As they say, first things first. The main problem I hit was the video signal.As OEM setup, my 2001 BMW E38 is equipped with MKIII widescreen navi, TV module and hifi radio (no DSP).
This setup allows me to conveniently use the composite input of the TV module for PC output. Obviously I discarded this option from the beginning, the image quality is not that great, we all know that. So, I went straight to RGB inputs.
The first stop was the HackTheIBus Yahoo group, an unbelievable community with tons of information on the subject.
Here I learned that my OEM LCD is actually a Sharp LQ065T9BR51LCD (you can find its datasheet here) with a native resolution of 400×240. That’s pretty low, I might add, for 2001 OEM equipment. The truth is the display overcomes this handicap with quality. It works perfectly now, after 7 years in temperatures ranging from -20 deg to +60 deg C and that’s sometrhing.
I also learned that it requires a sync-on-green signal, or RGsB. That is a normal three wire R+G+B signal with sync multiplexed with the green channel.
If you want to know more about video signals (which I did), you can find very good background information on the INLINE INC Tech Center Technical Notes webpage.
So this it the first problem. Any normal PC video card has at least 5 wire signal output (Red, Green, Blue channels, Horizontal and Vertical sync). Most (if not all) of them also have extra communication channel lines, also known as VESA DDC (VESA Display Data Channel, a way of enabling the monitor and graphics card to communicate with each other). That means I must find a way to output this weird RGsB signal … and with that shitty resolution.
A few minutes with Google revealed that THERE ACTUALLY IS such a breed of video cards, made by Matrox. Check out jlitko CarPC project page, he is using an old Matrox G200 in his setup.
Long story short, it took me almost 2 weeks to get my hands on a working PCI Matrox Millenium card. This card was made in 1996 but still rocks. Now for the resolution, the only way is PowerStrip, as it turns out after countless hours of reading posts on mp3car.com. Good thing this PowerStrip is shareware so you can test it well before buying it.
Unfortunately it wasn’t much until I learned that my Matrox drivers will not accept 400×240 resolution and Windows would throw me away with compatibility VGA mode. But wait, there is a catch. If Windows won’t allow me to use 400×240, maybe it likes 800×480 instead. But how can double the resolution work with a 400×240 monitor? Well, we can cut the horizontal res in half by doubling the pixel clock and the vertical res by using interlaced mode. Nice trick, eh? Well, it turns out that Matrox Millenium drivers don’t accept 800×480 either (this may be due to small pixel clocks required). So, there’s a no go here.
I turned to an old PCI ATI then, also without any success with 800×480. 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 with correct timings. Oh … finally! But wait! How am I supposed to get RGsB output on my ATI?
Well, an hour with Google, and here it is: the CIB interface. It does exactly what I need. But wait! 199 euros??? Mmmm… Hell no! I must find something else.
Another few hours with Google and here we go: good info here, here, here and here. The simplest schematic here with good explanation too.
Let’s try it! I bought the parts, I made a quick and dirty setup on prototyping board and WHOA!!! there it is, my first XP background on the BMW LCD. Tadaaaa…. Well, not so fast! The image was a mess. Continuously rolling, with a greenish zombie tint, with poor brightness and contrast but lots of noise, the image was horrible.
Unfortunately another 2 hours of work to make a labored setup of the schematic, with proper soldered connections and good isolation, brought no improvement at all. So this was clearly NOT the way to go. DAMN, that’s over a month wasted on that!
Back to Google again.
November 19th, 2008 at 7:47
Don’t give up!
It can be done………
November 29th, 2008 at 1:26
Was just browsing and found this one, it might be one you are looking for. I am not US, so I can’t say what’s the price, but looks pretty cheap to me…
Good luck!!
http://www.magenta-research.com/cgi-bin/shopper.cgi?preadd=action&key=VIDEVGARGB&reference=/cgi-bin/shopper.cgi%3Fsearch%3Daction%26keywords%3Dvideo%26searchstart%3D0%26template%3DPDGTemplates/Plain/SearchResult.html
December 2nd, 2008 at 2:17
Hi, I’ve been looking for some articles about Hifi-Test. I can see that you too have the same interests. Your post on “Setup plan – the quest for RGsB” is a good example so I hope that you can keep providing information. I wish you every success.
December 7th, 2008 at 6:38
read Article here is here, there all are in detail written.
January 28th, 2009 at 8:46
Great! Thank you very much!
I always wanted to write in my blog something like that. Can I take part of your post to my site?
Of course, I will add backlink?
Regards, Reader
January 29th, 2009 at 7:51
Yes, of course you can!
June 16th, 2009 at 1:12
You know so many interesting infomation. You might be very wise. I like such people. Don’t top writing.