Modifying a "Cheap Chinese" Red-Green starfield laser to allow for motor control

[Zeph]

Regarding sky leakage and planes, how much power is there in one "sparkle"? (How many dots is the power divided among?)

[Zeph]

Thanks for the write-up! It's very well explained.
(Tho I do wonder if you make a habit of opening dangerous devices atop the obit pages, just to remind yourself to be careful)

This mod is about on/off control of the effect rotation motor.

I don't have a unit, but it sounds as if the laser can be turned on/off via sound (but isn't very sensitive to the mic). So I'm thinking of two further mods:
External control of each laser (on/off - tho proportional would be really cool it may not be possible).
External control of the motor speed (apparently there is a manual control for this so the motor is variable speed)

I picture three Vixen channels which can at the minimum turn the lasers on/off and the motor on/off; and possibly the second could control the motor speed - in sync with the music and other lights.

And then I picture two or more of these pointed into the trees from different angles, independently controlled...

About the cheapest I find (including shipping) in a quick search is two for $47.50 shipped (I do not vouch for it). There are others on Amazon for just a few bucks more.

http://www.amazon.com/Green-Laser-St...2746946&sr=8-1

[Zeph]

OK, now I'm expanding that vision to a multi-pattern laser like:

http://www.ebay.com/itm/13in1-Green-...ht_4258wt_1163

I'd like to see what's inside this. The video makes it look like there might be a wheel with various effects around it (speculation). So I wind up wondering about using a modified servo if so, to select the effect as well as control the movement. So for those who own such lasers already, what does the motor turn?

Does anybody have one of the multi-pattern lasers?

[tfischer]

External control of each laser (on/off - tho proportional would be really cool it may not be possible).
External control of the motor speed (apparently there is a manual control for this so the motor is variable speed)

I was going to put the entire unit on a control channel to determine when it's on or off. I suppose you could split the two colors (red and green) into independent control, but I'm not sure it's worth it - the red is considerably dimmer than the green (unfortunately red is all I have left now, lol)

For motor speed, I'm sure some of the gurus here could hack it, but that's above me. There's a simple knob to control it manually. I suspect that's just a trim pot or something... if someone knew how to make that controllable, you could change the speed. Again, I'm not sure the results are worth it (the effect is kinda the same regardless of the speed) but it might be a fun experiment.

-Tim

[David_AVD]

I have a couple of those units and made a DMX PCB to control the red and green lasers separately as well as run the motor forward / reverse at variable speed. It can also switch the overall laser unit on/off. While I did make the board late last year, I ran out of time to do the firmware. I hope to get that done in the next couple of months.

[dirknerkle]

How well do those things really show outdoors? In some of the videos, it appears that they've set the unit on a table about 5 feet away from a white wall and turned out the lights -- I'm having trouble visualizing how those tiny dots would even been visible from the road, say 75-100 feet away.

[David_AVD]

Being lasers sources, the distance doesn't change the brightness as much as you'd think. What does change if the covered area. The results will be better with less ambient light of course, but they are still quite visible in a typical display.

[ukewarrior]

David,
Since you seem to have figured out the various connection and control points within the unit, can you post that information?
thanks

I have a couple of those units and made a DMX PCB to control the red and green lasers separately as well as run the motor forward / reverse at variable speed. It can also switch the overall laser unit on/off. While I did make the board late last year, I ran out of time to do the firmware. I hope to get that done in the next couple of months.

[David_AVD]

I will be documenting it in due course - once I dig out the laser unit and PCB from my pile of projects!

[Zeph]

David - Not surprisingly, you are way ahead of me!

I'm very interested (and apparently not alone). When you do that, could you add a note to this thread (or make the new thread now and I'll subscribe). I don't want to miss the thread in which you document it (but I can't subscribe until it exists!).

Thanks!