Hi all,
I'm looking for a way to send solid panels of color (Red, Green and Blue) to an NTSC monitor, hopefully through a composite cable.
I've read up on previous times this Forum has tried to tackle NTSC. If it can be done for black and white, is there any way to do primaries?
So far the cheapest thing I can find is the entire Uzebox/AVCore setup, which seems a bit much.
Any ideas?
This is all from the fuzzy recesses of my memory.
NTSC black and white is done by amplitude of the signal, with some timing signals at the end of each row and field.
NTSC color is basically just introducing a higher speed "carrier wave" on top of the signal. At the beginning of each row you establish the true phase of that carrier wave, then in the image part of the row, you phase shift the wave to dial in a certain hue.
I think the Arduino is hard-pressed just to do the timing information for black and white screens. I saw someone had gotten some success at the similar VGA timing. Adding on a phase tweak is probably not something to be done in software. There are surely some analog tricks that can achieve this though.
It is tricky if you want to use a composite video signal or even an RF modulated signal. There are some chips that will do this for you but I have never had much success with them, and that was using PAL. You want to use NTSC which inherently is a lot less stable.
These chips were mainly used for old school video games that plugged into your TV set, search component suppliers for chroma modulation.
Using RGB signals is much easer as it can all be done digitally.