Laser Projector (Red, Green, Purple) "Laser 3D Party Light" from Spencer's

[mixedgas]

James, this is NOT a good thread to have your usual debate about minor things you cannot hear in sampling audio and that WAV files are better for driving galvos. It does not matter about time continuous waves vs points, as long as the Dac or waveform update rate is about 3x faster then the small ballistic step size of the galvo in its current state of motion.

Cambridge Type Galvo:

http://www.google.com/patents/US5844673

A Galvo is a "Limited Rotation Motor"

www.google.com/patents/US4135119

The above shows a cross section of a real old design. New ones have sculpted stators and rotors, and very small air gaps.

They come with either optical, capacitive, back-emf, or no position sensing.

Older ones or open loop units have torsion bars to return the mirror to center and to aid in damping.

Modern ones do not have torsion bars, and the damping/centering is provided by the feedback system.

Steve

[mixedgas]

Quote: Yeah, it was flickering horribly, but it was so slow that I could actually count the number of times the text "12K/30K" was being drawn. I assumed that it's drawn once per frame, so if I know how many points there are in a frame, then I figured that'd let me compute PPS. Maybe that's not a valid assumption.
End Quote.


Yikes, if they are so slow that the 12/30K is flickering that much, I'll apologize for that comment. Take 10 flicker times and average and your probably there, minus the human reaction time, say 100 mS for each start/stop.

But for the bang for the buck is quite good for a whole system. Plus you can experiment and learn without worry. Considering the cheapest controller I can get with SD card playback is ~180$ and shipping, this is a deal for a hobby starter set. Once in a while I just need something to loop a simple set of images for trade shows etc. Those gigs, while rare, do not justify hauling out a laptop or desktop.

I'm thinking of ripping the controller out of one of these. That is why I am so curious as to its bit depth and controls. 8 bit XY is not so useful these days, 10 bits is decent for some uses. Typical is 12 or 16 on a better controller.

Steve

[james]

James, this is NOT a good thread to have your usual debate about minor things .............

Huh?

Back down Steve.

Just another point of view.

James.

[DogP]

Yikes, if they are so slow that the 12/30K is flickering that much, I'll apologize for that comment. Take 10 flicker times and average and your probably there, minus the human reaction time, say 100 mS for each start/stop.

I purposefully slowed it way down by setting the speed to 5 to see the difference in quality vs. speed, and then wondered what the actual frame rate was (I counted 100 frames in 38 seconds and divided to get about 2.6 frames/sec). Most animations run at a speed of 10-20 (which I'm guessing means nothing without knowing how many points are in each animation). The images I took of the test pattern were at speed 15 (and I'll determine the scan angles when I get home and look at it again).

DogP

[mixedgas]

If I can find the install files, you'll get a freeware viewer in the morning that runs under windows, and tells you point count and ILDA file format.

Steve

[neutrino]

If I can find the install files, you'll get a freeware viewer in the morning that runs under windows, and tells you point count and ILDA file format.

Steve

Hey Steve,

Any chance of a copy of that freeware viewer too please?

Cheers
Rich

[DogP]

Okay... I just checked the scan angles (using this page as a reference: http://www.pangolin.com/userhelp/scanangles.htm ).

The maximum is 25 degrees, which is the first test image I posted. The second image is at 8 degrees, and the third image is at 3 degrees. All at speed 15 (whatever that means).

DogP

[james]

What? free software that reads ILDA and runs in Windows? Really !!! ?

And it counts points too !!!

[mixedgas]

Hey DOG-P

All the files you sent me from the SD card were ILDA type 0, the oldest format.
Most were freeware from around the net, one geometric frameset was ripped from a demo show included with a major laser show package.
One was a frame set I personally posted to the net as freeware, long ago.

You'd need ILD-SOS from Dr. Lava or Laserboy (A mouseless DOS like lasertoy that does neat stuff) to convert to this format.

I have source code/compiled programs that takes a ASCII file and rips it to ILD O. I'll get that on the way to you.
I have another one that rips ILD zed to ascii files.

ILD 0 is not used so much any more, because of more sophisticated color palettes in the other file structures.


Here is a link to ZILDA:

http://code.google.com/p/zilda/downl...ILDA%200.1.zip


Here is Guido's file viewer, from www.ilda.de I'll get you another one on Monday.


Steve

[DogP]

Thanks for those links, I'll check them out tonight. If I wanted to make the ILDA test pattern with fewer points, what does that take? Any software out there that will generate the pattern with an arbitrary number of points?

Most were freeware from around the net, one geometric frameset was ripped from a demo show included with a major laser show package.
One was a frame set I personally posted to the net as freeware, long ago.

Heh, I figured they were probably ripped off from somewhere... I'm guessing making cool animations takes time and effort, neither of which they're gonna do if they can grab it from somewhere else.

DogP