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Thread: one more laserist with you! ^_~

  1. #1
    Join Date
    Nov 2006
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    Default one more laserist with you! ^_~

    hi people!
    very very glad to see all of you!! :)
    im new on this forum, so in short ill write my story.. (sorry for bad language skills sometimes, im from russia ;)
    so, one day of this summer i surf on 'net and found this page... http://elm-chan.org/works/vlp/report_e.html
    at a first look i was very impressed for a practical evidence of possibilty building a scanners (that time im even
    dont know the words 'galvos' and 'scanners' - id like to call them just 'motors with mirrors' :D), so, as i said,
    it has a great impression on me, .. i learn a bit later more accurately this page, and noticed, that even with a
    great amount of time needed to spend for assembling the whole device.. its electronic part availible for building
    with my home availble tools and my skills... but the mechanical - i mean, galvos - is nearly unreacheble :)
    so, i began to realise what i need to make this device. ... first, of coarse, it was the laser. i looked at local
    electronic stores, but the best i found was a 5mw green device at a price ~ 50$ . so i bought it :)
    at this time i was nearly happy just to own a green laser :).... but a bit later i still want some more... ;)
    as usually, its always the need to get instant results :)))... so after reading some pages on open-loop systems
    and enumerating devices availible for me, i decided to use some dead HDD as open-loop galvos prototype...
    i build a amplifier on TDA7385, glue a mirror on a hdd positioning head, and plugged a output from my soundcard
    (actually, i have a standalone mixer ALTO-AMX100FX =), so i can adjust the output level)... to amplifier))..
    and amplifier output to a hdd head colis ... ), so at a one moment (maybe the time of aligning a laser...)))
    i was happy too ... seeing some sound synchronised lissagou like patterns :))))...... but later i still want some more ;)
    thou, my hands at that time, and lack of free time doesnt allow me to build galvos like elm-chan build.....
    so that was a wery first experience with lasers & galvos in my live =)
    later, i started to read all information i found on the net on galvos, lasers and lasershow .. so on,.....
    im began to realize things by little... at a fast considering, i found, that building a complete closed-loop system
    with galvos and amps by myself will take near 2-3 year of my life, of course it will bring the expirience... but also
    i need to get money for components :)... so i decided to take mechanical part seriously later, if there be enough
    amount of time ;). in spite of this, i began of searching a complete galvos+amps sets at affordable price....
    also, after searching of where i can buy a somewhat a powerful green dpss laser (>50mw), i was very depressed
    when i see prices somewhat likes ~500$ for a 50mw at local stores.....!(... later i found a dave/aijii ebay shop,
    but at that time i have no experience in buying something from foreing countries, and have a resident thought
    that [ebay = paypal = not /officially/ for russia] :). maybe a month or two i just look at this page (dave's shop),
    and realise how is would be to own a <100mw laser.....;) i often even have a dreams (or nightmares))) of it...)))))
    so...so oneday... i decided to go all forward, but to one result .. even it will be negative, decided give it a try and
    do all to make it true or just forget about it. in my surprise, at that time paypal enabled official registration for russian
    citisens, so this is the last, but not least, that pushes me to begin that process ))))
    at first, i was aimed on a 200mw green laser and a 15kpps set of scanners, i just decided it will be enough for all
    purposes at a some kind a long first time... but at my surprise, i win a 300mw laser at auction! ;), so i was again
    happy enough ... the whole items + postage price was < 1000$ ;). at that time, i just thinking that transferred
    money to /dev/null )))) in case of negative result in case not to worry (read: "ive done everything that i can,
    i send a ~1000$ for a making some unrealible dream to come true, it was just a try, anyway you would tear youself
    in case 'why im even not trying!''))))))))) so, again it was a surprise when UPS courier delivers the package right to
    my home...!) hehe, im still happy now.)
    dave, thanks for laser again! ;)
    OK. what i have now:
    5mw green dpss (with a potentiometer adjust, i think it can do ~8-15mw, but its overheated faster)
    300mw green dpss (GL532T-300 / LP532-300 model)
    15kpps scanner set + standalone board (as i read, scanner set can be rated at 12 or even 8kpps, but galvos can do up to 30kpps with another amps)

    ...two days after i received the package, i begin to figure out how to assemble the galvos set, and at least, just test it ;))))
    first, i realised, that some wires comes with galvos amps (especially the wire for +/-18v) is for an old type of power supply - but, i found one more 3-pin-female wire with one soldered end.. ;) i figure out immediadly the reason ;))).. and solder it to make a one. seems, thats an only needed 'solder part' to make this set to work ;) (also, i was try to find some datasheet before, but at a quick look at set its all figurable and considerable even for little lame users ;)))).... so i just plug in, and its worked well!) nothing seriously if you really want it to run now ;).

