The idea of building a carPC for my E38 is bothering me for some time now. The fact that, as weather gets colder, my CD-changer starts to show its age by refusing the CDs one by one adds to the problem. Now, to conclude, it has failed me completely by not recognizing ANY kind of CD. Carefully opening it and painstakingly cleaning the lens did not help.
"Well, it's time to put that wide display to a new use, it's time for a carPC!" I told myself. After countless hours of googling and documenting, and after a few new dozens of bookmarks in my favorites folders, I have returned to mp3car.com as the best possible source of information. I have found here answers to most of my unasked questions as well as an extremely well formed community of pros.
So, this is my first post, with a new thread!
First of all I have built myself a list of requirements for my future system, and with it, a list of problems, of course.
The prime issue here is the video signal. My 2001 BMW E38 is equipped with MKIII widescreen navi, TV module and hifi radio (no DSP). I discarded the option to use PAL/NTSC input from the beginning. Of course, the TV module is an advantage, but the image quality is horrible. Therefore I went straight to RGsB input. I've got the basics from here and here.
For testing purposes I found an old (1996) PCI Matrox Millenium card (the only brand that seem to output sync on green in hardware) and I started fiddling with PowerStrip. I didn't know much at that time about vga signals but everyone's got to learn and learn.
It wasn't much until I learned that my Matrox Windows drivers will not accept 800x480 resolution and would throw me away with compatibility VGA mode. I turned to an old PCI ATI then, also without any succes. Even my old trusty ATI Rage128 AIW refused the resolution! Than I remembered that my laptop has a somewhat newer video card with dual RAMDAC, one for the onboard LCD and the other for the VGA connector. The R300 on that laptop accepted the resolution. I quickly built an adapter cable for combining csync with green and started working with powerstrip onsite, on my car.
After a terrible icy afternoon, I managed to get the settings right for powerstrip and I've got my first XP background on the OEM LCD. TADAAA!!Only than I could finally understand how can I send a 800x480 image onto a 400x240 fixed freq screen!
Well, part of the "video problem" being solved, here comes the hardware.
From the start, I must tell you that I am NOT a fan of Epias. So, I have chosen the uATX format. It is far more manageable and flexible. I am thinking a small uATX AM2 board with Athlon64 is the best option here. I want to use a 4000+ Orleans CPU, underclocked to about 800MHz with 0.9-1V vcore. That setting will transform the heat of Arizona into a gentle breeze of Miami, I think, in terms of heat production. It will also bring me much power economy.
And here comes the first question. I have to choose basically between Asus M2N and M2A series. That is GeForce 6100 and ATI Radeon x1200 GPUs. I have to limit myself to onboard graphics because the allocated trunk space is limited. Which one of the board is more flexible in terms of custom resolutions? Should I choose ATI (one of my favorites) that I know supports powerstrip and outputs Csync, or nVidia (never used it before, but I read that it has native driver support for custom resolutions).
This is the first problem I need help with, guys! Thank you in advance!
Bmw Lcd
Coolshark,
WELL DONE, GOOD JOB!
I am trying almost the same thing in my MINI COOPER S.
Test setup using NEC laptop, homemade VGA to RGsB converter, feeding the NAV displays RGB lines.
What Powerstrip settings work?
I have tried various with 800*480 resolution and I can get a very quickly rolling display but no stable settings.
Does the unti need an interlaced feed?
Many Thanks in advance for a reply.
Chris
MCS
Warwick
UK
Hello Chris. Due to the fact that this thread is almost 2 month old, I have given up the hope that anyone could have actually read it! Well, I'm happy that I'm wrong!
About the VGA signal I've got, it is good, the image is stable, but the quality of the image is poor. This is due to the poor quality cables I used (cheap unshielded ones) and the adapter itself, which is ... simplistic at most. But for the beta stage I am in, is it good. You see, I haven't got the hardware just yet. I am still working on the adapter, and without an oscilloscope it is pretty hard.
The PowerStrip settings that worked for me are: 800x480=800,36,64,124,480,60,3,34,16002,312.
A setting also reported to work here is: 800x480=800,41,56,119,480,25,3,32,15658,175.
Anyway, if you study for a little bit the timings in PowerStrip and compare it to our LCD specs you will find out that we are using twice the required resolution (the LCD being native 400x240). In practice this only works by squeezing horizontal data by doubling the pixel clock (16MHz instead of native 8MHz) and squeezing vertical data by using interlaced signal. So yes, we MUST use interlace. The one most important parameter seems to be vertical sync width of 3. All the other parameters can be adjusted with small margins.
I am very curious about your homebrew adapter. Did you actually measure the signals it sends? How does it perform? Can you show me the schematic?
About the status of my project, I am struggling now with the software configuration. I decided to use Winamp for audio and MediaPlayer Classic for video. Because BMW LCD does not have touch screen I must find a way to control them with standard BMW buttons and knobs via i-bus. ibuscomm is a start, but it is too limited. So, I started working at an application to do that.
