Open Source/Freeware Budget USB DAC

[keeperx]

From a IT professionals point of view, 24 bit color is 8 bits per channel or 16million colors.
in computer display we have even more colors because we have an alpha layer that adds an additional 8 bits for 32 bit color.

I hope understanding that from my perspective helps to remove some of the ambiguity.

[mixedgas]

From a IT professionals point of view, 24 bit color is 8 bits per channel or 16million colors.
in computer display we have even more colors because we have an alpha layer that adds an additional 8 bits for 32 bit color.

I hope understanding that from my perspective helps to remove some of the ambiguity.

Show me a monitor that has a ALPHA pin.

Your talking software conventions used for marketing and graphics programing and that doesn't fly here in a hardware discussion.

Steve

[keeperx]

im gonna go with pin 4.. (j/k)

[mixedgas]

im gonna go with pin 4.. (j/k)

There you go again, pin 4 on what standard?

Steve

[heroic]

Show me a monitor that has a ALPHA pin.

Actually DisplayLink has support for alpha channelization

[krazer]

So does component, s-video, etc but that has absolutely no bearing to this thread. We are trying to make a d/a converter for driving laser diodes. The only logical way to do this is to have one channel for each color, of which 8 bits is probably more than enough. One could argue that in some systems where you have the lasers unballanced (ie, a 1w green but only 100mw of red and blue to allow beam scanning and full color shows at the same time) you can loose a few bits of information in the dac, but thats beyond the point.

You can use irrevelent naming schemes (heck lets call it 'millions of colors' if you want to stick with your 'it perspective') but the point remains it is 8 bit rgb (or possible rgbv or robgv if you have that many wavelgths in your projector).

On that note, i think that if this dac is going to get anywhere you need to focus on what is needed, not what you could do for a few extra $. Eithernet? come on..

[heroic]

The only logical way to do this is to have one channel for each color, of which 8 bits is probably more than enough.

We need more than eight bits so that we can smooth out the kinky power/intensity response curve.

On that note, i think that if this dac is going to get anywhere you need to focus on what is needed, not what you could do for a few extra $. Eithernet? come on..

Ethernet is an easy add.

[cfavreau]

Enough of the 24 bit vs RGB vs who cares... really it is all a moot point really and not really for this thread.

12 bits per color channel would be great for having software correction for not so linear analog modulation.

Ethernet is nice. It isn't hard to work with and it is fairly easy to program for... and you can put power over it ... but I am not going there...

I would have to agree to a certain extent with Krazer as the first edition would be just what is needed to get it going and no more... over engineering has a way of helping projects fail because of too much complexity... especially since we are doing this as a hobby.

I would have to say though that since the Microchip DAC's are being used and they are 12 bit .. why not just have 5 or 6 of them.

And for Steve's comment about the sole source... we could get a chipset for the sound card DACs or even turn one of these USB micros into a sound card to form the basis for a budget DAC... .no one is restricted to a custom microcontroller.

So I think everything was figured out... so who is going to volunteer to do what?

I don't have a great amount of time however I am working on a Open API DLL and am in the frame of mind of API DLLs and such so I would like to volunteer myself for the PC interface side of things. I can help out on firmware too but I don't think I would be up to the task timewise to do so.

[keeperx]

There you go again, pin 4 on what standard?

Steve

it was a joke.. pin 4 on a standard 15 pin VGA cable is 'unused'

[cfavreau]

You just need to reply ... why the VGA standard of course