OK. I have an 02 RR with the MID stereo unit (non LCD screen)

I cant simply throw a nav unit in cause the radio setup wont work, the loom is not in, the amp is wrong ,blah blah blah .

but could i :

- relocate the mid / CD - so that they still work
- fit a nav unit screen in and swap the diplay to a touch PC screen setup ( like matt stevenston )
- run a car PC setup through the screen

but ...

would the buttons on the nav screen automatically work with the ibus ? i.e. volume etc ?

or

could the ibus commands that the nav unit sends( which my car wouldn't understand ) be intercepted or listened to by the carPC ( which would be hooked into ibus anyhow ) and then re-sent out by the PC as commands that the rest of the car would understand?

i.e.

NAV unit volume UP > car PC > my car volume UP


any thoughts V8 or else ...

Hi Fisha

fitting a nav screen to a mid system has never been possible as the wiring loom for the nav system is completely different, on a mid system depending on the sound system that is in your car normally the amp that powered the speakers is built into the mid head unit, so if you remove your mid head unit you will loose your ability to power your speakers. However if you have the DSP sound system with the separate BM54 radio module (i.e. not built into the mid) your idea may be possible.

The way the ibus network works is each device on the network has a unique ID so for example when you turn the volume up on your MID the ibus message that is sent will look some thing like this:

C0 04 68 32 11 BF

C0 = Source Device - MID
04 = Message Length
68 = Destination Device - Radio
32 = Message Data
11 = Message Data
BF = Checksum

So if you replace you MID unit in theory if you have the separate audio system components like the sat nav system has as standard then your project will work as when you press one of the board buttons on the nav screen the ibus message that is sent out on the network will still be the correct message that the reset of the system can understand and respond too. (all be it the source device ID will be slightly different to represent the nav screen sending the message rather than the mid - MID is C0 where as the BM is F0)

I think you may have more problems with actually connecting the nav screen to the mid wiring on the rear of the screen as they are more than likely not going to be plug and play, your final and possibly the biggest problem will be finding a good quality 6.5" VGA TFT monitor to connect your carpc too. This is the primary reason why in my carpc project i decided to replace my entire nav screen with the later design as the later design uses a 7" TFT which are easily available where as 6.5" screens are very rare.

Where you said could the carpc 'translate' ibus messages e.g. carpc receives the command to switch to telephone mode the carpc could then send the command to change radio modes to the radio ecu for example if could also change the pc volume etc.. so yes it is possible to use software plugins to do this. To connect your carpc into the ibus network you need to get your self a resler interface (google it) this will allow you to connect the pc to send and receive ibus messages from pc software e.g. ibus analyser etc...

Good luck with your project! i have been working on my project for about 6 months and im still no where near finishing yet. If you need any more help or advice let me know.

Matt

Thanks for the reply Matt.

My setup is not DSP .... so my radio/CD unit sitting above the MID is directly powering the speakers. My pondering was on relocating the whole lot of MID and CD/radio to the glove box area so that its all still in the car and working and listening to the ibus. That would then leave me the space to install some sort of carpc setup in the space where it was. If i did that, all i would need is a setup where the buttons around the new screen could in some way provide the same radio/MID functionality i've taken away. ( i.e. to send the right commands into the iBus )

Great info about the ibus data thank you. I hadn't realised that there was a source-destination part to each command. Would I be right in saying that any receiving unit doesn't really care where there command comes from? i.e. as long as the destination is 68, then the radio will obey the command?

Is your later screen still an ibus setup?

Audio is a whole other set of spanners V8 or else ...

fisha wrote:

Thanks for the reply Matt.

My setup is not DSP .... so my radio/CD unit sitting above the MID is directly powering the speakers. My pondering was on relocating the whole lot of MID and CD/radio to the glove box area so that its all still in the car and working and listening to the ibus. That would then leave me the space to install some sort of carpc setup in the space where it was. If i did that, all i would need is a setup where the buttons around the new screen could in some way provide the same radio/MID functionality i've taken away. ( i.e. to send the right commands into the iBus )

fisha wrote:

Great info about the ibus data thank you. I hadn't realised that there was a source-destination part to each command. Would I be right in saying that any receiving unit doesn't really care where there command comes from? i.e. as long as the destination is 68, then the radio will obey the command?

Is your later screen still an ibus setup?

