Yes ... the bitmap is in ROM. Nobody but you has said anything about real-time video.

This is 8052.com and Chico has indicated that's what he's using.

I've not said the "design issues" you mention are "gone" but I do maintain that they are, at this stage, totally irrelevant.

There are lots of things that can be done with other equipment, but Chico wants to do something with what he's already got. He wants to project an image onto the wall. He hasn't said he wants to project full-color real-time video.

Further, you're mixing technologies, for some reason. On one hand you say that you can't do fills, which, from where I sit, you certainly can, and easily at that, and then you say you can draw a line at 20 kHz. I have my doubts about that, but maybe ... However, if you can draw a line, no matter the rate, what difference does it make whether the beam is on or off? It is only aimed at a given x,y locus for a small time. I perceive that you believe that you can draw only a few lines frequently enough to accommodate the persistence of the human retina. That certainly won't allow for movment of complex shapes. Simple shapes would be represented by a small and simple bitmap, for a monochrome raster display. Such a display could easily be updated from time to time if it were necessary or desirable to do so.

The only reason I'm taking the stance that the bitmapped/rasterized display is easier is because it requires only one degree of freedom for a voice-coil-driven mirror. The rest is just electronics. As always, there are many ways to "skin a cat," but in this case, it would be a good thing to start with something that Chico can actually build. I doubt he has access to high-precision machinery. Moving two mirrors requires not only that he build and precisely control a two-axis system, but that his construction be precise, say, to 0.01mm. Now I know how to build, "from scratch", precision bases and moving fixtures upon them, having done so for many years when necessary. I don't know that Chico has that experience.

Why not wait for Chico to tell us what he can do, and, perhaps, what he really wants to do.

Above all, let's not get off into bigger processors and more complex systems. AFAIK, all he wants is to project an image onto his room wall. If he has higher goals, let him say so.

BTW, I have no interest in this matter at all, aside from letting Chico do what he wants. I find the fixed-axis, spinning mirror approach inherently simple and easy to derive from raster scan circuitry that's been widely published. The rasterized display produces a line, as does a stroked display. Yes, coarse resolution makes the lines "jaggy" as you put it, but any other display projector that uses mechanical means is often quite non-linear as well.

Do you know what sort of laser Chico has? Do you know what sort of voice-coil and driver he has available? Do you know anything about his projection target? Do you know what images he wants to project? I dont! Let's let him tell us. Then we can make reasonable suggestions.

In the meantime, he's seen that there are at least two approaches that have already been fully developed. The choice between them should be his.

RE