Deep Memory Automotive Data Logger

Adolph SeemaAdolph Seema

Paul KuruczPaul Kurucz

Motivation

Paul’s ideaPaul’s idea

Presentation Plan

Description of the project.Description of the project. System BreakdownSystem Breakdown

User ProfileUser Profile Software & System Design ConstraintsSoftware & System Design Constraints

Hardware-Software InterfaceHardware-Software Interface- OBD-II setup- OBD-II setup- OSI-9141 and SAE-J1979- OSI-9141 and SAE-J1979- Logging structure.- Logging structure.

System Description Modern vehicles contain a myriad of Modern vehicles contain a myriad of

sensors.sensors. Sensors are monitored by the engine control Sensors are monitored by the engine control

unit (ECU) to determine the status of the unit (ECU) to determine the status of the vehicle’s critical systems such as engine vehicle’s critical systems such as engine speed, coolant temperature, fuel pressure speed, coolant temperature, fuel pressure and intake air density. and intake air density.

Most vehicles Most vehicles since 1996since 1996 have O have On-Board n-Board Diagnostic (OBD-II) connector.Diagnostic (OBD-II) connector. Service Engine Soon light?Service Engine Soon light?

Goal Design and implement a data logger that Design and implement a data logger that communicates with the ECU via the communicates with the ECU via the OBD-II OBD-II connector.connector.

Use the Dell AximUse the Dell AximTMTM X5 PDA as the data X5 PDA as the data logger and the user interface between the logger and the user interface between the OBD-II and the user.OBD-II and the user.

Data logged should be compressed into a Data logged should be compressed into a Compact Flash that could be read by a Linux Compact Flash that could be read by a Linux station through the flash reader. station through the flash reader.

The Compact Flash Reader and the PDA

Flash Reader and PDA Cont… The reader accepts six types of flash mediaThe reader accepts six types of flash media

Compact Flash, Smart Media, Secure Compact Flash, Smart Media, Secure Digital, Memory Stick, Micro Driver and Digital, Memory Stick, Micro Driver and MMC multimedia card. MMC multimedia card.

The Dell PDA accepts three types of flash The Dell PDA accepts three types of flash mediamedia Compact Flash, Secure Digital and Compact Flash, Secure Digital and

MMC multimedia card MMC multimedia card

Dell Axim PDA

Compact Flash Card

Level Converter

3.3 Volt Serial

Male to Male Crossover Gender changer

RS-232

ECU

OBD-II Connecto

r

RS-232 to OBD-II Converter

PIC

UART

Level Converting

Circuits

Golf TDI

System Components PDA is the primary system controller that PDA is the primary system controller that

provides the data logging and compression provides the data logging and compression services along with the user interface. services along with the user interface.

The RS232 to OBD-II interface converter The RS232 to OBD-II interface converter contains a PIC micro-controller and electrical contains a PIC micro-controller and electrical interface circuitry.interface circuitry.

The interface converter allows the PDA to The interface converter allows the PDA to communicate with vehicles that use each of communicate with vehicles that use each of the three different physical layer protocols, the three different physical layer protocols, while only using one command set and baud while only using one command set and baud rate.rate.

User Profile After everything is connected and workingAfter everything is connected and working

Three protocols possible to be implemented.

DMADAL

Please Select OBD-II Protocol:

PWM (SAE 1850) VPWM (SAE 1850) KWP2000 (ISO 9141)

Continue

DMADAL

What do you want to do?

Data Logging Diagnostic Clear Check Engine

Continue

Choosing sensors to be logged and vehicle.

DMADAL

Please Select Sensors to Log:

Mass Air Flow

Continue

Coolant Temp

Engine RPM

Engine Load

Car Speed

Fuel Pressure

Throttle Pos

In. Air Temp

Man Air Press

If we have time we will create a “database” of a few vehicles

DMADAL

Sensors being logged

Wait/Stop

Fuel Pressure 500 Psi

Man Air Press.

1.5 Bar

In. Air Temp. 97 ºF

Choosing specific log settings.

