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Thread: DMX control of laser projector

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    Default DMX control of laser projector

    Does anyone have any resources on how the DMX connector and associated data transmission protocol is used to control a laser projector? I understand the ILDA DB-25 connector but have been asked to interface a laser harp to a device that has just the DMX connector. My research so far has not turned up anything specific to laser devices. Steve

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    Hi Shobley

    Laser projectors controlled by DMX have a circuit card with built in patterns. The DMX desk transmits packets of data consisting of a value from 0 - 127 to the projector so for instance to select a stored image, the Slider for say channel 1 is adjusted until the laser displays the desired image, then other sliders are adjusted to manipulate the image in various ways. As you move a slider, the data for that adjustment is transmitted as a package of data.

    I hope this is the sort of explanation you were looking for.

    Carl

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    Yes it does, thanks for that. I struggled to see how you gained precise control over the laser image with the DMX port.

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    Hi Steve

    Sorry, quick thread hijack....

    Did you ever publish the schematics for the laser harp with Wii controller? Please PM me

    Cheers

    Jem
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    Quote Originally Posted by shobley View Post
    Does anyone have any resources on how the DMX connector and associated data transmission protocol is used to control a laser projector? I understand the ILDA DB-25 connector but have been asked to interface a laser harp to a device that has just the DMX connector. My research so far has not turned up anything specific to laser devices. Steve

    http://www.laserfx.com/Backstage.Las...s/ISP-DMX.html
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    Quote Originally Posted by Carl B View Post
    The DMX desk transmits packets of data consisting of a value from 0 - 127 to the projector so for instance to select a stored image,
    That must be MIDI, DMX sends values from 0 - 255.

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    Steve

    If you want DIRECT DMX control of the laser scanner You would need a circuit that translates the 0-255 values into voltages to control the x y and intensity of the beam. For example you can have DMX Channel 1 to control the x position, channel 2 to control the Y position and channel 3 to control the intensity. Based on the rate of DMX transmission I doubt you can control the x,y positions to generate any sort of graphics by sending DMX values (for channels 1 and 2 in our example) fast enough

    I plan on using the FB3 to store ques (graphics or set of x,y positions) and use its ability to ready a DMX channel to display a cue. So If you have all the desired laser cues in the FB3 you can display then under DMX control with the FB3. The FB3 will also allow DMX control of size, rotation etc on the laser cue using other DMX channels
    Gil V.

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    Quote Originally Posted by gilv_58 View Post
    If you want DIRECT DMX control of the laser scanner You would need a circuit that translates the 0-255 values into voltages to control the x y and intensity of the beam. For example you can have DMX Channel 1 to control the x position, channel 2 to control the Y position and channel 3 to control the intensity. Based on the rate of DMX transmission I doubt you can control the x,y positions to generate any sort of graphics by sending DMX values (for channels 1 and 2 in our example) fast enough
    44hz in theory, way less on many controllers in practice.

    Big "NO!".

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    If you want to interface it to your laser harp, all you would need is size control on x(I think), and intensity. You could shrink the harp, and control the laser through DMX.

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    Quote Originally Posted by -bart- View Post
    That must be MIDI, DMX sends values from 0 - 255.
    I stand corrected but I was still refering to DMX, I just got mixed up with the values scale.

    Carl

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