Simple projector project on a budget

[Grix]

He's been doing some research and thinks he can do it cheaper with spinning mirrors instead of galvos.

Comments?

How can he display text with spinning mirrors?

[HankLloydRight]

How can he display text with spinning mirrors?

I believe with spinning mirrors you can get the same scanning effect as galvos.

Or maybe produce a raster image instead of vector. I'm not sure what he found.

[swamidog]

I believe with spinning mirrors you can get the same scanning effect as galvos.

Or maybe produce a raster image instead of vector. I'm not sure what he found.

you can do simple rasters with spinning mirrors.

[HankLloydRight]

Here's the spinning mirror laser projector:

https://www.youtube.com/watch?v=vvbzIy2U1J0

And build details: http://portablelaserprojector.blogspot.com/

It's interesting, to say the least.

[james]

So he wants to keep it on a real budget, and says he can build his own DAC with a pic microcontroller.

Assuming he can do that (I believe he can), is there any free (or almost free) software available to do basic letters and numbers?

You can also build a very capable DAC using an 8 channel USB sound device and a correction amp kit.

LaserBoy is free and it can be used to make frames of text and numbers. Once you have what you want it takes a fraction of a second to generate a wave file that, when played on the USB sound card, produces the signals that control the laser projector.

It's not exactly real-time but with some practice, it's close.

http://laserboy.org/forum/index.php?topic=561

LaserBoy and the modified USB sound device also work with a Raspberry Pi!

This is about as inexpensive and DYI as it gets!

James.

[HankLloydRight]

His latest out-of-the-box idea is to get 28 laser pointers with a grating on the end to project a short line.

Then arrange them in 4 sets of 7-segment numbers (like old LED displays). Then just selectively turn on and off each segment to display two scores.

I already told him that alignment is going to be hard, and of course, it would only work at one fixed distance, and if the distance changed, so would the alignment of each segment.

But this he can do for less than $100!

[dkumpula]

In addition, finding the right gratings might be a challenge. That said, this approach could be done within the $100 budget!

[polishedball]

If over 5mw, I assume this is for some sort of public thing, being a scoreboard. How is this device for under $100 going to be compliant or is it in use where it isn't public and nothing is sold in the same venue?

Pretty awesome solution though!

[HankLloydRight]

I can't answer that.

[HankLloydRight]

Well, he isn't wasting any time, that's for sure!

He says:

Presenting the number 4 in Seven Segment Laser Display
Crude initial proof of concept.
Using four 75 cent laser modules and pieces of 3/8" acrylic rod as line forming lenses.
I have ordered real line forming lenses.
Looking for 30 reasonably prices green lasers.
Working on a PIC microcontroller circuit to turn.