Topic: LaserBoy tweaks.

[aceman500]

Hi James!

So here you are! I was looking for you on Photon Lexicon, did not realize they threw you out!  Im new to all this.
So my projector is almost done and I wanted your input. I want to start with an ILDA test pattern via laserboy to my soundcard DAC setup and here is what I got:
http://billyname.com/sandbox/ilda1.jpg
 (48Khz sample rate, default laserboy settings) Using 20K Scanpro galvos, correcting amps, 3 analog AOM's, yadda yadda..



The kind folk over at lexicon told me about the offsets, and I applied them (7) after this image was taken, and I noticed and improvement with the gaps. However I think its still needs work as you can see. Assuming my galvos are tuned - could you explain the other settings in the <tab> menu that would perhaps help. I am saying they are tuned because the pre-programed demos in the DMX board that came with it look crisp,  although the should include  an ILDA pattern as well.

I was also told to properly work with the ILDA test pattern I must get LaserBoy not to optimize and reduce the sample rate to 20Khz.. Could you go over this? Below are some more photos of my setup. And I started a thread over at lexicon < Advanced Technical Discussion : My first of A Million questions.>

BTW I really like the new add stereo wav to 6 channel wav.. Saves me from using an additional sound  card for music.

The people over there and very knowledgeable and kind. Many kudos.
http://billyname.com/sandbox/laserboy.jpg
http://billyname.com/sandbox/IMG_0223.jpg
http://billyname.com/sandbox/IMG_0230.jpg
http://billyname.com/sandbox/IMG_0231.jpg
http://billyname.com/sandbox/IMG_0243.jpg
http://billyname.com/sandbox/IMG_0254.jpg
http://billyname.com/sandbox/IMG_0269.jpg
http://billyname.com/sandbox/IMG_0270.jpg
http://billyname.com/sandbox/IMG_0271.jpg
http://billyname.com/sandbox/IMG_0276.jpg
http://billyname.com/sandbox/IMG_0279.jpg

That last one is my Co2 laser, I thought I would throw it in.

Thank you so much for your time!
Aceman

[James]

Howdy Acemen!

I saw your posts over there and I thought WOW!

Look how far this guy has gotten with LaserBoy without asking any questions or complaining about the interface!

Fantastic!

I also noticed that you've got ALSA-mixer open in your BASH console! That totally made my day!

Welcome to the LaserBoy forum!

I will describe what some of the factors do that effect wave generation in the next post to this thread:

http://akrobiz.com/laserboy/forum/index.php/topic,114.0.html

Please tell us what you are using in the way of electronics. I can see the breadboard. What design did you use? Did you modify it in any way? What sound card are you using?

AND.... AS ALWAYS... Please feel free to call me or give me your number so I can call you!

330-762-7137

James. 

PS The two factors that control the maximum velocity of your scanners are:

3 max optimized lit vector in points
4 max optimized blank vector in points

The 3D space that all of the vertices live in is made of 16-bit signed integers. It is 65536 points wide, high and deep. The numbers you enter here will be how many points, in any direction, the scanners can move per sample. If your sample rate is 48000 samples per second and you set these numbers to something that looks better on your scanners, you are finding a velocity that your scanners like.

This also pertains to your question about showing the ILDA Test Pattern. If you do NOT optimize the vector information, you can reduce the sample rate of the wave that gets generated and be able to show the frame accurately. Some sample rate conversion is better than others, but, if you stick to integer factors of the real DAC sample rate (48 or 96KHz) you will be fine.

48 / 2 = 24KHz
48 / 3 = 16KHz
48 / 4 = 12KHz

But remember with this test there is also scan angle. If you put a stacked stereo pot on your X and Y DAC outputs, you can control the scan size from full size all the way down to nothing but a dot!

[BlinkenLights]

Welcome... glad you made it here..

#1 turn OFF optimization (Menu U option F)
the ilda test pattern should NOT be optimized before outputting it..


