GM Lan Single Wire CAN Bus Sniffing

[msenj]

Dusted off my Arduino and picked up a CAN shield for it. Apparently it will do SWCAN. Let the fun begin

Can't remember if I sent you the link to it, but you can see that shield being used in a G8 here.

Shows a picture of that exact shield about four posts down.

[ZerOne]

From the G8 Forum.

$30 Arduino UNO controller (sparkfun.com)
$45 Arduino CANbus board (sparkfun.com)
$12 Arduino RS232 board (Cutedigi.com)
$15 Arduino prototyping board (sparkfun.com)
$145 Escient Fireball FP-1 (ebay)
$60 DC-DC converter (probably not needed. mp3car.com)

This is fantastic news that there is a shield for Arduino that supports SW CAN.
Looks like I will need to do some shopping !!

[msenj]

From the G8 Forum.

$30 Arduino UNO controller (sparkfun.com)
$45 Arduino CANbus board (sparkfun.com)
$12 Arduino RS232 board (Cutedigi.com)
$15 Arduino prototyping board (sparkfun.com)
$145 Escient Fireball FP-1 (ebay)
$60 DC-DC converter (probably not needed. mp3car.com)

This is fantastic news that there is a shield for Arduino that supports SW CAN.
Looks like I will need to do some shopping !!

Yup. Me too. In a couple of weeks when this damn wedding and honeymoon are over and I can get back to more serious business... Like working on my car!

[msenj]

Have been talking to George who used the Arduino and CAN shield in his G8.

He says: "The one thing I had to do to the CANbus shield to get it to work with GMLAN was to tie the CANL input to ground and just use CANH as the single-ended data line."

He's sent me through his software too, but I'll have to ask him if he doesn't mind me sharing it.

[jezzab]

Compiles fine after you download the Bounce library if you dont have it. Even uploads and runs on my Arduino Uno so far. Ill hook up the shield tomorrow some time. They send me it without pins *sigh* so i will have to solder them on.

I can see with the serial monitor its trying to communicate with the Fireball media unit.

Posting it up should be a problem, its says in the notes that its GNU etc

Jez

[ghodge]

You all have no idea how glad I am that msenj contacted me. I've spent many a night googling and searching for the information contained on this site. I don't know a lot about the use of GMLAN in our vehicles but I'll offer what little information I have. I'll have to post up the software that I run on the Arduino/CANbus shield combo that sniffs the bus and sends data to my laptop for later analysis.

George

[msenj]

And here, now I have his approval, is g8MediaNav, the software ghodge sent me for the Arduino/CAN shield to use an Escient serial controlled iPod interface in the G8.

[ZerOne]

Hi there ghodge !!!

Welcome aboard !
Thankyou for sharing your software with everyone, it is HUGELY appreciated.

I have given you access to the contributers section, where there are some more goodies to look at
I am in the process of purchasing a CAN shield for my Arduino, so hopefully soon I can play as well, and hopefully contribute more than what I have so far.

I am also writing software that will analyze the GM Lan packet received, and will try and log packets that are unknown
to a file. The main reason for writing the software is I have a Single Wire CAN modified ELM327 by GTOSoft.
The module fills its serial buffer very very quickly, and requires manual intervention to continue sniffing the bus.

I am resolved to the fact that this adaptor will drop a lot of packets, so the hope is that I try things over and over again, and have the software filter out anything known, and highlight anything new...

Thats the hope anyway.

The software is written in C# (Mono) using GTK+ bindings, and I have tested what I have so far on Mac OSX (Snow Leopard), Ubuntu 10.04 (LTS) and Ubuntu 11.10, WIndows XP and WIndows 7.

So far the code runs on all these platforms, but I have issues with sending serial port data with some operating systems. (I a writing a fix for this right now)....
Hopefully when I have something that is useful, I will post up the source code to this as well.

In the mean time, I have the adapter hooked up on a bench to a Colour LCD Radio/HVAC unit, and will be connecting up an Omega cluster very shortly.
I have ordered some steering wheel buttons (Thanks DaveM for the idea), and will try and log some stuff
to test the setup soon.

I also have a SatNav gateway module, which is easily pulled from the car.
The connector looks simple enough, so I will try and mod something on the bench, to see if I can get the VGA Input working on the bench, and nut out what SW Lan commands are needed to get things happening...

Hopefully I will have something to show this weekend

Cheers, and Welcome again

[ghodge]

ZerOne,

Thanks for the warm welcome. I wish I could take credit for the code. I took code from a G8 board member, made some adds and deletes for my purposes, and GPL'd it with his permission. I'll post the scanner code ( which was done by Terry - gotta give credit where it's due) that I run on the Arduino too. I haven't implemented it yet by my CANbus shield has a SD slot on it. I just need to add code to write a SD card. I currently just stream over a serial port to my laptop.

I'm excited to hear that you were working with the SatNav gateway module. I really hope you get the VGA input working as composite that I currently have to use is pretty bad. I wonder if the SatNav gateway module would work with a G8. I'm especially hoping for you success in getting GMLAN packet filtering working. I've been trying to see if any of the disc/track/preset buttons show up on GMLAN but from what I can tell through my sniffing, they don't.

I've since gone from the Escient iPod dock to a DLO Homedock and now I want to replace everything with a beagleboard or a rasberry pi connected to the Arduino GMLAN interface and run the cmus music player. My motivation is to get rid of the iPod docks that can take anywhere from 35 seconds to a minute to boot up and don't always boot up reliably in a car environment. I can modify the software/Linux distribution running on the beagleboard (which I've already purchased) or rasberry pi to boot much faster and I'll have significantly more control over things.

Here's a few links that I've learned some things from:

gmlanhack.blogspot.com (I basically added some code to Terry's code to handle input from the navigation joystick and control the iPod dock )
canbushack.com/blog/index.php
mp3car.com/engine-management-obd-ii-engine-diagnostics-etc/141976-gmlan-sw-can-message-woes.html
mp3car.com/engine-management-obd-ii-engine-diagnostics-etc/139533-low-speed-gmlan-interface.html
g8board.com/forums/showthread.php?t=28602 (the thread that got me started down this path)
https://github.com/gtosoft/libvoyager

[msenj]

Just one thing to be aware of when calling the Nav video input on the headunit "VGA".

It's technically RGB+Composite Sync, like the old 386-era 9 pin monitors.

I did some research on this, and it will accept signals from a newer video source, but the H+V sync lines need to be tied together, and it only works with a 15kHz horizontal scan rate - Most modern video chipsets can't output this low, so either a hardware scan rate converter is needed, or if you're lucky enough to have a video chipset that supports it, you can use Soft15KHz to force a 15KHz horizontal scan rate.

This is confirmed in the spec sheet for the panel itself.

The native resolution of the panel is 480x234, so there will be a lot of screwing around to get any modern flavour of Windows working at this resolution - Most of the hardware scan converters will take an 800x600 signal and scale it, and then let you adjust it to make it fit.

Edit: Looks like I'm the only one around here that doesn't already have an Arduino... I'm a bad geek.