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[on:]

hey guys!

new to arduino here, actually just bought my official starter kit and am havin a blast already.  I am wanting to try to make one of these soon:



As far as I can tell you just need to strobe light at a specific rate.  What I am wondering is the following:

Do you think this could be achieved simply with one or more LEDs, an arduino, and maybe a pot to fine tune the strobe rate to perfection?  Or will I perhaps need to buy some pre-made strobe light type equipment?  Also totally off topic but I'm also open to hearing ideas on getting the water flow rate right and making a self contained, electrically powered, water flow system.  That is more mechanical though than anything I assume and can figure that out on my own/elsewhere.  But, I would love to hear what you think!

Thanks in advance!

-Leo

[Reply #1 on:]

I think you could also do this with analog circuitry as well. If you want to do this with Arduino, keep in mind you have to program the light to strobe synchronized with the actuation of the pump. This man explains it well in this video:

http://www.twittube.fr/video/OtxlQTmx1LE/strobe-light-makes-water-drops-fall-in-slow-motion/

Good luck with your project!!

[Reply #2 on:]

Yeah...  An Arduino would work to generate pulses to drive a strobe.  But, you really don't need an Arduino.   Something like a 555 chip can be used to build a variable pulse generator.

It's going to take more than one LED.  So, you'd need a MOSFET (or something) to boost the power of the Arduino (or 555).   The trick with a strobe is to light-up the action with the strobe (which takes plenty of light), and then have darkness (so you can't see the movement) between flashes.  The combination of a dark room and flashing lights means that something like this needs a special environment and is not practical for a "living room" decoration.

Or, you can just buy a strobe...   Even if I was going to build something, I'd probably buy one to experiment with first.

Here is an  LED strobe light, and here is a smaller one.  A traditional strobe (or flash) uses a Xenon flash tube.   These require a few-hundred volts and are a bit tricky to build.

It's fairly easy to make a spoked-wheel or a fan look-like its stopped or rotating backwards.   The water might be trickier...    The drops need to be evenly-spaced and approximately equal in size, so that the "next" drop appears to be the "previous" drop falling upwards.   For that, you'll just have to get a pump and some tubing, and experiment!

[Reply #3 on:]

I think you would need a mechanism that creates water droplets at a constant rate, or perhaps a number of selectable rates.
You then need a strobe light and by varying its frequency you will be able to make the movement of the droplets appear to change.
I think you would be better with a strobe light rather than LEDs. The strobe might have an external trigger and an Arduino could be used to provide the trigger if you wanted to change the strobe rate under program control.