ECE 477 Design Review Team 14  Spring 2006 Jason, Nathanael, David, David

Project Overview Driver interface for Solar Racing TeamDriver interface for Solar Racing Team Communication with onboard power trackers and telemetry board via CAN busCommunication with onboard power trackers and telemetry board via CAN bus Display speed, battery power, and other information on the LCDDisplay speed, battery power, and other information on the LCD Allow driver to navigate through a text-based interface to customize display information and issue commands to the power trackersAllow driver to navigate through a text-based interface to customize display information and issue commands to the power trackers

Project-Specific Success Criteria An ability to display vehicle status information on an LCD.An ability to display vehicle status information on an LCD. An ability to navigate display menus and make selections using an RPG.An ability to navigate display menus and make selections using an RPG. An ability to perform LCD backlight power management (e.g., turn the backlight on for X seconds after the RPG is turned/pressed).An ability to perform LCD backlight power management (e.g., turn the backlight on for X seconds after the RPG is turned/pressed). An ability to obtain vehicle diagnostic information via the CAN bus.An ability to obtain vehicle diagnostic information via the CAN bus. An ability to switch to “debug” mode (when a RS-232 cable is connected) in which a diagnostic menu is displayed.An ability to switch to “debug” mode (when a RS-232 cable is connected) in which a diagnostic menu is displayed.

Block Diagram

Professional Components Constraint analysis and component selection rationaleConstraint analysis and component selection rationale Patent liability analysisPatent liability analysis Reliability and safety analysisReliability and safety analysis Ethical and environmental impact analysisEthical and environmental impact analysis

Constraint Analysis

Component Selection Rationale Design constraintsDesign constraints –Microcontroller PIC18 familyPIC18 family Support CAN standardSupport CAN standard Large Flash & SRAM (CANopen library)Large Flash & SRAM (CANopen library) 29 I/O Pins29 I/O Pins –Power supply Step down from 12 VDC to 5 VDCStep down from 12 VDC to 5 VDC 12 VDC input current 12 VDC input current limit High efficiency to reduce power-lossHigh efficiency to reduce power-loss

Component Selection Rationale MicrocontrollerMicrocontroller (PIC18F series with CAN, I2C, UART, PWM) –PIC18F4680 (44pin TQFP) Cost: $6.08 *** 64Kb Flash64Kb Flash 36 I/O36 I/O –PIC18F2680 (28pin SOIC) Cost: $ I/O (not quite enough need 29)25 I/O (not quite enough need 29) Could use larger/different PLD to expand I/O, but PLD cost increase is greater than $0.54Could use larger/different PLD to expand I/O, but PLD cost increase is greater than $0.54

Component Selection Rationale Power Supply 5VDC)Power Supply 5VDC) –MAX744A 750mA output at 5VDC750mA output at 5VDC 6 external components6 external components ~88% efficient, 5VDC~88% efficient, 5VDC Needs special layout with copper poursNeeds special layout with copper pours –LTC *** 640mA output at 5VDC640mA output at 5VDC 6 external components6 external components ~90% efficient, 5VDC~90% efficient, 5VDC Recommended in class documentationRecommended in class documentation

Patent Liability Analysis OverviewOverview –Three Patent were found to be similar –Literal infringement –Infringement under doctrine of equivalent –Action Recommended

Search Result #1 Information display system for a vehicleInformation display system for a vehicle Patent Number : 5,006,829Patent Number : 5,006,829 Assignee: Honda. Giken Kogyo K.K.Assignee: Honda. Giken Kogyo K.K. Year: 1988Year: 1988 Description:Description: »Sensors »A pair of buttons are used for sequentially shifting the menu item »After a certain time interval, go to idle mode

Search Result #2 Display apparatus for vehicleDisplay apparatus for vehicle Patent Number : 5,121,112Patent Number : 5,121,112 Assignee: Nissan Motor CompanyAssignee: Nissan Motor Company Year: 1989Year: 1989 Description:Description: »Sensors »Message is assigned a degree of priority level »Indicator for alert message

Search Result #3 Information display appatatus for vehicleInformation display appatatus for vehicle Patent Number : 5,764,139Patent Number : 5,764,139 Assignee: Toyota Jidosha Kabushiki KaishaAssignee: Toyota Jidosha Kabushiki Kaisha Year: 1996Year: 1996 Description:Description: »Sensors, detecting running condition »Status are stored in local memory »Size of Speed increase when vehicle is going straight

Literal infringement Violating ConditionViolating Condition Ever claim must matchEver claim must match Potential infringement PatentPotential infringement Patent –Information display system for a vehicle

Infringement under doctrine of equivalent Not as trivial to be identifiedNot as trivial to be identified To determine what function is substantially the sameTo determine what function is substantially the same To locate the differencesTo locate the differences

Action Recommended

Reliability/Safety Analysis

Ethical/Environmental Analysis

Ethical AnalysisEthical Analysis –Focus on the safety of the driver from Hardware, Software, and System Perspectives. HardwareHardware –High Efficiency DC/DC converter was chosen for its high efficiency and short circuit protection. –Optical Isolators was installed to protect the microcontroller and LCD from Damage. –PCB was carefully designed to avoid overheating and short circuit problems.

Ethical/Environmental Analysis SoftwareSoftware –Setting the CAN communication interrupts at the highest priority to display the most accurate and timely information. SystemSystem –Surface mount components were used on PCB –Connectors have board-retention devices. –LCD and PCB were tightly mounted in a plastic enclosure.

