Originally Posted by
Buffo
You're correct, you don't need it.
DMX is a signaling protocol that is widely used in theater lighting. It can also be used to control various effects in a projector. For example, if you have a GM-20 actuator that will send the beam off to a lumina wheel, or a diffraction grating, or something like that. But if you're building a standard projector with just a set of galvos, then you don't need DMX.
Stuka was thinking about building a hybrid projector that could do scanned graphics and also have some diffraction grating effects built-in, so he thought he might want the DMX ability. While that would be very cool, I've only ever seen one other projector that had both features like that in a single case. Cool, but also complex...
Adam