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© 2003 NVision Technologies
NVision Technologies presents…
NVision Technologies:Jozsef Dudas, Seema Jaffer, Deanna Lee, and Byron Thom
ENSC 340 Presentation: December 18, 2003
an Automotive Diagnostic Tool
© 2003 NVision Technologies
Overview
Meet the TeamMeet the Tool
Yesterday Today Tomorrow
Wrap-up
© 2003 NVision Technologies
Meet the Team
NVision Technologies Group Leader and Hardware Lead
Jozsef Dudas
Firmware Co-Leads Seema Jaffer, Deanna Lee
Software Lead Byron Thom
© 2003 NVision Technologies
Meet the Tool: Overview
Its purpose and marketIts marketabilityIts technical aspectsIts management
© 2003 NVision Technologies
Meet the Tool
Problem GM hobbyists needed a tuning tool
Tool interfaces with car’s computer
Current Solutions Commercial Scan tools ($300 USD) Manufacturer Tools ($10,000 USD)
Our Solution Low-cost per function…
© 2003 NVision Technologies
Meet our Tool
Low-cost Software-defined and upgradeable Full SAE compliance in a single box
Upgradeable features Accommodates user-defined add-on functions Easy incorporation of future standards
Programming the automobile computer
© 2003 NVision Technologies
The Tool: Marketability
Market Potential Growing “Import-tuner” market
Car hobbyists Accessorizers
GM knows it’s importantProduction Cost
Software is inexpensiveSuggested Retail Price
Current cheapest tool: $200 Flexible
© 2003 NVision Technologies
System Overview
© 2003 NVision Technologies
The Tool: Operation’s Concept
User: requests specific sensor data iPaq: passes data request to car via cable Cable: repackages request and sends it to the car Cable: receives data and repackages it for iPaq iPaq: receives data and displays it for the user
© 2003 NVision Technologies
The Tool: Technical Aspects
Composed of: Hardware
Platform for firmware and software
Firmware the Translator Cable control between the car
computer and the iPaq
Software the iPaq graphical user interface and control
© 2003 NVision Technologies
The Tool: Hardware
Parts ProcurementCable Hardware
OBD-II Connector, uC, Transceivers, Boards, Connectors, etc.
Board for robustness Transceiver chip for simplicity
Ipaq Versatile, fast, cheap, and sexy!
Test PCM
© 2003 NVision Technologies
The Tool: Hardware Challenges
Programming the PIC Homebrew programmer blew up Microchip ICD didn’t work Required board rework
Most things actually worked!
© 2003 NVision Technologies
The Tool: Firmware
Bridge between iPaq and PCMTransparent (standalone)Real-time Interrupt-driven hierarchyWritten in C (instead of assembly)
Portability Easy to read
© 2003 NVision Technologies
The Tool: Firmware Challenges
Simulation and Debugging Challenging to obtain debugging information Initially unfamiliar with PIC
Timing (real-time system) Problem
not enough time Solution:
Nested-interrupts Optimized code
© 2003 NVision Technologies
The Tool: Firmware Status
What works Simulation (logic) of firmware
What doesn’t Timing issues prevail I/O (firmware running on hardware)
© 2003 NVision Technologies
The Tool: Software App Layer
iPaq 3165 PDA Pocket PC 2002
J2190/J2178 SAE StandardsSerial Communications (RS-232)Graphical User Interface
© 2003 NVision Technologies
The Tool: Software App Layer
Small Screen Displays Gauge and Digital Displays
Scalability Power of J2190 Sensors and PIDs
Speed
KPH
© 2003 NVision Technologies
The Tool: Budget
Budget Predicted Total: $ 492.00 Actual Total: $1006.07 Difference: $ 514.07
Summary:
WE HAVE OVERSPENT!
© 2003 NVision Technologies
The Tool: Budget
But not really…
Total Cost: $1006.07 NSERC: $ 250.00 ESSEF: $ 200.00 Wighton (SAE Docs): $ 572.65 Net Amount: -$ 16.58
We are making a profit of $17!