    also some words about so called 'DMX sound activated board':
    first, i began to write emails to dave (text is looked really stupid for me now)))))... but as usually, i just figured all by muself.
    1. the board is build on the SYNCMOS MCU, working at 40Mhz. (not bad!)
    2. onboard DAC is a dual, 8 bit resolution (dont remember...parallel i guess)
    3. MCU is genarating a TTL (mb PWM???) outputs on a R-G-B (but i dont think that someone will use it with RGB setup, thou))))))
    4. there some comparator on a opamps, two exit is here - first a signal (MIC), second - a comparator lever, i think (VR). as i notice, the MCU is somekind syncronising to this signal (do a start/stop of internal patterns) so when i run it a bit longer, after setting a correct level - seems that visual corellation to music is appears ;)

    ...when i played enough with that board, i need somthing more again :)...
    so, i decided to reprogram syncmos MCU at first ))))).... and later, (when found, that it would be hard to reprogram it, and in case without having a sources of current firmware) just get it off ))))))))) to use pins that go direct to 8bit DAC, and do an LPT interface....
    but later,,,
    later, i found a lumax.de .. and as im having some skills with AVR (especially ATmega8535 MCU units), i decided to build something simular to that device. for now, im intended to build a USB-DAC using FT245BM/R series USB-FIFO + ATmega8535 (16Mhz) + [AD7237A (dual, parallel 8+4 load, +/-5 v DAC) or AD7233 (serial, +/-5v ), or.. DAC8512 (serial, 0..4,095v) +OP295(to make 0..0,495 -> +/-5)]. for now i have almoust all componets (FTDI, AVR, R+C, DAC8515 + OP295), exclude of / and waiting for / AD723x DAC's + SRAM ;) - im even understand how to make a framebuffer for ~60-70kpps max speed on a 512kB SRAM . but for now i just want a fast enough point-based DAC ....
    ...now im in stage of making a USB-FIFO))))). 1st prototype was good. but not enough to make a pc detect it... so, after ~50hrs of life .. making a board for a LQFP-sized component (first expirience with making a board with a chloride-ferrum .. i dont really know how to express it) .. and then solder it to another board + components (quartz 6Mhz, resistors, capaciators .. + USB-B type connector)... and... after cheking soldering and shematics 8 or more times + testing it nearly ~8 hrs with oscilloscope... i just thtrow it away)))) (sad, but true.,))))))) i need a new development board and some of 6Mhz quarts if i intend to make again self LQFP base board for standalone ftdi.) . so now im going to use a ready DLP-245BM DIP module, as seems im not currently having enouth skills to solder LQFP-sized components....(but later will make a try again, its just a question of skill ;). [guessing im just killed an FTDI chip with overheating/or static/ or voltmeter beeper (when tested a short-circuits on a homemade board with soldered FTDI on it), and it will be the greatest pain in ass to solder out that chip)))) to solder and test another - easiest way - do it from scratch again,.. so i just throw the board out of window...(hm..maybe there were a lot of unused space on a DIP-development board...) but anyway, it was a great fly down, and my nerves is OK after that)))].. i just think, that i must concentrate mainly on the overall concept of USB-DAC, so it will be more useful in overall experience and final result ;).
    now i have a lack of spare time, i must do my part time job, ... &etc..etc... but i will resume to developing as soon as i can, (year....and will sleep well enough to make it correct ;)))))).
    thanks for reading this message!

    PS. ill post some photo when ill be at home...)

  2. #2
    Join Date
    Aug 2006
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    Welcome to the forum Redstorm.

    It looks like you have caught the laser bug.
    Well done at jumping in at the deep end too.

    Jim

  3. #3
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    Welcome Redstorm!

    Glad to hear that you've found us here. I hope you'll be able to complete the project you started. (I'm also glad to hear yet another story about the good service offered by Dave and aijii with their E-bay auctions!)

    If I understand your post correctly, you are attempting to build your own digital-to-analog converter (DAC) to connect your scanners to a computer. I'm wondering what software you plan to use to control it? Are you going to use one of the public domain programs, or did you plan on writing your own software?

    There are schematics posted here on this forum that will show you how to build a DAC that will plug in to a computer's parallel port (LPT port). From what you mentioned in your post, it sounds like you have more than enough knowledge to sucessfully assemble it. Here is the link to the discussion. It might not be quite as fast or precise as the USB DAC you were talking about towards the end of your post, but it would be a good starting point.