Audio is a whole other set of spanners

Very interesting. Had a quick scan of it, will need to look closer.

In terns of connectors .... Surely they can be spliced ... If you can tap a resler into it, then why not another connector.

As regards your setup, if you've only swapped the LCD, are the button circuits sill in place, and would they still push out an ibus command when pressed? If so, is there anything stopping you simply having a a separate ibus circuit for just the nav buttons +resler into the pc. That way all your commands are already sent out and you just have to listen to them as opposed to making up a whole new interface. V8 or else ...

No on the later post 2005 range rovers where the touch screen system is fitted the system does not use ibus to communicate between the infotainment ecus so the buttons on my 2008 screen dont operate on ibus so they do not output ibus commands hence the need for an interface to take the button press signal into the computer then the pc can send out any relevant ibus messages. When you start to read that ibus document and other information on the ibus network you will soon realise that the ibus network is brilliantly simple and amazingly complex at the same time in how it works and operates, it has taken me over a year to start to fully understand how it works, unfortunately its not just a case of 'splicing' into the bus and things will work, if only it was this simple. The bus is very 'self aware' for example if you connect a nav screen to your ibus network the screen will start to broadcast an 'im here' signal which the other ecus listen for, so when your nav screen sends this message and also your mid sends its 'im here' message the other ecus may get confused because they will not know where to send there display information. E.g. on you MID you have buttons with 'soft' labels e.g. DSP, audio, volume etc... these labels come from various ecus in the infotainment system so if there are 2 display devices on the network they wont know where to send there info and they will more than likely stop working as on the nav screen version of the system all display info/labels comes from the NAV computer which then sends the info to the TV module which is then connected to the nav screen. All display information for the sat nav version goes though the TV module which is an integral part of the system. Just as is the radio module on the sat nav version, it does not just control the radio its is a pre-amp for all things audio in the car, from CD, TAPE, AUX IN, TV etc... the unit should be called the audio control unit because that is what it does. Just the same as yours will, it will control all things audio that you have in your car.

Sorry for waffling on!

Matt

This video may be some help to you

http://www.youtube.com/user/powerfulukltd#p/u/18/AmgNh6deQAQ

Hi Fisha,
Haven't we been through this before?

Matt, just fyi, the MID head unit is comprised of 2 parts: a CD54 (I have no idea what the cassette version is called - or if it was ever offered. It is in the manual) and the MID which is just the display and buttons/volume control. When I did my nav retrofit, I was originally excited to see that the pinouts for the CD54 were exactly the same as for the BM54. I thought I might be able to save the money on the BM - but it wasn't to be. When I plugged the CD54 in place of the BM - nada. I've never bothered logging the ibus commands off the MID system, but I assume that they are different for the BordMonitor radio. Also AFAIK, DSP was not an option with the MID system - the only option was the HiFi amplifier.

Fisha, there was a site somewhere where a guy built a BMW CarPC using his MID's buttons/internals, building a custom surround for it in the shape of the original nav system, and adding a 7" touchscreen. If you really are serious about this, then doing something along these lines makes the most sense. You can go the same route as Matt and buy a late model nav screen, gut it, add a 7" touchscreen and the MID electronics to the buttons. Add the car PC along the lines of what Matt is doing and you're done.

I thought seriously about doing something like Matt - it became very clear tho that I wasn't going to have the time so I tried to follow the KISS principle. On top of the time, it also became clear that I was not going to be able to save a great deal of money by opting not to retrofit the nav. Man toys are expensive.

The way I decided to go is to retrofit the original nav, add a touchscreen overlay to the screen, and splice the carPC into the system with resler/CIS or similar. With the resler interface, not only can you have the PC communicate with the car, with a VGA to NTSC adapter and a TV Module you have a very cheap interface for the screen: the resler adapter switches the rear view camera input on the TV module on when you switch to tape with the mode button and the VGA signal is piped into the TV module in place of the rear view cam via the NTSC adapter. Sound from the pc is added through the tape inputs in the radio - so you have both PC picture and sound. Add a touchscreen overlay and you have an input device. A car PC front end and you're done. And yes, the resolution isn't great on the OEM screen, but as long as your not trying to read the windows desktop, it's fine. Thats why you have a carPC front end and sw. I have a digital TV module too and my picture is wonderful.

HTH. 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)