© 2003 NVision Technologies
The Tool: Schedule
Hardware:
Firmware:
Software:
System Integration:
Predicted Completion Dates
October 10
October 27
November 12
December 4
Actual Completion Dates
October 15
December 4
December 1
December 17
© 2003 NVision Technologies
The Tool: Tomorrow
A lot of room for future developmentHardware
Integrate various other standards Miniaturize
Firmware Fully robust Run on a faster (available) chip Support all four communication methods
© 2003 NVision Technologies
The Tool: Tomorrow
Software Other Operating Systems
Palm, Cell Phones
Diagnostic Purposes Engine Light, Maintenance Required
Parameter Modifications Timing and Efficiency
© 2003 NVision Technologies
Team Summary
Lessons LearnedConclusionsAcknowledgements
© 2003 NVision Technologies
Lessons Learned
Mike Sjoerdsma was rightHaving the standards at the beginning is
important“Doing it right” doesn’t always get the job
done!Sometimes numerous revisions are
needed to meet requirements
© 2003 NVision Technologies
Lessons Learned
Murphy was right.Lots of problems won’t flow to the surface
until you start implementing.. And integrating
“Timing” is a big dealWin CE != Win 2KSAE standards were written by engineers
© 2003 NVision Technologies
Conclusions
It’s a good ideaIt’s a good productWe almost got it workingThis product could make money
© 2003 NVision Technologies
Acknowledgements
Andrew, Steve, the TA’s, and FredJoe’s Mom Our Teammates
© 2003 NVision Technologies
Any Questions?
© 2003 NVision Technologies
Demonstration
© 2003 NVision Technologies
Hardware
iPaq Small Portable
board Reliable Miniaturized for final version
© 2003 NVision Technologies
iPaq Software
GUI (demonstrate Dial Digital display Editing sensor data request
J2190 SAE Standard Flexibility Convoluted SAE compliance provides future scalability
Serial Multi-threading to meet real-time requirements
© 2003 NVision Technologies
Firmware: High Level
Serial (to/from iPaq)J1850 (to/from PCM)
PIC (Firmware)
PhysicalReception &
MemoryAllocation
PhysicalTransmission
Decode last bitand shift into
register
Encode next bitand shift into
register
DecodeAddress,
check CRC
Generate CRC
J1850(PCM)
PhysicalTransmission
PhysicalReception &
MemoryAllocation
iPaq
Serial (RS232 to iPaq) J1850 (to PCM)
© 2003 NVision Technologies
Firmware: Low Level
PIC Firmware
J1850 Module (communicates with PCM)
Transmission/Arbitration
J1850TxBit
RS 232 Module (communicates withiPaq)
UART
Reception
FSMShift
RegisterTiming
Main Program
J1850(PCM)
RS232(iPaq) J1850Tx
CRC BufferArbitration
J1850RxBit
FSMShift
RegisterTiming
J1850Rx
EncodeAddress
CRC Buffer
DecodeCommand
Decoder/Interpreter
Buffer(Write)
Buffer(Read)
Legend
Subroutine called in main ProgramInterrupt subroutine (I/O)Block of code (i.e. CRC)Architectural Block (i.e. Tx)Sub-Module within PIC firmwareSub-system (i.e. PIC, iPaq, etc.)
© 2003 NVision Technologies
Firmware: Simulation
Simulation (on manufacturer software) Useful to test logic Can mimic I/O to some extent
What works (everything) Transmission and reception memory management CRC generation/checking
© 2003 NVision Technologies
Firmware: H/W Debugging
PIC (Firmware)iPaq (Software)
Receive(from PCM)
GUI
Transmit(to iPaq)
Transmit(to PCM)
Receive(from iPaq)
Loopback
© 2003 NVision Technologies
Firmware: H/W Debugging
Hardware debugging Loop-back mode
What works Transmits (to PCM in loop-back) correctly Receive-interrupt issues Timing issues
Not enough time to receive (the transmission)
© 2003 NVision Technologies
Any Questions?