Newsgroups: sci.electronics.misc
Subject: Re: I2C in an automotive environment
References: 
Amos K  writes:

> I'm starting a system design for my car that will need an interface
> between each subsystem (alarm and locks, engine control, windows and
> lights, stereo, displays ect...)  I chose I2C over RS-485 because it
> is widely accepted and easy to impliment with minimal parts.  

I2C is widely accepted and eeasy to implement with minimal parts. 
The traditional I2C is not useful outside the box for anything 
that needs reliabity, because it is quite sensitive to interference 
(unbalanced bus with open collector drivers and weak pull-up) and 
the communication protocol/ICs does not have any useful built-in error 
detection/correction. 

I have heard somebody mention I2C over RS-485. 
I have not heard much of it or seen it used anywhere, so I doubt 
that it woudl be widely accepted. 

> Has anyone tried using it in an automotive environment?  

I have not tried to use it in automotive enviroment. 
I have used I2C on some other things...

> I'm concerned
> there might be to much interference causing data transmittion problems.
> 
> Is there maybe a better thread for this question someone knows about?
> 
> Thanks for any input
> 
> -Amos
> 

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/