Topic: Soundcard DAC for Linux - buy a prebuilt one?

[Lydia]

Hey all, we just got a laser, this model: http://www.chinesedepartmentstore.com.cn/osc/product_info.php/products_id/1700

Which has 15K motors, *not* 30K motors, but that's beside the point.

I've been doing a lot of reading about the how to get the ILDA interface working with a Linux box and the soundcard DAC really seems to be the way to go when it comes to working with a Unix box (plus it's cheap!). Admittedly I have not done all the research I can do, I still have lots of reading to do but we are *really* eager to jump right in. Now I'm not nearly as good with a soldering iron as I am with a *nix machine, and most of the tutorials I've seen are very electrical engineer oriented, and quite likely a bit much for my skill level, likely leading to a brick or poorly functioning DAC.

So my question, is there a place (or a person) from which I can purchase a prebuilt soundcard DAC?

If not are there some instructions around that are a bit more forgiving for us more software oriented people?

Lastly, I've seen mention of an IRC channel hiding somewhere, is that still running? I'd love to get in there and maybe ask a few questions and learn from the general discussion that goes on there.

Thanks all! I can't wait to start playing with this all and (eventually) writing some fun code!

[James]

Hi Lydia!

And welcome to The LaserBoy Forum!

If you are interested in using Linux for laser projection, then you have certainly come to the right place!

Have you gotten LaserBoy and compiled it for Linux?

I can build a LaserBoy DAC for you for $200. I only have a few of those little printed circuit boards left, so please let me know. It might take a little time to get one together, but I will put your name on it and not charge you anything until it is ready to ship.

Like this one:
http://laserboy.org/forum/index.php?topic=378.msg5058#msg5058

I would also be glad to help you understand any part of the technology I offer.

James. 

[Lydia]

Hi James! Thanks for the welcome!


I certainly do have LaserBoy built and running, the software is the easy part for me


I would *LOVE* to buy one of your DACs! It really looks nice and I love that you sign the box, clearly you have confidence in your work

How long do you think it will take for you to build one? We are *really* eager to get started, but I'm sure you've got enough of your own work to do.

Oh! I do have a question for you, our device has both an In and an Out for the ILDA interface, I'm *guessing* that this means I can chain together two or more devices. In this case both lasers would display the same animation, or would there be a way to display a different animation on each laser?

Thanks James!

[James]

Hi Lydia!

You are probably correct about the 25 pin in and out ports, but you might want to verify that either by looking at the wiring or checking it with a meter.

If it is a simple pass through, then yes you can chain two of them together. As long as the projectors have fairly high impedance inputs, then you can chain more. But you need to know how much total current you are drawing from your power supply. If that is USB +5VDC, then you have a serious limit!

The only limitations to using two or more LaserBoy DACs is in the interface to the PC. If you run a box with PCI slots, and you use a modified PCI sound card, you can have more than one. So far, I don't think it is possible for two C-Media USB devices to work together.

How do you like getting around in LaserBoy?

What kinds of things do you do with it?

What is your experience with programming, Linux, etc... ?

James. 

[James]

If you look inside the projector, you might find that the inputs to your scanners are differential. That is to say that they have a ground, a non-inverting input and an inverting input. The LaserBoy DAC is NOT differential! It is only one ground for everything and one signal for every channel of control voltage. So, if you find the differential inputs to your scanner amps, it is possible to connect the signals comming from the ILDA port's pins 1 & 2 to either the non-inverting or the inverting inputs (and grounding the otherwise unused phase of the input). This will flip and mirror the projected image. If you run two projectors, you might want to make them mirrors of each other and spread the images side-by-side.

[Lydia]

First off: Sorry for the delay! Google did not like my mail server (functioning only as a relay) relaying email from your domain, I have changed my email address to go directly to my gmail account now so I should get notified properly

WOW! Thanks for the info, that's quite a bit more detail than I had expected, I will have to take a multimeter to our laser to figure out exactly how it is built. Thanks again for the great detail, You answered my question precisely and inverting the output is an *awesome* idea that we may have to tinker with.

We have not played with Laserboy too much as of yet, without a DAC we are not sure what our laser can really handle so we have not invested a whole lot of time into it, instead we've programmed the DMX controllable settings, which were far more useful than I thought they'd be. Once we get our hands on a DAC we'll start programming logos and animations for our use as well as learn how to use it in a performance oriented way. Laserboy does not seem to be designed for performances, but rather for creating and producing animations (which is very useful!), or perhaps there is a mode to use it in that would provide that functionality? All of the performance oriented laser control software I've found seems to be for windows

Do you have a time line for when you might build a DAC for us to buy? we have some shows coming up where we probably won't be doing anything fancy with lasers, but we'd like to get the DAC into our hands so we can start learning to use it and incorporate it into a future show.

Ah I have close to 15 years of Linux experience these days, at my day job my primary responsibility is SAN and Unix (AIX/Linux) systems administration. As a sysadmin I mostly write glue code, python having become one of my favorite languages these days, with good old shell scripting being a big part of what I do, and of course, perl. I have not written much C code since my college days, so I'm quite a bit rusty. In my off time Genetic Algorithms are a hobby of mine and I have a project that will be released once I find time to finish the webpage, I'll let you know when it's up

Thanks again James!
-Lydia

[Lydia]

James,

We picked up an EasyLase 2 box and have just started playing with it!

I have one question, I have not been able to find any documentation on Laserboy, is there any sort of info on how to create new animations and such? or will I have to figure it all out via trail and error?

Thanks!
-Lydia

[BlinkenLights]

trial and error.. its an undocumented software. BUT james is always very happy to help teach via phone, skype or here..

[James]

Yes! Hello again Lydia!

I am working with a guy on Skype now who has a lot of experience making howto videos.

But I always love to show it to people first hand! Please feel free to contact me via Skype at james_laserboy and you can share your portion of the screen that has your LaserBoy window in it. Then I can tell you what keys to hit to make all kinds of original art!

James.