According to the Helms, the bus between the nav unit and the touch screen is GA-NET II. I've been googling a bunch for it, and haven't come up with anything too solid. I've taken some data captures with an osciloscope, and it isn't obvious how the protocol works. I plan on taking some more indepth data captures with a high speed data logger soon to see if it makes more sense when I have several different messages to compare.

If anyone has any info about it, I would really appreciate it.

Thanks,
Dave

 

I read your post and am sorry i do not have any info for you. However, I do see that you have a helms manual and ypu know something about electronics becuase you have used an osciloscope. So my question for you is, could u do me a huge favor and look and see if you can find me a place to pick up the VSS signal. I would think the nav system uses that as an input so that would be the place to start. So, if you could please find the time to see if you can find some place that i can get the singal from please include wire color and location.

Thank you so much.

 

There is absolutely no information regarding GA-NET II on the internet...

However, there is a lot of information regarding the wiring of the nav system in the following thread:

http://www.acura-tsx.com/forums/showthread.php?t=10375

 

Abrams,

On my '02 TL the vehicle speed sensor is connected to the BLU/WHT wire going into the nav unit in the trunk. It is in the 8 pin connector (pin 6) on the back of the unit (when looking at the rear of the unit the left most connector that is not the gps antenna. If you need more info email me at dave@morecaffeine.net. Just curious, what are you planning to do with the vehicle speed signal?

Dave

 

Thanks for the info daniel. I had come across that thread the other night. I can't beleive there is no info available on GA-NET II. I searched high and low, and finally figured I'd just post to as many acura forums as I could in hopes that someone would have some info for me.

What I am trying to do is tap off the signals from the touch screen, so I can use it as input to a computer for MP3's and various other things.

Dave

 

Yep... I've been trying to do the same...

 

Have you made any progress?

Contact me, dave@morecaffeine.net

I was planning on doing some more work tommorow with a firend of mine (we both have TL's). I have a high speed (1.25MHz) data aquisistion unit that I was going to use to record transactions on the bus and try to figure it out. At the very least, I should be able to differentiate what was pressed, even if I can't actually figure out the protocol. I'll let you know what I find out. If you are interested in the osilloscope images I took last time I worked on it, let me know, I'll send them over....

Dave

 

I suspect that it is an improved version of the Alpine Ai-NET protocol, if not the same protocol with a different name.

It is NOT any industry-standard protocol like CAN or MOST or anything like that.

 

I've found out a little bit more about GA-NET II. Someone was kind enought to point out to me that GA-NET II was really a protocol developed by NEC, IE Bus. Here is the chip that is used in the Nav Units:

http://www.necel.com/partic/function...bus/d6708.html

About 6 months ago myself and a friend of mine had hooked up a data recorder to the Data Bus on his car and recored a bunch of data. We were never able to make much sense of it untill it was pointed out that it was really IEBus. I wrote a quick program to churn through the recorded data and decode the data packets. A good portion of it seems to make sense to me now. I can tell what button or touchscreen location was pressed. Unfortunately I can't seem to get my hands on those NEC chips (they are sold by NEC automotive group in japan and I don't know where to order them from, I spoke to an NEC rep in the US but haven't had any luck so far).

I am probably going to try to design my own decoder chip in programmable logic one of these days when I have some more time.

Just wanted to share this since I haven't been able to find any information about GA-NET II on the web anywhere.

If anyone needs any more information or would like a copy of my data captures and decoder program feel free to email me at dave@morecaffeine.net

Dave

 

It would totally kick ass if I could tap into the touch screen for my CarPC (to be ordered this week)...

 

I know it's been a while, but are you still working on this?