Ultrasonic Levitation Not Functioning

[Dr_Incog]

I believe that I have completely followed the directions up to this point that regard the building of an Arduino ultrasonic levitator. The fact of the matter is that it does not work at all. What I mean by this is the ultrasonic transducers do not make any sound and have no electrical current running through them no matter what I do. I am currently using the 12 volt power supply with the h-bridge. The one thing that I could possible think of that is causing the project’s error is me using a different arduino board than that of what was recommended in the kit; however, this board is nearly identical to the one proscribed, being the Arduino UNO R4 Minima. The only difference is that this board has a plus and minus symbol. I will send pictures that show my setup. I am extremely eager to know how I can fix this. It’s due on the 28th of October. Thank you very much for looking at this reply. I appreciate the time you put into this. (This only seems to allow me to put a max of two images even though my other files have a size less than 5 mb)

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[DauntlessDog12]

Hi there,

Nice work so far with the wiring. It's unclear to me where you are getting the 12 volt power supply from in this diagram. Also, just as a clarification, but the white and purple wires are the positive outputs for the levitators, while the blue and grey wires are for the negative outputs? Here is a tutorial for a much clearer diagram of your wiring: https://www.sciencebuddies.org/science- ... -levitator. Basically, you should try to find some sort of external power supply that gives 12 volts. Hope this helps.

[Dr_Incog]

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I have a 12 volt plugged in and the grey wire is actually connected to the arduino. I believe to have followed the directions on the site correctly. The only thing that’s different is the word font on the Arduino board. But it’s also an r4 uno minima. I’d like to hear your thought.

[Dr_Incog]

You were also correct about what you said with the wires. The grey was just connected to the 5 volt thingy.

[bfinio]

Hi - in your pictures, there is no power going to the power bus on the left side of your breadboard (the side that is oriented toward the bottom of your pictures). I'm guessing that the 12V power supply you mentioned is plugged directly into the Arduino's barrel jack. The Arduino has an on-board voltage regulator which converts this 12V to 5V, which you then have connected from the Arduino's 5V pin to the right-side power bus (on the top in your pictures), which is all correct. But there is nothing actually providing 12V to the H-bridge to power the transducers. To do that you need to add another wire from the Arduino's VIN pin to the right-side power bus (on the bottom in your pictures).

Note that the procedure of the project suggests doing it a little differently - Figure 4 shows how you can connect an external power supply directly to the breadboard, while powering the Arduino separately over USB. This lets you use an even higher voltage power supply for the H bridges, which can handle a much higher voltage input than the Arduino (I believe up to 36V, whereas the Arduino Uno R3 was only 12V - but they've increased that for the R4). To plug the power supply directly into the breadboard, you need the adapter linked in the materials list.

[Dr_Incog]

Thank you. I´ll try this when I get back home from school. I´ll make sure to update you if it works. By the way, the power bus is the side that is positive, right?

[bfinio]

If you haven't already, I highly recommend you watch our How to Use a Breadboard tutorial video, that will explain the buses much better than I can in a comment here: https://www.sciencebuddies.org/science- ... breadboard

But short answer - the words "positive" and "power" are used somewhat interchangeably. They are usually marked with a red line and a "+" symbol. The same goes for "negative" or "ground" bus, marked with a blue or black line and a "-" symbol.

[Dr_Incog]

I ended up trying what you said and connected the vin to the right power bus, but when I started doing that, the arduino began smoking, so I’m guessing I may have accidentally shorted my circuit. I’ll send a picture to show you. I’m wondering whether or not my configuration is correct. The gray is connected to the 5 volt and the yellow is connected to the vin.

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[bfinio]

Hi - you have the gray and yellow wires both going to the same bus in the breadboard, which is shorting 12V to 5V. That is bad and would result in smoke. Note that in my previous post I said to connect Vin to the LEFT power bus (which was oriented toward the bottom the way you took one of your previous pictures).

