J1850 VPW Interface
AVR J1850 VPW interface to connect a Chrysler or GM car bus to a PC for On Board Diagnostic (OBD) monitoring. My interface is build around Atmel AVR mega8 controller, my favourite “workhorse”. The controller is available also in DIP package for all who not want to built with SMD components. With 8k flash memory we have plenty of space for all kind of features. The basic source code which supports all functions uses 3k code space.
See the documentation for all features and how to use it.
It seems someone has made a commercial product from my project: EMU322 Interface
Some features:
- SAE J1850 VPW to RS232 interface
- simple AT command control
- different Baud rates, from 9600 to 115200 Baud
- 4 different bus monitor functions
- support for 1 and 3 byte header messages
This interface was tested with firmware v1.06 and the following OBD software
- Scantool.net
- wOBD
- Scanmaster
- Digimoto
- Proscan
- OBDspy
- OBDII
Logger - Scantool
Mode 22
Use the firmware with 9600Baud and ELM322 tag for all mentioned tools.
Example circuit:
