Thread: BMW pre-installed system - TFT ?

I have followed with great interest the discussions about BMW's navigation system and its TFT screen and would like to hear more about installations and specific information regarding the BMW OEM TV module (You've got me wondering if you're screen blanks out when driving with PAL, but not NTSC, can you is it country specific as NTSC blanks out on pre-2001 USA TV modules. Is this the trick that Nav-TV uses to provide "TV in motion" for $400? Anyway, later for that...)

Anyway, the screen is a Sharp LCD screen model LQ065T9BR52, although it seems to also be known as LQ065T9BR51 (last digit is different) and I have a PDF datasheet on the display. I don't have any way to host the file, but I will email it to someone who can or wishes to see it.

If you are a Yahoo BMW Nav Group member, you can get the file directly at:

http://groups.yahoo.com/group/bmwnav/files/

Composite input is generated by a Philips TDA8376H PAL/NTSC TV Processor. This IC is contained within the display unit. Information regarding this IC can be found here:

http://www.semiconductors.philips.com/pip/TDA8376/N1
http://www.semiconductors.philips.co...76_8376A_1.pdf


IC's for providing input to the display/TDA8376H IC per Sharp's LCD datasheet include:
IC3Y29BM - analogue composite video
IC3Y26A - RGB input

These seem to be readily available IC's - from Radio Shack repair parts even, if you can believe that, and fairly cheap as well.

If you care to experiment with the display without tearing apart your car TOO much, the following are some re-phrased comments from "Moni" at Nav-TV (I believe) the provide some ideas for "experimenting" with the LCD screen through the navigation system wiring harness WITHOUT the video module.

"...The video module does not do anything sophisticated with the video. In a setup where the video module is used, the navigation RGB signal passes thru the video module (and it's video buffers) without any type of video genlock.

If you want to experiment, heres what to do:

(Do this procedure at your own risk. don't blame me if something goes wrong. I'm describing a procedure I have done many times in the past year.)

1. Remove the blue connector fron the navigation computer.
2. Remove the blue shell by inserting a small pick into the latch on the side, then slide the black insert out.
3. Note the three black coax cables and mark them as A,B,C.
4. You will have to figure out which cable is used for each color: red, green, blue. Make some notes on paper and mark the pin position of each cable. The connector is marked by pin numbers 1 thru 18 (1,9,10,18).
5. Video signal (coax internal wire) is the clear in color. The coax video ground (shield) is black.
6. Remove each video cable by pressing against the metal latch thru the side of the connector with a pick and pulling the wire out slightly, then repeating again on the second stop, until the wire comes out completely.
Repeat for all six wires (three video and three shields).
7. You'll end up with three loose coax cables. You'll have to insert the blue shell back in place now and reconnect the blue connector to the navigation computer. The screen needs a ground coming from the navigation computer in order for it to operate (It's the same reason why when you press "monitor off" the screen shuts down completely).

*** The above procedure is only given in order to avoid cutting the coax cables. ***

8. Turn the key on and make sure the screen powers up - the screen would turn white.

9. If you'll connect a standard NTSC video signal source to the green video cable, you would then see a steady, green picture (maybe a little dim, but that's OK). On the other two cables, the picture would be rolling blue or rolling red.

10. You'll need an NTSC composite to NTSC component RGB decoder. Today, all decoder are I2C or other bus-based chips that require the used of an external microcontroller to control them (just like the philips TDA's you've mentioned) - that means that a complete microcontroller is needed to be programmed to the right decoder, BUT:

11. You can buy on Ebay (I could not find them now on ebay but once in a while they are there) a commercial or studio NTSC decoder. Some work internally on 12 to 15 volts... They are rather big ( 1U rack size) but they perform superbly. Most have sync on green as well as seperate sync. You would want to get the "sync on green" type.

//See my comments regarding IC's IC3Y29BM (analogue composite video) and IC3Y26A (RGB input)//


12. VGA RGB does NOT work! It's non-interlaced video with double the scan rate. You can try, but you'll get two pictures, wrong colors, and bad sync on one monitor.