James can you make a test pattern for this?

[James]

Life is a test pattern.

James. 

[aceman500]

Thank you for your quick reply guys.

 "Look how far this guy has gotten with LaserBoy without asking any questions or complaining about the interface!"

Oh!

So you want me to complain? Like abuse do you?
Ok here goes:

The lack of a GUI interface sucks.
The menu colors make me bug eyed. (lucky I stopped LSD years ago)
And the lack of documentation sucks..

Other than that, it serves my needs! - for now

flame off..

The electronics are basically the same as I saw on your page. I made the 10K zener bias resistor 1K for better stability, and my galvo amps require a differential signal , so I use one amp for the + signal and an inverted signal for the - signal on x and y. My AOMs need 0-1v. So it's basically the same.
My soundcard is a CMI8768 - 8 channel sound card.. BOY! what a fiasco that was getting it working with all channels in linux.. I basically had to install the new fedora 10 with the newest alsa stuff to get it working. It has bugs with the channels in earlier versions.

Ok I'm gunna play now.

Aceman

[James]

THAT'S MORE LIKE IT! 

WOW! That was a good laugh! 

I had great luck with the 8768 back in the day! I remember when it came out. I had been using the 8738, 6ch before that.

If you like PCI cards, VIA makes a very nice 8ch chip. It comes on the Chaintech AV-710 7.1, if you can still get one.

I'll have to get with you and compare notes. It's been a long time since LaserBoy was Linux only and I have to admit I have not done anything but verify that it still compiles and works there.

Maybe I should revitalize some of my Linux only code that plays the waves that LaserBoy makes. It can do the sample shift on-the-fly.

James. 

PS Where did you get your schemo? That current flow resister has always been 1K.

[BlinkenLights]

" so I use one amp for the + signal and an inverted signal for the - signal on x and y."

good idea.....

[James]

Maybe not!

Depends on what amp and how fast. Op-amps do not have the same characteristics in both inverting and non-inverting orientations.

Since you have it breadboarded, you should try it single ended. Ground the unused phase of your scanner inputs.

James. 

BTW That GUI you think LaserBoy is lacking will come up on your Linux console. If you build your kernel with frame buffer support, you can run it at the best resolution your video card / monitor can give you. It's FAST too!

[James]

I'm really excited about the fact that you are working with LaserBoy in Linux!

What is your history of computers and such?

Do you write code?

James. 

[aceman500]

I'm really excited about the fact that you are working with LaserBoy in Linux!

What is your history of computers and such?
Do you write code?

I started with a TRS-80 Color computer a LOOOOOOOOONG time ago I was like 11, and that was it..

 

Good question. I struggle with it. I know some c - some java.
Once upon a time I turned to a friend who is a big wig programmer for a large telcom.
(he dubbs himself "THE BEST OF THE BEST OF THE BEST") to teach me.
I could never get a straight answer to questions. Every time I would show him code he would tear it and me up over how sloppy it is. I tried to explain, I'm not intrested in a career in programming just want to do enough for shit like this.. and other projects I work on. And good enough means good enough for me.
BUT NO! Its gotta be perfect the first time. He expects it to be production quality. I would ask a question: how do i do this -  or whats the syntax of that.. Instead of answering,  he would go? Why do want to do that?  --- BECAUSE I WANT TO! NO you got to do it like this.. Only his way is the right way.
Another time, following an example in a book, I made the earth shattering mistake of using a goto in my C code.. Now the book , and I, know they are not the best thing, but in this case it made life easier.
He said OMG this is the worst code i ever seen. GOTO Weak tool of a lazy mind. Weak tool of a lazy mind!
Only bad programmers ever use goto..You are a terrible programmer. On and On..I still havent heard the end of it. I greped the linux kernel sources.. There is like 200 of them  . HE of course said they are all bad porogrammers.

