eightboy

If the Navigation Unit accepts RGB+composite sync, it should relatively be easy to convert a VGA output to RGB. The LCD should have a fixed horizontal frequency and refresh rate. Modern video cards can easily adjust such properties, so it should not be a problem.

VGA outputs Horizontal and Vertical Sync and these can be combined with a simple AND gate to get composite sync (a $0.50 part at RatShack). And the RGB signals can be connected directly. Some good video cards can even output Composite Sync on the HSync signal from settings in software; this would be even much easier by simply connecting the HSync to Composite sync.

This would be a cheap solution with excellent quaility to connect a VGA output to the Navigation system. Rather than converting VGA to composite video (degrationl) and then composite video back to RGB (even more degration) with either a TV tuner or NTSC to RGB converter. It is even possible, with a little more complicated circuit, to convert component video (almost every DVD player has it) to RGB+CSync (just seperate the CSync signal from the Y output).

Before I start experimenting, does anyone here knows the specification of the LCD? Resolution, refresh rate, and horizontal frequency? These are the critical information to make this work.

truemagellen

This is what I am also looking to do but not quite sure where to start...I'm glad you are looking into it (and from your post know what you are talking about)

I would be interested in a VGA input…I think you are right that we can do this without complex conversion that severely degrades the signal…

As of right now I would love to hookup a hacked xbox through Component Video Out to the RGBs with virtually no conversion except for what you said (a nice clean signal)…BUT if you can get the VGA to RGBs conversion then I know where I can find a very good box that takes component video and sends it into my monitor (vga) (but would like a direct component to rgbs as well)

As for the LCD specifications…I’ll try to find them for you…talk to ‘thew’ he is very knowledgable and I bet would be VERY interested in a direct vga to rgbs hookup or component to rgbs hookup

Also just so you know another member has taken his nav unit apart and put a touchscreen ontop of the lcd to hook up to his carputer (a computer he made) I think the members name is pmantichrist or antichristpm something like that

antichristpm

I been working on this for a while now. If you do a little searching you'll see quite a few posts of mine about this. My cheap solution was the ATI vga to mac (not mac to vga) monitor adapter. It does the H/V sync smooshing to composite for you and runs a whopping $1.50 [plus shipping]. However, I am still working on getting the right frequencies to get the LCD to work properly. I've gotten an image up there but out of sync with double or quad images etc. Also I had to use a Y adapter and plug a second monitor in to get my computer to use it for the monitor sense pins that aren't used if you just hook up RGB+S. I ordered a cheapo old skool mac to vga adapter w/ dip switches to see if this circumvents the monitor sense pins. Otherwise I have to figure out another solution.

On a side note I am more than confident I forgot to try powerstrip in the "arcade mode" of 640x480 at 30hz. Pretty positive that's the freq. this LCD will work at.

eightboy

Ok, I know that ATi Radeon cards, 9 series, do have the ability to output composite sync on the HSync signal in the VGA (and DVI) output which is controlled by software. These are the ones that have a DVI output. Guess they added this feature to support wider ranges of LCDs. Most LCD manufature's would use standard inputs: digital (DVI) or analog (RGB+sync). Its just a matter of wiring and plugs that are different.

So with an ATi Radeon card, all I need to do is connect the Red, Green, Blue from VGA output (or analog pins from the DVI output) directly to the Nav's Red, Green, Blue signals. And connect the HSync output from the VGA (or DVI) directly to the CSync on the Nav.

For other video cards, a simple HSync and VSync to CSync converter can be built. Too lazy to sketch a schematic (and reinvent the wheel) when such schematics can easy be found with google.

Maybe I should just do the connection with an ATi video card and play around with properties (refresh rate, horizontal sync, interlace option, and resolution) until I get a visible picture on the LCD screen. Since the signals dont connect directly to the LCD drivers, I dont think any high frequency syncs can do any damage. It might drive the LCD controller crazy, but will not cause any damage.

antichristpm

Um, just like I said. I've already done this. The two problems I've come into are as follows:

1) Your vga won't detect a monitor on the line with just RGB+S hooked up. Therefore no signal will be sent.

2) The scan rate of the LCD is 30hz. Positive on that one. 60hz gave me double images as I stated.

I'm fairly sure the resolution is 640x480. Though I'm sure it'd compress an 800x600 signal if you fed it at the proper freq.

