite vacuum- formed plastic enclosure 67mm x 90mm x 15mm67mm x 90mm x 15mm 2 bi-color LED indicators2 bi-color LED indicators Power toggle switchPower toggle switch

Packaging – Base Station White vacuum- formed plastic enclosureWhite vacuum- formed plastic enclosure 140mm x 140mm x 28mm140mm x 140mm x 28mm 2 LED indicators2 LED indicators 4 user inputs4 user inputs

Schematic/Theory of Operation Base station powerBase station power –5 VDC from wall wart into barrel jack –MAX1818 LDO regulator drops to 3.3 V

Schematic/Theory of Operation Base Station LCDBase Station LCD –5 VDC unregulated power –3 control & 8 data lines from microcontroller –Potentiometer for contrast control kept internal

Schematic/Theory of Operation Base Station I/OBase Station I/O –Four directional buttons for menu navigation –Bi-color LED for Bluetooth status indication –Single-color LED for power status indication

Schematic/Theory of Operation Base Station Bluetooth ModuleBase Station Bluetooth Module –Connected to micro- controller as SPI slave –Slave select signal provided by P2.1 on microcontroller –UART signals provided for emergency

Schematic/Theory of Operation Base Station microSDBase Station microSD –Provides data memory for cached songs –Operates using (6-pin) SD Mode –Interfaces with micro- controller via SPI –Slave select signal provided by P0.7

PCB Layout Base Station Digital-to-Audio ConverterBase Station Digital-to-Audio Converter –Receives system and data clock, audio data, and channel selection from microcontroller –Accepts data in I 2 S format –Configuration registers can be modified using MS, MC, and MD signals –Outputs stereo audio signal at line level

Schematic/Theory of Operation Base Station MicrocontrollerBase Station Microcontroller –External 20 MHz oscillator –PLL filter circuit –I/O expansion header

Schematic/Theory of Operation Base Station In-Circuit ProgrammingBase Station In-Circuit Programming –“Proprietary” RS-232 connection through 8-pin header –RS-232 level translator –Communicates with microcontroller via UART

Schematic/Theory of Operation PMD Microcontroller & I/OPMD Microcontroller & I/O –Header to monitor output, SPI chip select signals, and battery status input –Expansion header for future UART & I/O use, if necessary

Schematic/Theory of Operation PMD SPIPMD SPI –Same Bluetooth & microSD connections as on base station –SPI header used for ISP

Schematic/Theory of Operation PMD PowerPMD Power –3.7 V 850 mAh Li+ battery –3.3 V supplied by MAX710 step- up/down regulator –5 V from mini USB –MAX1811 handles battery charging, provides battery status signals

PCB - BS Component PlacementComponent Placement Bypass capacitor locationBypass capacitor location Oscillator crystalOscillator crystal 120mm x 105mm120mm x 105mm

PCB - BS

PCB – BS – Power separation

PCB – BS - Bluetooth

PCB – PMD Component PlacementComponent Placement Bypass capacitor locationBypass capacitor location Headers!Headers! 85mm x 65mm - Size Constraint85mm x 65mm - Size Constraint

PCB - PMD

PCB – PMD – Power Management

PCB – PMD – SPI

Base StationBase Station –Uses PMDs as remote storage –MP3 decoder is interrupt-driven Software Design

PMDPMD –Slave to the base station –Sole purpose is providing music files

Software Design SD Flash Memory CardSD Flash Memory Card –Both units utilize SD Flash –PMD for main storage –Base station for a large cache FAT16 FilesystemFAT16 Filesystem –Chosen for compatibility –Implemented with an open source library

Project Completion Timeline

Questions / Discussion