DMADAL

Specific Logging Settings

Done

MODE 8

Intervals 5 ms

PID 3968

More

Total Samples

5000

Secondary functionality

If we have time we will create a “database” of a few vehicles DTC description

DMADAL

1 Engine Codes Present:

Go Back

Code:

Description: P0001 An Engine Code

DMADAL

Specify Vehicle

Continue

Make: Volkswagen

Model:

Golf TDI

Year: 2003

Basic OBD-II Modes Nine (9) modesNine (9) modes Mode 1Mode 1

Vehicle speed, RPM, fuel system status, OVehicle speed, RPM, fuel system status, O22 sensor sensor voltages, temperatures and timing advance.voltages, temperatures and timing advance.

Mode 2Mode 2 A snapshot of mode 1 settings when a trouble code A snapshot of mode 1 settings when a trouble code

condition occurredcondition occurred Mode 3Mode 3

Retrieves powertrain trouble codes (P codes) from Retrieves powertrain trouble codes (P codes) from the ECU. The ECU may not respond if there are no the ECU. The ECU may not respond if there are no trouble codes present.trouble codes present.

Mode 4Mode 4 Clears all diagnostic and trouble code data.Clears all diagnostic and trouble code data.

Basic OBD-II Modes

Mode 5Mode 5 OO22 sensor test results on some vehicles. sensor test results on some vehicles.

Mode 6Mode 6 Non-continuously monitored test results.Non-continuously monitored test results.

Mode 7Mode 7 Continuously monitored test results. Continuously monitored test results.

Mode 8Mode 8 Requests control of on-board devices. Not well Requests control of on-board devices. Not well

defineddefined Mode 9Mode 9

Reports VIN # and calibration constants.Reports VIN # and calibration constants.

Software & System Design Constraints

Primarily Microsoft embedded Visual C++ Primarily Microsoft embedded Visual C++ (eVC++) for the GUI, C for basic libraries.(eVC++) for the GUI, C for basic libraries.

OBD-II. INTERFACE

d

ENGINE SENSORS

PDA-ARM Processor

DISPLAY STATION

LINUX BOX

PDA

LCD

Software System Diagram

Communication Core

Platform Independent Serial I/F Library

OBD-II I/F Stack

Compression Library (miniLZO)

File I/O Library

Data Packetizer

Sampling Timer

Windows CE Serial System Calls

Windows CE File System Calls

UI System Controller

GUI

Error Code DB Windows CE File System Calls

ISO 9141 – Phy Layer

ISO 9141 – Data Link

SAE J1979 – App Layer

Platform Independent Accurate Timers

Windows CE Accurate System Timers

Formatting GUI requests Two typesTwo types

Scheduler Request Format Scheduler Request Format Query format Query format

QF|________| |________|Mode PID

SRF|________| |________| |________| |________|Mode PID Intervals Sample Count

The Query Format Primarily for Secondary functionality

PDA Resources The Dell AximThe Dell AximTMTM X5 PDA has: X5 PDA has:

Built in 32 MB of FlashBuilt in 32 MB of Flash 32 MB of built-in RAM32 MB of built-in RAM

2 external flash storages including2 external flash storages including The Compact Flash, which can go up to The Compact Flash, which can go up to

3GB3GB We have 2 128MB Compact Flashes.We have 2 128MB Compact Flashes.

APPENDIX[1] OBD II Interface Chip Data Sheet For PWM, VPW, and ISO 9141-2 Vehicleshttp://www.obddiagnostics.com/DataSheet.pdf[2] ODB Notes. A collection of a few fact on OBD-II[3] INTERNATIONAL STANDARD IS0 9141 First edition 1989-10-01[4] INTERNATIONAL STANDARD IS0 9141-2 First edition 1994-02-01[5] SAE International, SURFACE VEHICLE STANDARD J1979 REV. APR2002[6] miniLZO Resource Center, http://www.oberhumer.com/opensource/lzo/#minilzo[7] Microsoft Developer Network, MSDN, http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vcsample/html/vcorivisualcsamplesportal.asp[8] Circuit Cellular, http://www.circuitcellar.com/library/print/0103/Eady150/index.htm[9] Stanford University Fact http://www.stanford.edu/class/ee281/projects/aut2001/mp3player/fat16.htm[10] eMbedded Development Ultimate Information Site, 2001, eVC++ Tutorial, Daniel Lehtovirta http://www.justppc.com/evc1.shtml

Question Time