DUGS_REX

Video cards are not capable of "knowing" the proper H and V freqs for any monitor that is connected with only the RGB and sync signals. Most modern computer monitors have an i2c serial interface that allows the video card to poll the monitor for information about it. Thats why the monitor name magically shows up in the display prefs panel. This method of knowing what kind of monitor is connected is an extension of something Apple did a long time ago with their "sense pins" used to identify the monitor connected. Since the Nav unit and monitor are a closed system; there is no need for the Nav monitor to ID itself to the Main unit. Any Carputer would have to be programmed to set the Video Mode in software when the computer boots and some cards would require a "dummy plug" to fool the video card into thinking there is a monitor attached in order to generate any signal at all...

antichristpm

I hate to prove ya wrong there, actually wait a tick [I love it]. But I solved our dilima last night. All it took was $.99 cents worth of parts too. Here is your parts list:

3 75ohm resistors <--- $.99
1 two way vga splitter
1 ATI vga to mac monitor adapter

Take the 3 resistors and short pins 1 w/6, 2 w/7, 3 w/8. Basically your RGB's. Viola, your vga card will now detect a monitor attached. From there you can hook up the other end of your splitter to the vga to mac adapter to derive signal.

Now I'm gunna try some higher value resistors so that I can get a bright a signal as possible while still fooling the vga card into thinking there is a monitor hooked up.

Eventually I am gunna do a write up with this along with my how-to-add-a-touchscreen overlay to the LCD. Which btw, works lovely.

Sin,
-Paul

eightboy

There are old monitors that uses ID pins to tell video card what it can support and then there are newer monitors that uses DDC to provide more detail information to the video card. Videocards dont have to use DDC (plug-and-pray monitors) in order to output signal. If you dont have your video drivers installed, you still are able to output something (just lower resolutions). DDC is just a feature to tell the video card what the monitor can support so that software will not output such a high resolution and high sync to burn the CRT (the reason why you cannot output resolution higher than 800x600 without proper drivers).

Videocards dont just support one type of monitor and they can be fooled easily. You either pull the ID pins low accordingly to let them know that a monitor is connected or simply put a load on the RGB signals like what antichristpm did. Putting a load on the RGB signals may not work on all videocards, but at least the ATi's I've been working on.

antichristpm

Just an FYI this worked on my Radeon 7500 mobility in my Alienware 51M and also with my 9700 Pro.

Sin,
-Paul

MrWigggles

The serial lines on a VGA cable are for plug and play support. Most video cards will work without those lines. Using powerstrip those lines should 100% unneeded.

For RGBHV the minimum number of signal connections is 6. R+,G+,B+,H+,V+ and one common ground. RGBC is 5 connections minimum. Now for the best video you should use seperate grounds for R-, G-, B- but it isn't 100% necessary.

In general you want to avoid Y cables because they screw the transmission impedance up and doubles the load on the source (video will be darker then it should be).

Also for short runs at these low dot clocks, you can use CAT 5 for your cable without any problems and don't have to worry about complexities of coax wiring.

http://www.avsforum.com/avs-vb/showt...ighlight=rgbhv

-Mr. Wigggles

truemagellen

antichrist pm...how is your touchscreen addition to the factory display going? and did you figure out the VGA to RGBs thing...the write up you mentioned you were doing

also did you finally figure out what the monitor is running at (frequency...resolution...etc.)

I'm looking for a Component Video to RGBs solution and I found a few converters but they are expensive and I don't know if they will work with our monitor (due to freqs. etc)

antichristpm

Unfortunately for you but good for me, I took a much needed vacation to Burning Man before I got complete with my work. For now there is a patch adapter hooking my NAV RGB+S cables together for temporary use of my NAV system. However I still haven't had a chance to go through all the frequencies to find the working one. But at least the monitor trick with the resistors and a two way is allowing me to do this. If you don't know what I'm talking about you'll have to find my post about that elsewheres. The touchscreen does work fine but took a bit of hacking metal to get it totally flush with the LCD not to mention get it in there without pinching a corner(s) causing a mis-calibration of the touchscreen. I WILL try to post my results because now that I'm back it's one of my top priorities again :-).

truemagellen

thanks PM for the update...I'm still trying to decide on a computer/xbox or both (hacked X of course)

antichristpm

Okay, here is what I've found so far...

1) Our LCD's are NOT interlaced (yay!)

2) They run somewhere around 60hz vs. 30hz as I originally thought (as an interlaced resolution would provide).

3) The resolution is xsomethingx480.

