The New Car Computer: CAN I & II

[Glacier991]

Someone came up with a software/hardware package years back called ELM. It was a geekish shareware thing and a lot of people have done a lot with it. Now that CAN is here with bus speeds approaching standard computer backbone speeds.... someone has taken ELM into that realm. While I do not have my NGS yet (but will) I plan to investigate this software... it is just too cheap (and promising) not to!

www.myscantool.com

Some of the features blow me away, like the graphing multi trace oscilloscope (I hear it can do that) and the pseudo dyno features.

 

[ExplorerDMB]

Chris - I'm going to sticky this. Anymore CAN information will be great to have in here.

-Drew

 

[ExplorerDMB]

Module Communication

We are seeing a lot more "modules" being used to control most of the electrical components in our vehicles, including their operation. A typical vehicle will have ten or more modules and they communicate with each other over wiring and data lines; but don't be surprised to see more than 20 modules in a Cadillac.

SAE Classification:

The Society of Automotive Engineers (SAE) standards include three categories of in-vehicle networks including: Class A, Class B, and Class B communication networks.


Class A

These are lower-speed netowrks (less than 10,000 bits per second). These are generaly used for trip coputers, entertainment, and other convenience features.


Class B

Medium-speed netowrks (10,000 to 125,000 bits per second) are generally used for information transfered among modules, such as instrument clusters, temp sensors, and other general uses.


Class C

These are the somewhat "future" of networks. These are high-speed networks which run from 125,000 to 1,000,000 bits per second, which are usually used for real time powertrain data and vehicle dynamic control systems. Most high-speed bus communication is controller area network (CAN).


Here is a picture of CAN:

Definitions

A Bit - A fundamental unit of information having just two possible values, as either of the binary digits 0 or 1 (in other words, on/off switching)

Bus - A bus is a term used to describe a communication network.



I hope this is some useful information for the readers out there.

-Drew

 

[Glacier991]

I loaned out my ELM based system to a frend who also is a computer whiz.... he will shortly be posting here and I will make sure it gets prominent notice, his review.... mainly of ELM but also of the EEC-V bus. Can you say SLOW ?

CAN is hugely faster. Scanners can make good use of that speed, real time.

 

[ExplorerDMB]

I agree with you Chris.

 

[foxy]

ExplorerDMB, Mate I have just bought a ELM5 Blue Tooth and I've been told by Scantool.net that it would be able to cope with CAN no problems. I believe that to increase the BAUD rate also should not be a problem with this item as it has the latest ELM chip on board as CAN is supposed to be pretty quick please correct me if I'm wrong Cheers Foxy