So at any rate that whole thing made me sour to programming, and I have not really done any since.
Since I am obviously not a top notch programmer.

Ok that felt good to get that off my chest

So James I have some more ILDA test photos for you later and more questions...

[James]

Awesome!

I love code! I'm also ready to tell you that I am very good at it! But I believe that coding is a never ending learning experience and everyone has to start somewhere. I love to explain stuff to people and see the light go on in their head! Not everyone will get code.

You sound like you're about the same age as me and Dean.

Looking forward to the next pics!

James. 

[aceman500]

"I'm also ready to tell you that I am very good at it! "

So it's true! All programmers are arrogant! 

Im sure this guy im talking about would say your a bad programmer too..


"I love to explain stuff to people and see the light go on in their head!"

Well at least you explain and not show off.

"Not everyone will get code."

Oh I can - and do - get it. I just gotta do it. - not rely on others to help. and practice. Study, look at others sources.. etc.
Im just apprehensive to start something because of the fear now of doing something "wrong".

 I just made the mistake of thinking I could get help from someone knowledgable.

Making a "Full Fledged"  open source linux based laser show software (WITH A GUI INTERFACE!)  is tempting.. It's needed.  (Can you tell yet I have no love for Microsoft? ) Using the soundcard is soo cool and portable..
But proably over my abilities.. But I can look at your source! In all honestly I can tell you know what your doing. Your implementation.. well there always tomorrow..
I used to be a beta tester, and It was my job to see software was easy and intuitive to use as possible -  and bug free. How software should look, feel, act, crash is something I know a great deal about. So laserboys interface was kinda shocking to me when i first saw it. (IBM AT with EGA display?)
But im working through it. (its like fungus - it kinda grows on you and can never get rid of it.)

OK enough rambling today..

Now laserboy question:
I need your opinion
I turned off optimizations, and saved thees patterns at 22000Khz and 16000Khz respectively, and applied the delay.
(3 for 22k and 2 for 16K)
 

Notice the circled area.. The beam is not returning where it started.. And straight lines are slightly slanted.
Laser boy is not doing anything Im not aware of when optimizations are off right? Thees are like a virgin ILDA test patterns? I wonder what's causing this.






So I'm trying to nail down the cause of this anomaly. I would like to blame LaserBoy but I think its my amp board. The dam breadboards have crappy connections.. Galvos or amps..? dont think so.. I will but the DMX board back on to verify. I think getting this pattern good is important place to start.
I'll also look at the  signal on the oscilloscope more carefully.

Anyone else care to compare test patterns? (I''ll show you mine if you show me yours!)


Thanks for putting up with my ramblings..

[James]

"I'm also ready to tell you that I am very good at it! "

So it's true! All programmers are arrogant! 

Im sure this guy im talking about would say your a bad programmer too..

There's arrogance and then there is confidence from experience, knowledge and wisdom. 

Your stuff doesn't look too bad for not being totally tweaked up!

James. 

PS You should ask your friend what he thinks about the ILDA file format and its rich history of extension attempts.

[BlinkenLights]

what you see looks like scanner tuning.. damping issues.

are you sure your scanners are tuned?
what scanners do you have?

try outputting the wave at 20k or 30k instead of 48k

[aceman500]

what you see looks like scanner tuning.. damping issues.

are you sure your scanners are tuned?
what scanners do you have?

try outputting the wave at 20k or 30k instead of 48k

20K Scanpro scanners. (ebay)  I realize they are cheapo scanners - as scanners go. Perhaps this is the best they can do...
The first picture is at 20k (22k actually) and the next is 16k, better but still has problems.. (8 deg)

As far as tuning the scanners I want to rule out other things first. They are supposed to be pre-tuned. Each amp has a matching galvo. In addition there is absolutely no documentation on what the various adjustment pots do or how to do it.. I don't want to making things worse by randomly twiddling.  And there is lock-tight on them.

Ace