Has any one played with a STV5730A video overlay chip

[Sphere]

Im after some code examples to get me started with the STV5730A video overlay chip has anyone any experience with this chip.

Thanks Sphere.

[Darrel Taylor]

Sphere

I have, and I can say that you'll need to spend a LOT of time in the datasheet. Much more than a normal PIC datasheet. It's not layed out very well.

Can't give out any of the code, but here's one from the Old List...
http://list.picbasic.com/forum/messages/5820/6314.html?

or, here's one for sale.
http://www.blackboxcamera.com/stv5730a/software.htm

Also, I don't think they make those anymore, so if you want to build a bunch of them. You might want a different chip.
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[Sphere]

Just had a look at the code, is it not possible to use shift out instead, it would make it a bit simpler to follow. Ive read about the chip being discontinued do you know of a equivilant chip.

Thanks for the reply Sphere.

[Darrel Taylor]

Yeah, you can shiftout, but it's pretty slow at only 50khz (4mhz osc). The chip can be clocked at up to 2 mhz. Although that routine won't go that fast either.

Don't know of any alternatives.
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[Ron Marcus]

There is NO equivalent IC out there. For that reason, I had to make an OSD board using two '819s a gated oscillator and video sync chip to do the same thing. It was a PIA, but won't go obsolete any time soon. There are some simple circuits posted on the web to do this. This was a starting point for me, but I needed higher res,smaller characters, and three lines of 20 char read out! The gated oscillator was the tricky part, and mine runs at 28MHz to make it all work as planned.
If you find an alternative chip, let me know...
Ron

[Sphere]

Thanks both for the replies. I already have a stv5730a in a working circuit, so I give the code example a go and see how far I get. Ive googled around looking for an alternative but no joy so far. It looks like all current video generation is done via a microprocessor plus software rather than a specific chip.

Thanks again Sphere..

[mister_e]

BOB-3 or BOB-2 modules spring to mind but they'r not cheap.

This week,, and Alain posted a link her on wich you can find some plug and play solution.

http://www.speechchips.com/shop/

Now you just have to figure out how to mix the signals together.

Those solution are simple, but you should stock them... i guess one day they'll disapear... as many other ics anyways

As now i used PICs @20MHZ and LM1881, great to me as now.

EDIT: and this dig-out a really old thread...
http://www.picbasic.co.uk/forum/show...ghlight=lm1881
i knew it reminded me something

[jason]

Hi ya all, Thought I would bring up this subject.

I have a need to overlay video (text only) onto a vga signal. I'm not looking forward to hacking into the sync signals or anything else, I would prefer to keep it simple. And the STV5730A chip is not avalible where I'm at, not to mention its for pal and composite. Although I see in the datasheet something about RGB.

Is there any other chip like a vga monitor chip ment for menu overlay that I could use ???

I have always been fassinated by video overlay And have always been upset at the fact theres nothing half way simple about it.

[keithdoxey]

Hi ya all, Thought I would bring up this subject.

I have a need to overlay video (text only) onto a vga signal. I'm not looking forward to hacking into the sync signals or anything else, I would prefer to keep it simple. And the STV5730A chip is not avalible where I'm at, not to mention its for pal and composite. Although I see in the datasheet something about RGB.

Is there any other chip like a vga monitor chip ment for menu overlay that I could use ???

I have always been fassinated by video overlay And have always been upset at the fact theres nothing half way simple about it.

There are video overlay chips from Sanyo that will handle a VGA signal but if the source signal is coming from a PC then I would have thought that getting the PC to do the overlay would be a cheaper option. XP and vista can both display transparent video over the desktop.

Video overlay chips are becoming a rare breed as the video world rapidly becomes digital. With all set top boxes now being digital all overlay and menus are generated by the same chips that create the video image.

[jason]

I will go search now for a video overlay chip by Sanyo. Its not a pc but is a vga video signal. thanks

[sougata]

Hi,

I have played with software video generation inspired by rickard's pages. Honestly it was mostly copy/paste , but I have always been wondering what would be the best possible way to generate phase locked color in software. I have been trying to figure out whether I should use a video decoder chip (PAL) and get a PLLed osc from there itself to run the micro. It was basically meant to be a logo inserter on video signals (Genlock/Overlay). I have been considering the Propeller chip from parallax. Then again shifting platform for a single project does not make much sense. Cause the propellers are not available in my country and even if I find some they are way too costly than a PIC.

[Ron Marcus]

hittconsulting.com/products/hcosd/
This is a Propeller based module, and is open source with schematics. I believe it will work on VGA too!
Ron

[jason]

We now have much faster pics then way back during most of the projects you see on the web for video. We now can go upto 80 mhz, but thats not picbasic pro compatible. I think the PIC18F46K20 is compatible and its 64mhz. We should be able to do much better projects with video. the lm1881 will seperate both h sync and v sync. and with that, well its just a matter of timming. But it would be nice to have a plug and play chip. The sanyo chip seems like a winner but can't seem to find any here in Mexico. I may just have to wait till I go back to the states.

Last night I used a PIC to double the h sync and it seemed to do pretty good. and it was just a 4 mhz 16f84a. With my new scope the only prob was the pulse came latter then the original, but I managed to get the pulses exactly doubled. but I do need to address the late sync signal. I'm wondering what the heck do I do with the actual video signal (RGB) to get it to shrink to the correct timming? I should do a little more checking before I start asking questions.