Reverse engineer a one-wire bus

[alanr723]

I built a computer in my car, mainly for navigation and mp3 purposes. I would like to display song/artist information to the OEM LCD screen.

There is a one wire bus in a wiring harness that carries data (track name, artist name, XM channel) from the XM tuner to the LCD in the dash. I'm assuming it's binary in a 12V+ (on) and 0V (off) sort of configuration.

Here's where I need EE help. What kind of tool can I use to "listen in" to this and record the signal so that I can analyze it? I was thinking an oscilloscope or logic analyzer might be what I need, but I know nothing about either. It would be best to get this data into a computer where I could manipulate it with some code...

Once this is possible, the next huge step would be to figure out the protocol and try to write to this bus :) But I'll save that for later.

 

[berkeman]

Here's a pretty good inexpensive logic analyzer pod that we use here at my work for simpler tasks. It would be the easiest way to monitor the signal and get it into a computer for you to analyze.

http://www.tech-tools.com/dv_main.htm

Also check out Dallas Semiconducdtor's 1-wire "Touch" IO standard. It's probably different from the XM standard, but it will give you some ideas of things to look for in 1-wire comm.

 

[alanr723]

thanks for the help!