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ECE 477 Design Review Team 01 Fall 2010. Eric Zarowny. Jigar Gandhi. John-Taylor Smith. Chandler Wall. Outline. Project overview Project-specific success criteria Block diagram Component selection rationale Packaging design Schematic and theory of operation PCB layout
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ECE 477 Design Review Team 01 Fall 2010 Eric Zarowny Jigar Gandhi John-Taylor Smith Chandler Wall
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 • Our project is an unmanned, autonomous flying aircraft. • The aircraft will be able to transmit image, telemetry, and battery data to a ground station. • The ground station will overlay the telemetry and battery data onto the image data to create a “digital cockpit”.
Project-Specific Success Criteria • An ability to overlay telemetry and battery data onto image data in real-time using the ground station. • An ability to transmit real-time telemetry, image and battery data from the aircraft to the ground station using wireless modules. • An ability to store encoded image data on a flash memory module interfaced with the micro controller for later viewing. • An ability to upload GPS coordinates from the ground station to the aircraft. • An ability to monitor battery status and enter into a power save mode that halts image capture and transmission in order to preserve remaining battery life for flight operation.
Component Selection Rationale • PIC32MX795F512H • 64 pins • 80 MHz max frequency • 512K flash, 128K SRAM • Internal 8 MHz and 32 kHz oscillators • UART, I2C, SPI, PWM • functionality to handle all of the peripherals • Battery management system (DS2788) • Handles up to 10 cells in series • Simplicity in external circuit design
Component Selection Rationale • XBee PRO • provides 2.4 GHz wireless transmission channel • capable of transferring camera and GPS data • 1 mile range • speeds up to 250 kb/s • CMOS JPEG Camera • performs JPEG compression on the chip • will provide 15 fps • SD Card • High speed data rates • Portable, simplistic implementation
Packaging Design • Dimensions of the Airbus • Wingspan: 4’10” • Fuselage: 3’L x 5.5”W x 5”H • Dimensions of the Internal Hull • 1’8”L x 3.5”W x 3”H • Materials • Rigid foam design • Mounting PCB and battery in plane • Will have to balance weight distribution
Schematic/Theory of Operation • Lithium polymer battery • 11.1 volts • 2200 mAh • 1 switch mode DC-DC voltage regulators • 2 LDO voltage regulators • CMOS camera • 1.6V & 2.8V • I2C interface • JPEG compression • 15 fps • Micro is master and camera is slave • External clock and 20 MHz frequency provided by micro
Schematic/Theory of Operation • XBee Pro • Wireless communication with ground station • Connected to micro with CMOS UART • Baud rates set to transfer data at 250 kb/s • Autopilot • Send telemetry data to micro • Receive GPS coordinates from micro
Schematic/Theory of Operation • SD Card • store video data • SD bus mode allows for 12 Mb/s transfer • Coulomb counter • ability to monitor three lithium polymer cells in series • bidirectional open-drain serial port provides communication to micro • Electrical isolation circuit to protect micro
Software Design/Development Status • Autopilot • Tested and verified communication protocols. • We have to make customizations to ArduPilot Mega for our airframe and components. Need to finalize and test PWM input on channel 5.
Software Design/Development Status • SD Card • Standard SD communication • IIC and parallel data bus - Camera • Start condition • End condition • pre-stored in FIFO before being sent out
Software Design/Development Status • IIC Battery Management • 1 wire bus system • Micro controller is the master • Four protocols • initialization sequence (reset pulse followed by presence pulse) • write-0 • write-1 • read data
Software Design/Development Status • Micro controller • PWM • Micro controller PWM used to simulate 5th RC channel input to plane • Micro generates different frequencies to switch flight modes • UART • Handle communication between the XBee and the micro controller • Micro controller will capture telemetry data from the autopilot • Pass data to the autopilot using ArduPilot Mega’s packet system