It would help to keep orientation consistent so we can be sure we're referring to the same thing - keep the breadboard upright or "vertical" so the row and column labels are facing you and appear upright, like reading a book (not sideways).

At this point, however, I'm not sure if the short will have permanently damaged your Arduino. Does the board still appear to be working if you run something simple like the built in Blink example?

[Dr_Incog]

The board does work and I will try what you said.

[Dr_Incog]

While plugging in the vin, I think I should also plug in a usb so that the arduino, itself, can receive power. I’m thinking this because the light is flickering on the arduino, indicating a lack of proper energy. So far, however, this solution does appear to be having an effect.

[Dr_Incog]

I just plugged in the usb and all of a sudden the arduino began overheating. An orange light came on and I tested the temperature of the microchip and it was extremely hot. How do I avoid this? Don’t worry, I unplugged the arduino.

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[bfinio]

At this point I'm concerned that the short between Vin and 5V may have permanently damaged your Arduino and you may need to purchase a new one.

Note that (when everything is working properly and not damaged), the Arduino can receive power from the barrel jack, it is not necessary to keep the USB cable plugged in unless you have the external power supply going directly to the breadboard.

[Dr_Incog]

My mom agreed to buy me another Arduino board and it’s coming on Saturday. I’m buying the exact same model, so hopefully it works as intended.

[bfinio]

Ok - remember that your entire circuit needs a common ground - the negative breadboard buses should be connected to each other and to the Arduino GND pin. But when using a circuit with an external power supply, you *never* want to connect the higher voltage directly to the Arduino's 5V pin, or indirectly by connecting different voltages to the same positive bus on the breadboard (or linking the two positive buses with a jumper wire, if you have a different voltage connected to each one). It's safest to build the entire circuit and connect the external power supply last, then IMMEDIATELY disconnect it if you see or smell any smoke.

[Dr_Incog]

My Arduino is finally working and I managed to levitate a small piece of foam momentarily. Thank you so much for the help you’ve given to this endeavor. Thanks to you, my project works.

[bfinio]

That's great to hear, glad you got it working!

[faharjatoi]

Hi, could you please help me with the same experiment. Mine is not working and I'm already using a 12 V direct power supply through an adaptor to the adrino.

[bfinio]

Hi,

There are two issues with how you have power connected to the breadboard in your circuit.

- Missing ground wire - make sure you connect an Arduino GND pin to a negative (-) bus
- You're powering the Arduino with a 12V adapter, but you aren't providing the 12V to the breadboard. You need to connect an additional jumper wire from the Arduino's Vin pin to the positive (+) bus that currently doesn't have anything connected to it (on the right in your picture, although the breadboard is upsidedown, so it would be on the left if the breadboard's writing was right side up)

It looks like there may be additional things miswired in your circuit - for example, the two ground wires on the left in the image should be in rows 13 and 14, not rows 14 and 15.

It also looks like some of the jumper wires in your circuit are not pushed into the breadboard all the way, because there is a lot of exposed metal sticking out. Make sure every jumper wire is pushed firmly all the way into the breadboard.

I can't clearly see all the connections in the rest of the circuit since the wires in the way, but I would disconnect power from your circuit completely and double-check all of the wiring before reconnecting power.

Hope that helps,

Ben

[faharjatoi]

Hi Ben,
Please check now? It still doesn't work. Please let me know if i could restart the connections one by one for better visibility.
Please also note my breadboard doesn't have holes all the way there are gaps in between.

[bfinio]

Hi - it looks like you added the ground wire from the Arduino and fixed the ground wires on the H-bridge, but you are still missing the wire from Arduino Vin to the currently-empty positive bus on the breadboard. Without that wire, the ultrasonic transmitters do not have power, so the project will not work.

[faharjatoi]

Levitation is still not working . But i do see voltage if i test it with a multimeter. Please check the code if it needs changes to provide the right amount of voltage?


https://docs.arduino.cc/built-in-examples/basics/Blink/
*/

// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW
delay(1000); // wait for a second
}



/*
Generate an approximate 40kHz signal for an ultrasonic levitator.
This code is designed for an Uno R4. Delay time was determined
experimentally to get as close to 40kHz as possible. This approach
worked better than the tone() function on an R4, which actually
generated a 41.67kHz signa.
On an Uno R3, you can use the tone() function.

