Into the rabbit hole ... in car PC

[decromin]

Hey all,

I know I'm late to the game for mucking about with VE series 1 AV stuffs, but it's something I've wanted to do for quite a while now. Now the car I have has some interesting ways of getting stuff on the screen, it's about time to start. Any inputs,advice or warnings would be most appreciated! The car is a 07 Calais V International, so it has the rear seat dvd as well as factory Nav fitted. I'd very much like to retail all the current functionality where possible, of course!

Here's my list of planned things to do for the moment:

Source: RPi or Android miniPC running XBMC or similar
Connection: Looking at getting in via the Rear Aux port of the DVD player (see below)
Control: CANBUS shield on arduino Leonardo to simulate keyboard presses from steering wheel controls.

plus, get a VIM mod done so it will be visible while driving.

Here's my first test with the Pi:




The video worked quite nicely, but there was a lot of noise on the audio lines. I'm not sure if it is to do with the power, or with the TRRS cable I found for the test. I'm going to try running the Pi off a battery pack next and see if that helps - if the cable is crap that's not too bad, as the plan is to make a custom one to fit as nicely as possible. If I can't isolate the noise, and the aux jack is no longer a possibility, I'll look at splicing in a video switcher near the head unit, but I would very much like to have the option of both screens seeing the content from the PC, but we will see.



Here's the leonardo with it's transmogrifier (that's what they call it) to match the old arduino pin pattern.

Dry fit seems to work OK:



I'm planning on mapping the left scroll wheel signals to up, down and enter via the leonardo, but it does mean that I'm limited in what I can do with just three controls (a back button being the one I really need to make things easy). I'm thinking of making an XBMC skin that has on screen back controls, but there are things I need to overcome with that method as well. My first step though is to get the basics working though before I get too carried away.

A question for those in the know: while I'm happy to get stuck into coding with the OBD cable, once I want to mount this permanently in the car, can I do it via a tap of some sort into the GMLAN cables?

Anyway, that's where I'm at so far! I'll try and update this as I go with more details. I'm getting a 3d printer soon, so making some nice brackets to mount all this will be one of it's first jobs, I suspect.

[doubledip]

Welcome !!!! - sounds really cool - make sure you post back with your progress.. especially the 3d printer stuff... I want one

[bryce007]

Hi Mate,

Your setup is actually quite similar to mine!
I have a CarPC already setup in my Calais V International.
I cut off the rear dvd player input out of the front head unit, and ran a RCA cable to the boot.
I have VIM flashed the stock radio.
In my boot I have a laptop running in a dock which provides RCA outputs to the stock radio.

Similar to you, I also have an arduino with the sparkfun canbus shield. I have hooked this into the SW GMLAN line, and it listens for the headunit turn on and turn off commands, as well as specific keypresses. The arduino also controlls a 4ch relay board for my laptop, amps etc, to turn them on and off. Works more reliably than splicing into the ACC line under the stock radio, since it keeps the units on even once the ignition is off (Ie pressing the power button on the radio will start everything up, as it is stock).

I also have keypresses being passed through to the laptop via USB serial from the arduino. I am using software called AAC keys on the laptop to convert the serial output of the arduino to be keypresses on the laptop.

The whole setup works like stock - I have the laptop go into standby when the car is off (running off its internal battery) it turns on the same time the headunit turns on, it is up and playing music before the screen of the stock deck is on. This has been a very stable setup for me.

With the noise issues, ground everything best you can. I put a fat 8gauge cable from the chassis of the laptop dock to remove noise.

If you want any more infos or arduino files let me know!

[decromin]

hey bryce - that setup sounds great! I've been playing with arduino controlled relays for another project, but now you've got me thinking about it here. I was looking at building a little UPS setup for the Pi to help with the power issue, but I've a couple of laptops knocking about that might just get a look in now!

The arduino code would be great - I've been playing with one that did some basic read/write work, but I've not got around to actually modifying it for the Leonardo (been testing with a Uno) - I'm hoping to use the leonardo longer term as I can then switch in a Pi, Android stick or anything else that will work with the HID implementation on the Leonardo, but I think I need to get *something* working first before I get too carried away!

What media player are you using on the laptop? How did you decide to setup the controls?

Thanks again!