Basically I am using a FLASH platform supplemented with Windows API access to read/write the serial port and Windows sockets. The idea is to have an app that will intercept ibus messages and convert them to standard WinLIRC messages. This way I can control any application. The software will also answer the polling data from the radio to simulate a CD-changer. It will also display OBC parameters, it will interface with IKE to display Winamp title/track on the OBC text bar it will manage GPS tracking and logging, etc. It will be in essence a touch-screen disabled, ibus-oriented, front-end.
Anyway, because I can only assign only a few hours every weekend to the project, it is advancing slowly.
So, please tell me more about your configuration too, hardware and software. What have you got and what are you planning to do? How are you planning to power up or down your laptop?
Hello Coolshark,
I am glad you are happy I have taken an interest in your post.
I thank you for it as it has helped me no end.
To answer your questions.
My VGA to RGsB adaptor is the same as your current one, I made it using an old CRT VGA cable connected to a small Veroboard circuit and on to the display RGB cables.
I can not measure the signals as I don't have acees to a scope, so I am flying a little blind.
Yesterday I had success getting Powerstrip to output the correct signals.
My problem was a graphics card that could not output an interlaced signal!
One new card (GeoForce4 MX4000) later and I get a desktop on the screen.
It's a little dark and green so sounds like I have similar problems with cable quality as yourself.
Planned final setup is to install a small mobo in the CD changer enclosure in the boot with display output to the NAV screen.
Input will either be an overlay touchscreen (yet to find a suitable sized one!) or IBUS interface to the rotary controller on the NAV screen.
My car does not have NAV computer so can't interface to it to the screen.
Software is unknown yet.
I too wish that I could spend more time on this, howver a new little daughter is a big good distraction.
Lets keep in touch here ? to exchange information as I am always willing to help (and be helped) by other BMW fans.
TTFN
Chris
Be careful Chris! If your image is a little green that means you have a little too much sync signal into the green line. Without proper signals you can easily burn the green channel amplifier and bye-bye LCD! Not to mention that is an EXPENSIVE piece of equipemnt. That's why I have stopped working on my adapter until I can get my hand on a scope.Originally Posted by chrislamb
Are you sure the mobo can fit into the enclosure? I have opened mine once, and a lot of space is taken by the shock-dampening system BMW has decided to use! I'm afraid the mobo has to be pretty small.
Yes, I have thought about an overlay too. You can find a very good one here. But for me, I am afraid it is a no-go. The overlay is pretty thick (about 1mm) and the actual space between the display and the bezel is almost non-existent. I would have to make serious modifications to the bezel. Not to mention the sliding mechanism of the LCD which would have to accommodate the connector strip. I hope your LCD is more manageable about that than mine.
Anyway, I am curious: without a nav, what image do you get on the LCD? Do you have a TV module? Where do you get the BMW user interface from?
And most of all, where is your display located? Can you post a pic? I have seen a lot of Mini pictures on the net, but none of them with a LCD. I was wondering, where could it be located?
Well, keep in touch!
Integrating carPC with MINI R53 wide OEM nav LCD
Coolshark,
Thanks for the warning about too much green.
I think I need to feed the Csynch signal into Green using a resistor to reduce the voltage or use a better VGA to RGsB circuit?
I connected Sync earth to Green Earth, could this be the problem?
I don't have a CD multi changer in the car just the bracket which holds it to the side of the boot area, its item no. 1 here :-
http://www.realoem.com/bmw/showparts...04&hg=65&fg=10
This should allow the use of a standard 26cm by 23cm MOBO as I can use the small storage compartment next to it in the car for the PSU etc.
The touch panel you have linked too is too big for the display ?
I am trying to get this one:-
[media]http://www.magictouch.com.tw/download/products/pdf/4%20wires%20flat%20for%20lcd/Ac15790.pdf[/media]
Which is only 1mm bigger than my display and can be driven with a standard USB driver.
The display is yet to be installed in the car and without Navigation computer it will only be used for CarPC.
I bought it from a local car dismantler.
In the MINI it replaces the center speedo when fitted, see here :-
[media]http://www.windowsfordevices.com/files/misc/cebit-mini-dash.jpg[/media]
TTFN
Chris
Sorry the link to the Touch Panel fell off somewhere.
http://www.magictouch.com.tw/downloa...cd/Ac15790.pdf
OK this time ?
How about this Csync circuit ?
[media]http://www.nexusuk.org/projects/vga2scart/schematic.png[/media]
Hmm surprised this is not a more popular thread as I can imagie there are quite a few BMW owners with the factory fit screens wanting to put PC's in there.
Yeah, I've seen it before. I haven't tested it but I doubt it works as expected... The voltages on the sync lines are pretty small and I doubt that a simple polarized transistor would do the trick. A field effect transistor may be required.
Anyway, the circuit is only a part of what's required. It only creates csync from hsync and vsync, it DOES NOT multiplex it with the green line. For me personally it is of no use, my video is based on ATI, which can be configured to output csync directly.
You're right Enforcer, I am surprised too. This may be due to the fact that "normal"BMW owners just use the composite video input (the input from the reverse camera) and so, they don't bother with RGsB and stuff...
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