Parts list and circuit diagram: https://www.sciencebuddies.org/science- ... -levitator

*/

const int ultrasonicPin = 3; // pin to generate signal
const int delayTime = 10; // delay time in microseconds

void setup() { // setup code that only runs once
pinMode(ultrasonicPin,OUTPUT); // set ultrasonic pin as output
}

void loop() { // code that loops forever
digitalWrite(ultrasonicPin,HIGH); // set pin high
delayMicroseconds(delayTime); // wait
digitalWrite(ultrasonicPin,LOW); // set pin low
delayMicroseconds(delayTime); // wait
}


The voltage which is showing on the Multimeter is 5.79 and -5.82

[bfinio]

Hi - to clarify, when you do this, are you leaving the Arduino plugged into the USB cable? The Arduino still needs power over either the USB or barrel plug when the external power supply is connected directly to the breadboard. In your photos, there is no power to the Arduino.

If you downloaded the code directly from our website without making any changes, it should be correct.

Also, note that the code does not change the voltage applied to the circuit. It controls the duration of the on and off pulses, which determines the frequency of the signal. The voltage applied to the transmitters is determined by the external power supply, and the inverter (the additional chip that isn't the H-bridge) doubles this. So for example, if you use an external 12V power supply, the inverters will get 24V. However, since this voltage is rapidly toggling on and off, you cannot measure it properly with a multimeter set to measure DC voltage. To do that you need an oscilloscope, which shows a graph of voltage vs time.

Not saying you need to do that (use an oscilloscope) for this project, just wanted to clarify your understanding.

Thanks,

Ben

[faharjatoi]

I do have a oscillator also purchased just for this project not sure how to use it. Project is due Monday. Yes, I'm plugging in the power supply as well as adrino to the laptop as shown below, please let me know if there is any other way we could connect to resolve the issue

[bfinio]

Hello,

I didn't notice it earlier because other wires were in your way, but your H bridge is missing a connection to pin 1 (the top left pin). Note how in Figure 4 in the project, pin 1 of the H bridge has a jumper wire going over to the 5V power bus:

https://www.sciencebuddies.org/science- ... #procedure

That is the ENABLE pin for the H-bridge; without it, the signal will not be on.

Not sure if this message will be too late since you said the project is due today. Note that this is an advanced project and not really intended for first-time Arduino users, in case this is your first Arduino project. It's very important to get every connection on the breadboard right, and this is a pretty complicated circuit if it's your first time building one.

[faharjatoi]

The red top wire is plugged into the 5V in Adrino board. Anything else that we could try should i try adding the adopter directly to the adrino?
Is there a way to connect with you directly on a zoom call to get this done sooner?
I have requested an extension from school for few days.
This project is selected and is expected to be presented in our local county fair in California please help us out. Its really important.
I have noticed one thing after plugging it with the adopter adrino shows only one green wire is there any other lights which need to turn on when plugged in ?
My TR and RX are not lighting up after connecting it to the power but my L light lights up

[bfinio]

Hi - please see the circled area in the image below. The wire from this breadboard row is missing completely. There should be a wire going from this row to the 5V power bus. I am not referring to the wire that connects the 5V power bus to the Arduino.

Thousands of students use our site every day, and we are unable to offer direct support over Zoom. Your best bet at this point may be to find someone else who is familiar with Arduino and electronics who can help you, or to go somewhere like a makerspace where you may be able to find more people who are able to help. There have been numerous wiring errors that have prevented your circuit from working. It is very important to double and triple check every single connection, and it can be helpful to have a second person double-check your wiring.

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[faharjatoi]

Good news! I'm able to levitate object now. Thank you so much for all your support and help much appreciated

[bfinio]

That's great to hear! Glad you were able to get it to work.