I pulled my hair out for 3 hours last night fiddling with frequencies trying to get a properly aligned image up on the screen. The best I got was a 640x480 image cut into four pieces w/ black bars in the center. This means I'm on the right track but from what I can tell I need the proper resolution to feed into this damned thing for it to line up properly.

My next step is to borrow an oscillioscope from a friend or tv repair shop to figure out what the NAV system is trying to feed the screen. The fun part will be trying to separate the composite sync into the H & V sync's separately.

Any help is appreciated people.

truemagellen

the work you are doing is amazing (missing college: I had time to burn and access to all my electrical engineering friends)...

I suspected our display was progressive as I can pick out interlaced (I have a disorder where I can see screens refresh if they are not a high enough hertz or frame rate...and if not it will make me dizzy and disoriented, ie don't take me to IMAX I'll hurl)...I am so glad you verified this, thank you

I'll try to get some info to help in your investigation but I was curious...since you have pulled out the entire nav display do you notice any serial numbers/model numbers/anything really that could be of use to find an OEM part in japan?

thanks again for your work...you are working on stuff alot of us could only dream of doing

antichristpm

When I pulled the screen out it had only a single number that would have been of any use in which I Googled the **** out of with no results. I passed the number to a few friends of mine whom are also good at research. Nothing...

However, our only saving grace is that we know this system is the DV2300 made by Panasonic. I'm going to do my best to pester them for information about the LCD.

Alternatively... if anyone is ballsy enough to ask (and get a reply) from the folks at avelectronics.com... I'm sure they know what the frequency this motherf&%#!@ is looking for.

Also for those of you wondering just how the hell I plan on switching this from NAV to VGA input after I get it working... I already have that covered too ;-). Took $40 of parts and is now wired to a push button next to my DSC.

If you would like to contact me while at work or otherwise I have IMs:

yahoo: antichristpm
aim: antichristpm
msn: antichristpm@yahoo.com

Sin,
-Paul

Speed Racer

Paul,

Do you have any pictures of the LCD?

I mentioned this project to one of our software engineers and he said that he could probably figure out the specs by just looking at the connectors and any markings that are on the LCD.

antichristpm

I'll post what I have on my camera later. I was going to do a write up on the touchscreen mod but have been delayed by getting a picture on the damned thing.

antichristpm

Ok, I went home during lunch to try another hunch and I HAVE A PROPERLY SYNC'D IMAGE ON MY LCD!...

But... (there's always that but huh?).

I was only able to get it sending an 8bit/256 colour signal to the screen.

And, furthermore, I've proved my original theory correct and one of the last posts I did wrong...

I sent a 15khz Hsync, 30hz Vsync interlaced 8bit signal to the screen. It lined up perfect and the pixelation wasn't that bad either.

So now I'm totally confused... I need help.

Tonight I'm going to try a different model laptop and some of the same freq's I've done in the past.

Sin,
-Paul

truemagellen

there is a good possibility it only takes 8bit/256 color...like old school monitors
that would suck...but I have faith in you!

antichristpm

There's no way it only accepts 8bit. Folks with the avelectronics kits are proof of that... However... it could be that it only wants 12 or 15bit

Sin,
-Paul

antichristpm

PHARK!

Okay... 15khz H and 30hz V interlaced IS the way to go... you'll have to do some slight adjustments but it should work all the way up to 800x600. Though the native res is more like 480x234.

My problem is my laptop won't put out a proper image in any resolution over 640x480 8bit colour. If I go over I get a mouse cursor that looks fine and dandy but the rest of the display is something out of an Atari video game from the early 80's. Therefore I have to get a different laptop w/ a video chipset that wants to play ball.

**** **** **** **** ****...

Those of you that find this info useful good luck.

Sin,
-Paul

truemagellen

thanks Paul...lets see if we can work up a unit that does the conversion to these specs...I'll look into it..thanks for the specs

as for progressive scan, is that a no go?

antichristpm

Since I tried numerous resolutions at 60hz (equivilent to progressive) and there is no option in the driver set for progressive specifically. I'd have to say I'm not capable of doing this. Doesn't mean the display isn't but the image alignment was always off. I'm going to try yet another laptop tomorrow and see what I can come up with then... It's good to be the I.T. man where I work and gives me the ability to borrow a few things.

Sin,
-Paul

truemagellen

hey Paul how is it going lately...I cam across this...which shows some interesting info that seems to be similar to your posts...check it out:
http://www.epanorama.net/circuits/vga2rgbs.html