13. When you're done experimenting, slide the pins back into the connector. They should latch back in place and everything would work again as usual.

Moni

NAV-TV Team..."


Taking this information a little farther, consider...

Creating a little "BMW Magic Box" primarily consisting of the IC3Y29BM (analogue composite video) IC with a few dip switches to select PAL/NTSC and some other LCD specific options, a (remote controlled?) switching relay to select between navigation and external video sources and video input connectors. To make the "box" even easier to install and more convenient, consider power output sources for 12V DC on the "box" with "always on," "on with ignition on" and "lights on" dedicated power outputs.

Overall, the "box" should be fairly simple and, fitted with the right BMW specific connectors, should install in less than 30 minutues.

To install, you'd need a small screw driver and a few other basic tools for removing connectors and panels, your camcorder or a video camera (i.e., reverse/back-up camera) and a TV-tuner/AV controller with diversity antenna system (optional) that you can get on eBay for about $175.00 or less.

Starting in the trunk, carefully open the panels to the navigation system and remove the blue connector from the computer and plug it into the "box," then connect the blue connector from the "box" into the navigation computer.

After affixing the "box" to the trunk panel with its velcro strips, connect the small wiring harness from the "box" to the power inputs for the computer using the wiring harness provided, then connect the separate harness from the "box" to the backup light cable as illustrated on the instructions.

Connect the TV-tuner/AV controller into "Input 2" of the "box" with standard RCA cables and the power cord from the TV-tuner/AV controller into one of two 12V power outputs on the "box." Loosely connect the diversity antenna's to the TV-tuner/AV controller for now; you can more professionally afix them later.

Connect your camcorder (or the back-up rear view camera if you purchased it from Nav-TV) to "Input 1" on the "box," turn it on and point it to something in the garage. Start your BMW and put it in reverse (pressing the brake of course) and you should see what your camcorder sees on the navigation screen in reverse. Slide the gear shift back to park and the navigation screen should return to its normal display.

Now, tune the car's radio to one of the FM frequencies specified on the TV-tuner/AV controller instructions and turn on the TV-tuner/AV controller with its remote control. Using the remote, seek a local TV station. The navigation screen should change to TV and the sound should come through your FM radio. Put the car in reverse again, and the screen should display the (reversed) camcorder image again (and you can hear outside sounds as well if you want); put the car out of reverse and the navigation display should return to TV.

You now need to run the provided combined wiring harness from the "box" and the TV-tuner/AV switcher to the back seat area (up to 2 video outputs are available) and install a discrete switch under the armrest that switches the navigation display from its normal mode to video. Running this harness is probably the most labor intensive part of the installation.

Reverse view is automatically controlled for the navigation screen so no additional controls are needed for that and the 2 rear seat video outputs always display the video input, but not the navigation system screen data (unless you want to do some very creative wiring).

A small video camera can be installed near the license plate and connected to "Input 1" of the "box" where the camcorder was connected for testing. If you do not install the backup camera, no switching of the screen will take place.

Next you can connect up to two 7" wide screens (optional) to the terminated cable harness for the back seat passengers and plug in a DVD and/or MP4 player into the TV-tuner/AV controller in the trunk.

For the technical, the "box" is a microprocessor (powered by an interconnecting cable to the navigation computer power input cable) that converts composite NTCS video into RGB outputs for the navigation screen. It also contains a relay that switches the navigation display from its normal mode to "Input 1" when a video signal is present (i.e., power is provided to the backup camera for reverse viewing) and reverses the screen image. When a signal is present from "Input 2" (i.e., the TV-tuner/AV controller) and the "discrete" switch is on, the navigation screen displays whatever is on that source; when the "discrete" switch is off, the normal navigation display is seen.

And you can fairly quickly disconnect the "box" and all its attachments and reconnect the original wiring just as it came from BMW if you need to.


You'd think we could find SOME smart electrical engineer who we could push a reasonable amount of cash at to create the "box," wouldn't you??