    Are you familiar with the Poplescan software? There are a few users here on PhotonLexicon that are using it; they may be able to help you get started. There are other software products that offer more features, but they also cost more. Depending on your budget, you might want to consider some of them as well.

    You sound like the sort of person that enjoys building things all by yourself, and that is great. But do you have the time to build your own DAC and also write your own software to run it? Or do you want to spend more time playing with that new 300 mw laser and the new galvos? It's something to think about...

    And, again, WELCOME to the forum. And don't worry about the language skills. We understand just fine!

    Adam

  4. #4
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    thanks for advice. i know it might sounds a bit strange, but i dont like an LPT port ;). so, i used it now to load firmware to my MCU, .. and have some expirience with communicating self-made devices over it. but i think, now its better to begin with usb, .. and, as my calculation follows, the LPT thruoutput isnt enough to drive dual DAC (+blanking) at a high speeds, so the scanrate will be slow. later, i think, i will want a better galvos ;) i think i must concentrate on a device firmware, the most interesting part ...;). and writing a driver for a some well known software. after that, maybe i write my own specific software with an opensource concept maybe even for linux. but now i need a example of working software with open driver interface (in case i need to write only driver myself to go, for example to draw ilda pattern) to test the USB-DAC on the development process and improve it on the fly,.. and to learn some key feautures this software should do.

  5. #5
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    Hi and welcome Redstorm!
    That's a nice presentation!

    I wish you a lot of pleasure here.

    Seb

  6. #6
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    Welcome aboard Redstorm, enjoy your stay!!

    Dave
    KVANT Australian projector sales
    https://www.facebook.com/kvantaus/

    Lasershowparts- Laser Parts at great prices
    https://www.facebook.com/lasershowparts/

  7. #7
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    Quote Originally Posted by redstorm
    thanks for advice. i know it might sounds a bit strange, but i dont like an LPT port
    Actually, that doesn't sound strange at all. There are some real problems with using the parallel port - especially if you are running the Windows operating system. The flow of data to the parallel port can be interrupted by many different system events, including mouse clicks, hard drive access, or even inserting a disc into the CD-rom drive. When the data flow is interrupted, the galvos will "freeze" in position. So, yeah - there are good reasons why some people don't like the parallel port.

    its better to begin with usb, .. and, as my calculation follows, the LPT thruoutput isnt enough to drive dual DAC (+blanking) at a high speeds,
    I agree that USB is a much better interface. And you can certainly push more data through the USB port than you can through the parallel port. I don't know if anyone has ever tried to run a pair of DAC's off a parallel port; I suspect that you are correct though - there probably isn't enough bandwith available.

    I do know that it is possible to run as many as 6 separate DACs (each controlling their own galvos) off a single USB port. One of the members here, Yaddatrance, designed and built his own controller board that was based around the SX52 microprocessor. It could control 6 separate sets of galvos all running different programs. Here is a link to the discussion about the board he designed.
    i think i must concentrate on a device firmware, the most interesting part .... and writing a driver for a some well known software. after that, maybe i write my own specific software with an opensource concept maybe even for linux.
    There are several software packages to choose from. Pangolin is widely acknowledged to be the industry leader, but it will only run on custom Pangolin hardware. The X-29 / Full-Auto software is also widely used, but again - it will only run on custom hardware. Mamba Black (and it's big brother, LDS) will run on a wide variety of hardware, using both the USB and parallel ports. In theory you should be able to write a driver for Mamba that will work with your DAC design. Then again, there are a few programs that are available for free (like Poplescan, for example) that might also work, assuming you could write the driver...

    As far as linux is concerned, you might want to have a look at the linux-laser site and the bilda software. To the best of my knowledge, this is the only linux laser show project that is designed to use a USB DAC. There are a few other linux lasershow projects out there (notably Laserboy and the uclinux project), but they are both designed to use a modified PCI sound card as a DAC. Still, you might find some interesting information on either of those two sites.
    now i need a example of working software with open driver interface (in case i need to write only driver myself to go, for example to draw ilda pattern) to test the USB-DAC on the development process and improve it on the fly,.. and to learn some key feautures this software should do.
    The linux-based bilda software is probably your best option if you need some open-source software to test your DAC design.

    However, if you are interested in designing your own software, you might want to go to the Medialas website and download the 1.63 update for Mamba Black. Although you do not have the USB dongle to enable all the features of the program, you will be able to load ilda files and display them on the screen in the preview window. You will be able to experiment with the interface (including all the effects) and see how laser shows are put together using the software. You can't save your work, and the software will not send any output to the DAC, but nevertheless - playing with the software might help guide you towards your own design.

    Best of luck to you! Keep us all informed as the poject continues!

    Adam

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