Ultrasonic Levitator not working

[Smsorensen]

Help! I’ve tried and tried and can’t get it to work. What’s wrong?


Moderator note: https://www.sciencebuddies.org/science- ... -levitator

[bfinio]

Hi - can you give more detail than "it's not working"? Are you having trouble getting a small piece of foam to levitate perfectly? Or as far as you can tell, are the ultrasonic transmitters not working at all? You can test to see if they're working at all by simply placing a piece of foam on top of a single transmitter. It should jitter around and bounce off.

From what I can see in the diagram, your wiring looks correct. One minor suggestion - if you have a red jumper wire available (or any other color besides black), use it for the 5V connection for the Arduino. Black is typically used for ground, so at first I thought you had your GND wire plugged into the wrong bus (+ instead of -).

[Smsorensen]

Hi, yes I can. As far as I can tell it's not working at all, I've set up every variation provided and still no luck. Yep I have additional wiring I can swap out the black piece for. I've double check everything and used the code provided for the arduino, I've also ensured I'm using one T and one R transmitter. Could it be a faulty breadboard? I might disassemble and try a simple test to see if it's the board

[bfinio]

Hi - you should be using two transmitters (T), not one transmitter and one receiver. But again, to make sure the transmitter is generating a signal at all, I would place a single piece of foam on top of the transmitter, and see if it bounces around. Can you try that and let me know if anything happens?

It is very unlikely that the breadboard itself is the problem, especially if it is brand new. Usually when projects like this don't work, it's because a single wire is in the wrong breadboard row somewhere. It can help to have another person carefully double check your wiring, since sometimes it can be hard to spot your own mistakes, and it's easier to see everything in person than it is for me to see it with the pictures, since the wires block some of the view.

[Smsorensen]

Thanks, I've ran another program just to light up a lightbulb and it worked with the same breadboard so I'm not sure it's the problem. I've switched to an adaptor for the power source as suggested in the tutorial. I can no actually hear the transmitters releasing a humming sound but still get no vibration of the small piece or paper or levitation.

[bfinio]

Can you post pictures of your transmitter with the small piece of paper you're trying to levitate? I got this project to work with small pieces of packing foam (just a millimeter or two in diameter) but did not test it with paper. I cannot guarantee that it will work with paper.

[Smsorensen]

I’ve included some pictures. The small piece of paper is green and I did find a small piece of white foam to test also and got nothing.

[bfinio]

Ok - I'm still seeing the 9V battery in your most recent pictures, can you post more pictures showing how you have the adapter connected as a power source?

[Smsorensen]

Sorry I had a bunch of stuff on the counter where I was working. I’ll include a picture

[bfinio]

Ok - from what I can see in this picture, your wiring is correct. To clarify:

1. You are using transmitters and not receivers, correct?
2. You do not see ANY movement at all of either the paper or foam if you place them on top of one transmitter?

[Smsorensen]

1. Correct I'm using 2 transmitters

2. There is no movement when I test on either transmitter although I can hear a humming sound coming from them now

[bfinio]

Hi - as far as I can tell from your pictures, your wiring is correct. My only remaining guess is the physical object you're trying to levitate may be causing problems. If you look closely at my videos for the project, you'll see that the piece of foam (which I broke off from a larger piece of packing foam) has a pretty smooth surface. Looking closely at your picture, it looks like your foam has gaps and is much more porous, which might mean that it's absorbing or letting the ultrasonic sound pass through, so the levitation effect is not working. Similarly, for the paper, I think I was able to get tiny specks of paper to jump around when putting them on a single transmitter, but it did not work if I tried crumpling the paper up. I could not get paper to levitate at all. So,

1) Can you try putting some VERY small, flat pieces of paper on top of a transmitter, to see if they bounce around at all? Do not crumple them up first.
2) Do you have access to any other type of foam or other very lightweight materials you could test, ideally with a smoother surface?

[Smsorensen]

We got a small piece of styrofoam to move but still no levitation and to make things even better my Arduino board will no longer connect to the computer…..

[bfinio]

Ok - if you got the styrofoam to at least move, that confirms that your transmitters are working.

Sometimes there can be USB communication issues that prevent the Arduino from connecting to the computer, but this is usually fixable as long as the board was not damaged somehow. Here are some steps to try:

- Double-press the reset button on the Arduino board and try again - sometimes this will be enough to get things working again
- Disconnect all jumper wires from your Arduino and try to upload an example program (like File/Examples/Basics/Blink) to the bare Arduino board. If this works, then you might have had a short circuit somewhere causing an issue with USB communication.
- Try unplugging/plugging the USB cable back in, try a different USB port, and reboot your computer

Please let me know if any of those steps work.

Thanks,

Ben