Multifunction steering wheel to control PC in a 190...

[V12]

Now you all must think i'm crazy.
But i have installed a mini ITX machine in my 190, with a 8" touch screen...all working great.

BUT

I got hold of a half birds eye maple, half black leather wheel from a facelift 210 with multifunction airbag.

Now i have chatted with some more in the know on the PC side of things and have come up with a Joystick port interface circuit that i can use to control my mediaplayer...
LINK HERE

However i have been tinkering with a multimeter on the airbag, and cannot work out what is what. Anyone got a wireing diagram for it. I'm guessing it uses some kind of digital interface, that connects either to the cluster usually or elswhere...

ANY light shed would be great...

Thanks,
Ricky

 

[guydewdney]

what about takng the wheel apart more and bypassing the electronics (if any) inside and just directly using the switches in the controls?

 

[Surf Blau]

It operates with a certain protocol which is sent to the MF instrumentcluster to be interpreted. I've seen pics of a W124 with a MF steering wheel where the owner claimed to have overcome this though. I'm guessing he re-did the switches to make them regular "on/off" switches though..

 

[V12]

That's what my conclusions were pointing to...
I'll let you know how i get on then.

Thanks.

 

[IanT]

Yep, the steering wheel switches are connected via a CAN bus. That means there's a small embedded micro in the steering weel with a transceiver and the same at the other end of each device connected to the bus.

There was a good project link on here a couple of months ago where someone built an interface and had reverse engineered the protocol so they could control other things with the steering wheel.

Vauxhall do it differently, Vectras have 6 buttons which simply change the voltage across two pins of a 3-wire interface by using a weighted resistor potential divider. Simple and seems to work fine.

It might be worth using the standard CANbus but if you're not ready for that much work, you could modify a simple remote control to fit inside the steering wheel and do it wirelessly. Connecting up all the buttons leaves you with a huge problem in that you've then got 9 cores of wire that need to coil and uncoil as you turn the wheel.

Oh, and if you change your mind, I'd love one of those wheels in my facelift W210...

Ian.

 

[V12]

Thanks for the confirmation,
I have a few half wood wheels, let me know what wood and what colour you want and i'll see what i have...

Ricky

 

[IanT]

I'm after the same as yours - my car's an Avantgarde so I'd be wanting the bird's eye maple (black) one.

Or, if not, a standard black leather one that's new would do I guess.

Cheers, Ian.