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Thread: Hello everyone.

  1. #1

    Default Hello everyone.

    New here and thougt I'd introduce myself.

    I'm from sweden and have been intrested in lasers since I was just a little boy. Tried to build something laserlike with leds and an old projector when I was about ten. Now when I'm somewhat older and have some more cash I'm able to play some more.

    I've just got my first real system working. 2 x Microamp and TerraScans. They runs great but I'll have to work on the DAC part as I just made a quick n dirty DAC with parts I had at home. 8 bit and now double buffer. Running a homebrew software I've been able to do some graphics.

    Spelling Isn't my stong point, not even in my nativ language.

    Bt.w Is it normal that Microamps get really hot?
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

  2. #2

    Default

    Welcome to the forums!

    I asked the same question about the Medialas Microamps. Medialas told me that it has thermal protection that will kick in when it gets way too hot. Which is strange as ive never seen a temperature probe on the item.

    I still added a fan anyways. 125-135 F seemed a bit excessive

    Yadda states that the things are supposed to stay cool when tuned properly however even on an extremely low power setting they manage to get quite hot. I imagine it has something to do with the extremely cheap components they use.

    I almost cried when I saw the Microamps... There was about $15 dollars in parts there, quite sad when looking at the $600 price tag.

    Hey man, Post some pictures of your scan set! Id love to see them!

  3. #3

    Default

    As soon as I get a better camera I'll post some more pictures but until then here are some teasers







    The sega logo where running @ about 20Kpps. My software are very cpu dependent and at that speed it drift up and down about 500pps.
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

  4. #4
    Join Date
    Jan 2005
    Location
    Norway
    Posts
    1,301

    Default

    welcome here

    Sweden, finally one more from Europe 8)


    What software is you using ?
    Have you tryed popelscan?


    I got some scanners from jm-laser running at 8kpps i guess..
    But is soon upgrading to some D-40 galvo soon i hope (spec?)

    And I got a 240mW green dpss, and maybe in the summer there will be some blue one

  5. #5

    Default

    I'm running a homebrewed software. I've tried all software I could get my hands om but still havn't found one I like.

    Right now I'm working on the hardware and run it on my own show software. But I'm looking for a good editor. I've found some but the pricetag is scarrier than Jason, Freddy and Pinhead put togheter.

    I might make a image to ilda converter using neural networks some day. So much to do, so little time.
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

  6. #6
    Join Date
    Jan 2005
    Location
    Norway
    Posts
    1,301

    Default

    i want pangolin software ......

    So that`s why I just use popelscan that is totally free
    and it`s the ONLY one i can manage to find that is free !?


    Where in sweden do you stay ?

  7. #7

    Default

    Just checked your site out, Thanks for the link to PL!

    As soon as I get a content side of PL that works correctly I will link back to ya.

    Your dac. Wow. thats got to be one of the most amazingly compact dac's ive ever seen! good work! Seriously!

    Hows the linearity of display with that dac? Cant tell much from the SEGA picture.

  8. #8

    Default

    The "quick n dirty" DAC updates X first and then Y. This is of couse a bad thing. Linearity is better than expected. I wouldn't recomend anyone to use anything like this. I'm working on some improvments but that will take some time. An USB driven DAC with onboard CPU. I'm hoping to get it to run at 16 bit and something like 50 Kpps.

    Right now I'm testing a 89C450 from maxim for those that are into that sort of thing. But I think it's to slow.


    liteglow: I'm based about 4 miles north of Helsingborg. In other words, southern sweden.
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

  9. #9
    Join Date
    Jun 2005
    Location
    SoCal
    Posts
    490

    Default

    Nice! That's great work!

    When we built our 8-bit dac's we bit-banged it through the parallel port as well.
    You should be able to see 40kpps (with full 8-bit X, Y and 8 ttl channels)
    though a standard modern PC parallel port with bit-banging... With ECP/EPP
    you can go very fast, especially on systems using the SuperIO chips...



    I noticed you don't have color/blanking modulation... We used an octal
    latch 74HCT573 (or 74HCT373 if you're masochistic) on our old 8-bit board
    to store the states. An alternative idea is that I noticed that you're using
    the 7226... If you use the AD7228, you can split the octal dac on it into
    2 for XY and up to 6 for analog color modulation... The AD series have
    very annoying timing requirements which is why most folks prefer the
    National 0830 and 0832 dacs which are surprisingly fast. Plus the
    double buffer on the 0830/2 line means you can have a very clean timing
    diagram with simultaneous updates on both X and Y which can be
    important if you're planning on running very slowly (for example, if you're
    using your board to do an anno bleach)

    A standard PC parallel port uses 1us to write per byte... so at your
    specified 6 write cycles, (I'm going to assume that you do DATA byte
    + CONTROL byte per cycle) it will take 12 microseconds to output
    per XY output.

    This means that at 30kpps, you have a spare 12us to fetch the next
    point to send to the scanheads... if you're maxxing out at 20kpps,
    then I'd look at optimizing the code. A 1Ghz CPU can massage the
    ILDA frame data and performing 2 sets of 3D transforms (one for
    orientation, the second for geometric correction) in 5 microseconds
    leaving 7 microseconds for timing jitter correction.

    A very neat trick is to use a 74HCT138 to handle your timing diagram...
    If you use grey code (look it up if you are unfamiliar) to address the chip,
    you can have very crisp timing outputs with low overhead.



    We did that modification to the 8-bit board above before we made our 16-bit
    one and it helped everything immensely.

  10. #10
    Join Date
    Jun 2005
    Location
    SoCal
    Posts
    490

    Default

    Oh yeah! I forgot to mention... Perfecting the states while off the parallel
    port is invaluable when trying to run of the microcontroller when you go USB...
    We developed our 16-bit board in stages so we could test each section
    independantly...



    The 16-bit board is on the right, and can be linked to the microcontroller
    or the parallel port for testing.

    The differential line drivers were also tested independantly on the bottom...
    Conclusion? Actual opamps suck less than dedicated line drivers, though
    the SSM2142 comes closest to being useful.

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