OBD II Information
09-19-2004, 11:57 PM
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OBD II Information OK guys I need some help. I'm planing my senior Electrical Engineering project here at school. One of the professors wanted to write software to be able to diagnose codes from a OBD II system and interface it with a PDA. So basicaly I need all the information you guys could throw at me .....web sites, books whatever... on OBD II computers and software. Any information at all would help. Thanx
09-20-2004, 06:17 PM
#4
Try this place:
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
http://carprogrammer.com/Z28/PCM/
Good luck on your project.
Bill
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
http://carprogrammer.com/Z28/PCM/
Good luck on your project.
Bill
09-20-2004, 11:18 PM
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Depending on how deep you want to get into this project meaning do you want to build your own interface board as well as the software or do you want to purchase an off the shelf interface and write your own custom code to do the serial communications and pid decoding.
If you want the main OBDII specifications for all the different types of buses you can use the SAE site as they hold the main repository of information for OBDII. The problem with their site is the papers/books/training are pretty expensive depending on your budget and what you are looking to achieve.
http://www.sae.org
(Just do a search on OBDII Protocols, Interfaces, etc...)
If you want to purchase an off the shelf interface that you could develop your own code there are many options that are pretty inexpensive.
Most are based on the ELM chipset but you could also use Autotap's (Custom Interfaces which are located @ http://www.vehicleinterface.com/products.asp)
They provide a PDF doc that explains how to request data and their chip does all the buffering, etc...
The ELM Chipset interfaces which are more generic and most likely a bit slower depending on what you are trying to achieve are located below.
These are various manufacturers that use the ELM chip and some provide source code to their apps so you could get started easier.
http://www.obd-2.com (This company makes the boards and provides source code for you to get started with)
http://www.scantool.net/resources.htm (Just the hardware with no source)
http://www.elmelectronics.com (Which makes the chip you can buy and make the PCB yourself)
Motorola also makes chips to convert K-line ISO9141 into RS232 or J1850 (VPW) into RS232. They have chips for all three OBDII interfaces.
If you want the main OBDII specifications for all the different types of buses you can use the SAE site as they hold the main repository of information for OBDII. The problem with their site is the papers/books/training are pretty expensive depending on your budget and what you are looking to achieve.
http://www.sae.org
(Just do a search on OBDII Protocols, Interfaces, etc...)
If you want to purchase an off the shelf interface that you could develop your own code there are many options that are pretty inexpensive.
Most are based on the ELM chipset but you could also use Autotap's (Custom Interfaces which are located @ http://www.vehicleinterface.com/products.asp)
They provide a PDF doc that explains how to request data and their chip does all the buffering, etc...
The ELM Chipset interfaces which are more generic and most likely a bit slower depending on what you are trying to achieve are located below.
These are various manufacturers that use the ELM chip and some provide source code to their apps so you could get started easier.
http://www.obd-2.com (This company makes the boards and provides source code for you to get started with)
http://www.scantool.net/resources.htm (Just the hardware with no source)
http://www.elmelectronics.com (Which makes the chip you can buy and make the PCB yourself)
Motorola also makes chips to convert K-line ISO9141 into RS232 or J1850 (VPW) into RS232. They have chips for all three OBDII interfaces.
09-21-2004, 12:22 AM
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I think using the elm unit is a very good idea. It's very simple to use and has some good documentation that can help you get started.
This page has some good information as well that you will most likely need if you want to get advanced about your OBD II information polling.
http://www.hptuners.com/vpw.htm
This page has some good information as well that you will most likely need if you want to get advanced about your OBD II information polling.
http://www.hptuners.com/vpw.htm
09-21-2004, 08:25 AM
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Thanks guys I appreciate all the help. Some of these sites have a lot of good information and seem like they should get me started off on the right foot. I still don’t know how far in depth I am going to have to go with this project, I still have to iron out all the details with the professor. But thanks again everyone for the info.