Ethical/Environmental Analysis Environmental AnalysisEnvironmental Analysis –Product Manufacture Plastic enclosures made of non- biodegradable plasticPlastic enclosures made of non- biodegradable plastic Numbers of hazardous by-products are produced during the PCB manufacturing cycle.Numbers of hazardous by-products are produced during the PCB manufacturing cycle. –Normal Use Car runs on solar energy, no significant impact.Car runs on solar energy, no significant impact. –Disposal/Recycling

Ethical/Environmental Analysis Environmental AnalysisEnvironmental Analysis –Disposal/Recycling The plastic enclosure, which is not biodegradable, should be recycled.The plastic enclosure, which is not biodegradable, should be recycled. PCB, which contains hazardous chemicals and metals, should be disposed of properly.PCB, which contains hazardous chemicals and metals, should be disposed of properly. Encourage to recycle the entire system as a whole.Encourage to recycle the entire system as a whole.

Design Components Packaging design considerationsPackaging design considerations Schematic design considerationsSchematic design considerations PCB layout design considerationsPCB layout design considerations Software design considerationsSoftware design considerations

Packaging Design

Schematic Design Power Supply Design (page 3)Power Supply Design (page 3)

Schematic Design Microcontroller Block (page 2)Microcontroller Block (page 2)

Schematic Design PLD/LCD Block (SPI and I2C) (Page 2)PLD/LCD Block (SPI and I2C) (Page 2)

Schematic Design CAN Communications (page 3)CAN Communications (page 3)

Schematic Design RS232 Communications (page 3)RS232 Communications (page 3)

Schematic Design Button Interface (page 1)Button Interface (page 1)

Schematic Design Optoisolators (page 1)Optoisolators (page 1)

Schematic Design LEDs (page 1)LEDs (page 1)

Schematic Design Analog and Buzzer (page 1)Analog and Buzzer (page 1)

PCB layout design Consideration Trace SizeTrace Size –POWER / GND: 40 mils traces –Signal: 12 mils traces –Minimum space between two traces = 8 mils Component PlacementComponent Placement –Analog components must be separated from Digital components to avoid digital noise coupling –Active components are placed on Top layer and Passive are placed on Bottom layer. –Right Angle connectors are hanging over the boundary for easier accessibility.

PCB layout design Consideration Component PlacementComponent Placement –Mounting holes located at inches from the center of the board. –Components within each functional block should be closed to each other to minimize trace length. –The boarder of some footprints should use insertion outline to avoid placement errors.

Final PCB layout inch

Initial PCB Component PlacementComponent Placement –Mounting holes located at inches from the center of the board. –Components within each functional block should be closed to each other to minimize trace length. –The boarder of some footprints should use insertion outline to avoid placement errors.

Final PCB Please include final PCB picture here if available.

Software Design

Success Criteria Demonstrations 1.An ability to display vehicle status information on an LCD. 2.An ability to navigate display menus and make selections using an RPG. 3.An ability to perform LCD backlight power management 4.An ability to obtain vehicle diagnostic information via the CAN bus. 5.An ability to switch to “debug” mode (when a RS- 232 cable is connected) in which a diagnostic menu is displayed. PSSC Demo Video PSSC Demo Video

Individual Contributions Team Leader – (Jason)Yuk Hang ChanTeam Leader – (Jason)Yuk Hang Chan Team Member 2 – Nathanael HuffmanTeam Member 2 – Nathanael Huffman Team Member 3 – (David) Wei ZhouTeam Member 3 – (David) Wei Zhou Team Member 4 – David SungTeam Member 4 – David Sung

Team Leader – Yuk Hang Chan System menu designSystem menu design –Menu tree –Navigated by RGP buttons Debug menu designDebug menu design –Serial cable detect –Menu control Idle page display (Speed, Bar graph)Idle page display (Speed, Bar graph) Configuration of RPG buttonsConfiguration of RPG buttons

Member 2 – Nathanael Huffman Hardware DesignHardware Design SchematicSchematic PCBPCB Hardware AssemblyHardware Assembly Hardware DebuggingHardware Debugging PackagingPackaging Cable HarnessesCable Harnesses

Member 3 – David Wei Zhou Initialization Of All PeripheralsInitialization Of All Peripherals TimerTimer InterruptInterrupt A/D channel (sensors)A/D channel (sensors) CAN bus communicationCAN bus communication –Sending CAN message (polling base) –Receiving CAN message (Interrupt base) Debug Menu Data displayDebug Menu Data display

Completion of PCB design and layoutCompletion of PCB design and layout Completion of Senior Design Report and User ManualCompletion of Senior Design Report and User Manual Checking the Ethical/Environmental designs of our projectChecking the Ethical/Environmental designs of our project Involved in initial component selection and finding datasheet for each componentInvolved in initial component selection and finding datasheet for each component Member 3 – Yuan-Jiun Sung

Project Summary Important lessons learnedImportant lessons learned –Contribution to Purdue Solar team –Inter-team Cooperate with two other teamsCooperate with two other teams –Developed CAN protocol –Developed interface specifications –Intra-team Hardware vs. Software (communication)Hardware vs. Software (communication) Keep motivatedKeep motivated Start software early!Start software early! Should prepare timeline in early design stageShould prepare timeline in early design stage

Project Summary Version 2 changesVersion 2 changes Enhance menu system expandabilityEnhance menu system expandability CAN cable detectionCAN cable detection –Device won’t function without CAN cable connected Dedicated CAN buffer to ensure ability to handle busy trafficDedicated CAN buffer to ensure ability to handle busy traffic Bigger PLDBigger PLD Solar Team will continue on the projectSolar Team will continue on the project

Questions / Discussion