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https://github.com/endurodave/obdii-adapter-software

OBDII adapter source code and schematic for automotive diagnostic vehicle communication.
https://github.com/endurodave/obdii-adapter-software

canbus elm elm327 obd-ii obd2 obdii obdii-dongle obdii-interface obdii-library scan-tool

Last synced: about 2 months ago
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OBDII adapter source code and schematic for automotive diagnostic vehicle communication.

Host: GitHub
URL: https://github.com/endurodave/obdii-adapter-software
Owner: endurodave
License: mit
Created: 2024-11-12T14:13:01.000Z (about 2 months ago)
Default Branch: main
Last Pushed: 2024-11-12T15:25:01.000Z (about 2 months ago)
Last Synced: 2024-11-12T15:30:17.210Z (about 2 months ago)
Topics: canbus, elm, elm327, obd-ii, obd2, obdii, obdii-dongle, obdii-interface, obdii-library, scan-tool
Language: C
Homepage:
Size: 10.2 MB
Stars: 0
Watchers: 1
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

        # OBD-II Scan Tool Adapter 

C language source code and schematic for an automotive OBD-II scan tool adapter. 

# Table of Contents

- [OBD-II Scan Tool Adapter](#obd-ii-scan-tool-adapter)

- [Table of Contents](#table-of-contents)

- [Overview](#overview)

- [Auterra Scan Tools](#auterra-scan-tools)

- [OBD-II Adapter Host Protocol](#obd-ii-adapter-host-protocol)

  - [Enhanced OBD-II](#enhanced-obd-ii)

- [OBD-II Adapter Software Source Code](#obd-ii-adapter-software-source-code)

  - [SAE J1850 VPW/PWN](#sae-j1850-vpwpwn)

  - [ISO 9141 and 14320](#iso-9141-and-14320)

  - [ISO 15765](#iso-15765)

- [OBD-II Adapter Hardware Schematic](#obd-ii-adapter-hardware-schematic)

- [Why Open Source?](#why-open-source)

- [Auterra Scan Tool Products](#auterra-scan-tool-products)

  - [Dyno-Scan for Windows](#dyno-scan-for-windows)

  - [DashDyno SPD](#dashdyno-spd)

  - [Dyno-Scan for Android](#dyno-scan-for-android)

# Overview

An OBD-II (On-Board Diagnostics II) scan tool adapter serves as a bridge device between a host (e.g. PC, phone, embedded device) and the vehicle. The OBD-II adapter translates serial messages to and from OBD-II vehicle messages. Very similar in concept to an ELM327 chip except all C language source code, protocol documentation and schematic is provided. The adapter supports all known OBD-II automotive protocols starting from 1996 model year.

* SAE J1850 (VPW, PWM)

* ISO 9141-2 (ISO)

* ISO 14320-4 (KWP 2000)

* ISO 15765-4 (CAN bus)

A vehicle 16-pin OBD-II connector is typically located on the driver's size under the dashboard.

![OBD II Diagram](images/DynoScanLineArtWindows.gif)

The software source code is being open-sourced for public use under the MIT License.

# Auterra Scan Tools

The Auterra series of scan tools was sold for about 15 years starting in 2000. Different versions of the tool were sold. See the [docs](docs/) folder for user manuals.

* [DashDyno SPD](/docs/DashDynoManual.pdf) - an all-in-one handheld scan tool

* [Dyno-Scan for Windows](/docs/Dyno-ScanWindowsManual.pdf) - a Windows scan tool (serial, USB, Bluetooth)

* [Dyno-Scan for Android](/docs/Dyno-ScanAndroidManual.pdf) - a Android scan tool for phone/tablet (Bluetooth)

* [Dyno-Scan for Palm OS](/docs/Dyno-ScanPalmManual.pdf) - a Palm Pilot scan tool (serial)

A road dynamometer feature was added to measure horsepower and torque during vehicle acceleration extending the usefulness beyond diagnostics.

See [Auterra Scan Tools](http://auterraweb.com/index.html) company website for more product information. 

# OBD-II Adapter Host Protocol

The OBD-II host protocol is documented within the [OBD II Adapter Protocol](/docs/OBD%20II%20Adapter%20Protocol.pdf) document.

## Enhanced OBD-II

"Enhanced OBD-II" refers to a more advanced version of the standard OBD-II system, which provides additional diagnostic information specific to a vehicle's manufacturer. Whereas the generic OBD-II standards are readily available, the manufacturer specific protocol specifications are obtained with a subscription from [ETI](https://etools.org/). 

The OBD-II adapter source code supports generic and enhanced protocols. Auterra products supported enhanced OBD-II from many vehicle manufacturers such as GM, Ford, Toyota, Nissan, and Mazda. 

# OBD-II Adapter Software Source Code

The OBD-II adapter software is written in C and compiled using [CCS](https://www.ccsinfo.com/compilers.php) PCH C Compiler, Version 3.167. The code executes on the Microchip PIC18F248 microcontroller. The source code serves as a translator of generic (universal) and enhanced (manufacturer specific) OBD-II messages to/from a host device.

All microcontroller host communication is serial. On USB and Bluetooth, a serial translator was used to convert host serial messages into USB/Bluetooth. On Bluetooth, the Microchip RN42 chip was utilized in lieu of a host serial connector.

The adapter source code is located within the [src](/src/) directory. **Main.HEX** is the last adapter release. 

## SAE J1850 VPW/PWN

VPW and PWM are legacy protocols used by Ford (PWM) and GM (VPW). These interfaces were painstakingly bit-banged using assembly language and a logic analyzer. Excellent comments document the source code. Software simulation tools assisted with development.

## ISO 9141 and 14320

The ISO and KWP protocols are serial interfaces. A software-based UART available as part of the CCS compiler turns any unused port into a serial interface.

## ISO 15765

CAN bus is the latest OBD-II interface with all known speeds and modes supported by the source code. The Microchip processor has an on-board CAN bus interface.  

# OBD-II Adapter Hardware Schematic

The OBD-II adapter schematic is shown below. Actually its from the DashDyno, so the MODULAR 10 connector is a DB9 on the adapter variants. Both cable diagrams shown below. 

![OBD II Adapter Schematic](images/OBD%20II%20Adapter%20Schematic.jpg)

![OBD II Cable](images/OBDII%20Cable%20Modular.jpg)

![OBD II Cable](images/OBDII%20Cable%20DB9.jpg)

# Why Open Source? 

Auterra products are no longer commercially available. However, the released source code and documentation may serve as valuable resources for future automotive-related projects.

# Auterra Scan Tool Products

Auterra products were designed for Palm OS, Windows, Android and DashDyno platforms. All products utilized the Microchip OBD-II adapter interface processor. Software languages utilized across the various platforms was C, C++, C#, Java and assembly. 

## Dyno-Scan for Windows







## DashDyno SPD









## Dyno-Scan for Android