Thread: VGA, Composite, TFT

hey guys i need a ton of info.. i want to learn how to use the things in the title: VGA, Composite Video and TFT...

i need links to pages with info on VSYNC / HSYNC and all that good stuff. i have to goto work now but would love as many comments as possible please...

even if you dont understand it but have info on it i will try to learn it and show what i learned here as good as i can...

VGA and Composite Video are the far most important... i think TFT fits into both of those anyway....

so please any info on VGA pinouts, protocols or what ever... post your heart away....


Thanks in advance guys ( and gals )

TFT is really nothing to do with any of those, it's merely a particular type of LCD construction.

What are you actually trying to do?.

You're gonna be hard pressed to display stuff with a microcontroller on VGA. It's probably possible, people have driven NTSC video signals before (which would be "composite" video). However, the capabilities are limited. The PIC can't buffer an entire full-resolution frame, and there's not a whole lot of cycles available to calculate each pixel. But they can display text, simple graphs, or a pong-like game.

just a quick google search gave me this pdf that breifly describes what your after (composite)

http://pdfserv.maxim-ic.com/en/an/AN734.pdf

who said it was for PIC micros? i was going to use a ARM7 device to create a translator type device...

where i can use a pic to talk to the ARM7 which in turn controls the video devices.

now can someone post links for me? heh thanks

I think the Uzebox is one of the more popular 8bit micro projects that use composite video. It uses an interface chip to help with the video.

They have a primer here:
Uzebox - The ATMega Game Console

and the hardware outline here:
Uzebox - The ATMega Game Console

nice i might do that uzebox heh the AD725 is $9 tho heh.. expensive ic... but heh if i can use a pic then why not...

i might just use monochrome for now tho... not sure.. .maybe if i find another solution...

i might do this first seems super simple circuit:
VCR Pong

and color isnt needed right now... heh i would love o just make a small terminal type computer heh.. with sd access and stuff.

would i be correct assuming that a tft doesnt have that same color issue as composite.... i can just load color and sync it?

now im off to read more about tft and vga

Originally Posted by AtomSoft

would i be correct assuming that a tft doesnt have that same color issue as composite.... i can just load color and sync it?

now im off to read more about tft and vga

Like Nigel mentioned. TFT is a type of LCD display, it's not an interface.

I know the Parallax Propeller does VGA. It's one of the favorite applications for it. I've seen some fancy rendered 3d graphics with it and also some dumb terminal style applications.

ok guys understand im new to this and also i thought it was different because:

Composite is a analog thing where DAC is used
TFT has a parallel interface for control which includes color which is all digital no DAC needed.... but has sync like composite and VGA
VGA i havent looked into but i assume its like TFT but more strict with timing and power and such

Originally Posted by AtomSoft

ok guys understand im new to this and also i thought it was different because:

TFT has a parallel interface for control which includes color which is all digital no DAC needed.... but has sync like composite and VGA

No, that's completely incorrect - TFT is a specific technique of manufacturing LCD panels, that's all. It's got nothing whatsoever to do with any kind of connections.

Ok I do understand that but. Wasn't talking about the actual physical difference I was talking about communication/control difference and stuff

Originally Posted by AtomSoft

Wasn't talking about the actual physical difference I was talking about communication/control difference and stuff

TFT doesn't have "communication/control difference and stuff", it's down to the external circuitry that interfaces to it, just as with anything else - it's that you need to interface to.

Basically the TFT is the 'tube' if was a CRT - you don't interface to the tube, you interface to the circuitry that connects to the tube.

Nigel why you killing me here heh what im trying to say is...

Composite is tricky to do color since you need to use DAC

TFT no DAC needed to do color because its controlled via digital interface..