Composite to VGA converter Circuit

Build??? Forget it, just buy one. And they're not expensive. They're like 99$, you can't even buy a good soldering iron for that. And you'll need a lot more than basic knowledge to pull this project off anyways.

Good Luck!

Just find a good school, sign up for whatever courses you need, and Go For It!

Cheers! Rich

I've been looking for something similar, with no luck so far. I have a pick & place machine which uses a B&W composite monitor (it has a single BNC connector) for the vision system. My suspicion is that this is only the "Y" portion of the composite. I've been wanting to replace this clunky old monitor with a standard flat panel, but most of the cheaper monitors only have SVGA.

I'm not sure if a standard composite to VGA adapter box will work.

Any thoughts?

Chris

I have an old PC (233 MHz) with the SAA7114 video capture card hooking up to a video camera. It capture approx. 3 frames per second and store them in a file server. I am using a standard SVGA monitor (flat panel can certainly work). I don't see why you can't do the same.

On Mon, 04 Dec 2006 17:47:52 GMT, "Rich Grise, Plainclothes Hippie" Gave us:

What he needs is an LCD TV, NOT an LCD PC display.

What probably hasn't been explained to you is the complexity of pulling apart the composite signal then reconstructing it in to VGA (which is a form of RGB format).

The most popular way is to digitise the composite video in to a video frame buffer... and the reconstruct the VGA (RGB) analogue signal.

So you are going from analogue (composite) --> digital -->digital process-->analogue (VGA).

This is a very high speed process and surface mount IC's with 100's of pins or more.

Not recommended for Newbies!

Now that I have steered you away from the design have a look at Averlogic AL251

Averlogic wont talk to anyone unless the Volume is 10,000 pcs or more.

Just my 2 cents worth.

Joe

If you're still interested, read my post "Digital processing of analog TV broadcast". I should have a working prototype in about two weeks (I better, or I'm in trouble...). The first posts lists all the "blocks" you would need to build/buy. You wouldn't necessarily have to do it the way I am (digitally). But if you want to, you'll have to do a lot of surface mounting (plus make a PCB), or buy a starter board with the FPGA already hooked up. Either way would cost considerably more than buying something off-the-shelf, unless you have surface mount and PCB equipment already.

Or, you could read some of the posts by other people (in the thread I mentioned), who suggest analog chips to get the job done. There might be some hope in doing that cheaply, but you'll have to do some design work on your own. I don't think many people have published a complete "guide" to doing it that way.

But unless you are interested in this for the challenge, just check eBay. I think there are devices under $50 to do this. However, make sure they have a good comb filter - 2d/3d adaptive. You will actually notice the difference if they simply use a notch filter etc. No TV's nowadays do that (that I know), but some converter boxes and cheap PC tuner cards still do.

The BEST solution would just be to buy a better cable tuner box. You'll need one anyway, of course. Might as well try to find one with VGA or DVI output instead of just composite. I don't have digital cable, but I think you can find digital cable boxes like this. Some modern TV's actually come with such inputs.

Good luck Sean

Just thought of one more thing. If you can even find a cable tuner box with COMPONENT video out (instead of composite), preferably with progressive output, then converting to VGA is a *lot* easier. I don't really buy the newest-and-best entertainment systems, so I don't know if this is common. You'll have to check or search google. If you find one of these boxes and are willing to buy it, I'd recommend starting a different post called "Composite video to VGA", and you might get more responses.

(Reason: For component video to VGA, you don't need a comb filter, chroma subcarrier lock, or QAM demodulator. You just need to extract sync and properly weight R, G, and B. I'd be extremely surprised if there weren't single-chip solutions to do that.)

Sean

The fastest way

Otherwise if you like building things. I have a circuit somewhere which we used that converts NTCS to VGA. If you don't want to buy anything all ready then I'll send it to you at your gmail address. The circuit we used decombines the horizontal and vertical sync signals and doubles the horizontal scan rate to the standard 31.47KHz or something like that, VGA standard by a reading process of a PLL at twice the write frequency of the A/D converter into a buffer memory. We used 3 6 bit converters for the RGB digital output and another 3 for the digital to analog conversion at the monitor input end but later discovered that 8 bit ones worked much better. Care has to be ensured in keeping noise between the modules down. The more space you can get between them the better they work.

BTW 17" LCD monitors that work as TV's in my area cost only 50 bucks more then the 17" LCD monitors. Is it worth all the hassle building this stuff? And they cost only a bit more then 100 bucks the converter modules given above.

The modules I gave above are not proffesional level equipment because the prices will be well above those levels but a lot depends on whether your eyesight can tell the difference! IMO your image still looks better on your TV or get the LCD/TV combo.

lemonjuice

On a sunny day (Wed, 06 Dec 2006 10:28:26 +0100) it happened lemonjuice wrote in :

Seems that only has RGB out, that would be 15625Hz and VGA wants double that H. that is jus ta NTSC / PAL decoeer, analog (note what looks like the delay line).

Hell for that money here you can but a small color TV with teletext and SCART (RGB ?) out.

That one is indeed VGA out, a lot more complex.

On a rainy and wet day On Wed, 06 Dec 2006 10:57:32 GMT, Jan Panteltje happened to say out :

Lucky you that you got sun there.

They are quite cheap here

Assuming you don't mean butt but buy. A scart signal usually has combined Horizontal and Vertical scan signal. You need to seperate those for monitors.

Maybe you like this one

lemonjuice

On a sunny day (Wed, 06 Dec 2006 12:26:47 +0100) it happened lemonjuice wrote in :

It comes and goes, now comes, I am up the roof fixing it. Last week wind force 8, now they predict it again.... weather radar show showers generating upwind..... But 10 degrees C in December, I love it (could be -10 for that matter, for the US guys: 0 C means freezing).

Yea sure, I type this between other things, never look at the screen.... (ahum).

Eh.... The VGA monitors will not work on SCART anyways, because the H freq range does not allow down to 15625 Hz.

I like it, it is what the OP wants to make, but he wants it as exercise in FPGA. Sure cannot beat that price.

On Wed, 06 Dec 2006 11:42:59 GMT, Jan Panteltje Gave us:

I noticed it doesn't mention what the output res is. Also, it just says "high resolution output picture".

So it would be 640 by 480 or a 720 by something array size.

Hopefully the latter.

I haven't used the following, but...

TV on LCD (or any monitor):

it's $37, including shipping, if you pay with google checkout.

sean

On a sunny day (7 Dec 2006 22:56:11 -0800) it happened sp snipped-for-privacy@yahoo.com wrote in :

Impressive.

I was arguing against PAL in FPGA elsewhere in the discussion with the OP. (against doing PAL / NTSC demod digital), and I just found a warning in a German TV station (Vox) news bulletin that states: 'Test HDTV receivers before you buy these on a normal PAL transmission, as those are still the majority you will view, and many of these new receivers show horrible PAL pictures'. It did not say if it was due to rescaling errrors from PAL to 1920x1080, or decoding errors, but clearly even these high end manufacturers either had no full size clue, or did cut corners. That probably can be traced down to chipsets used...... But now they can say: 'See how bad analog PAL was compared with HDTV?' Chances are that if they ever looked at analog PAL in the studio they would think it was HDTV :-)

Video is all f*cked up, nobody has a clue, like audio, speakers with 1000W on a 12V 2A AC (or DC if you must) adapter, mp3 audio, soundblasters EMU10k1..... TUBE AMPS. And 400 000 gates FPGA PAL decoders while you can do it _better_ with 5 transistors. People are afraid of tuned circuits and inductors and trimpots. But OK mpeg2 rules..... makes little differerence, never did..... looks bad but they tell me it is better, so and I payed for it so it must be.

It is a bit like buying a Volkswagen, and then reading all the Volkswagen adds that show you how great Volkswagen is, to stabilize your self respect so you convince yourself you made the right choice. Even every time the Mercedes overtakes you .

ISTM if you have a monochrome input you only need a sync detector

something might be salvagable from an old TV....

On a sunny day (9 Dec 2006 01:11:33 GMT) it happened jasen wrote in :

No, the VGA monitor will not work with TV line frequences (15625 Hz), check you moniotor specs.

That might be a bit of an overkill. Think about how a color TV set works. The demodulated signal is essentially in composite format. The set's internal circuitry has to separate the individual color signals and extract sync signals from that.

There are probably some one chip (plus a few discretes) solution for that suitable for sub $100 analog color TV sets.

All this assumes the use of a multisync VGA monitor so as not to have to fiddle with scan frequency shifting.