Introduction: Acoustic Tractor Beam

Picture of Acoustic Tractor Beam

Tractor Beams are mysterious waves that can attract particles towards the source. Here, we will show you how to build an Acoustic Tractor Beam with components that can be bought directly on the Internet for less than 75$.

With this Instructable you will be able to get in your hands a device that it was only seen on SciFi movies such as Star Wars or Star Trek.

If you want more scientific background on Acoustic Tractor Beams, you can check our Open Access research papers:

Do not forget to watch the attached video in this Instructables.


If you want to build other devices coming directly from the research lab keep in touch:

Youtube: https://www.youtube.com/user/asiermarzo
Twitter: @AsierMarzo

Step 1: Gather the Parts and Tools

Picture of Gather the Parts and Tools

We present a list of the necessary components. I have tried to place links for different countries. However, the same parts can be found all around the world, some useful websites are http://www.findchips.com/ http://www.dx.com/ http://www.miniinthebox.com/http://www.lightinthebox.com/http://www.banggood.com/

The circuit is not complicated. Basically, an Arduino will generate 4 half-square signals at 5Vpp 40kHz with different phases. These signals get amplified to 25Vpp by the Motor Driver and fed into the transducers. A button pad can be used to change the phases so that the particle moves up and down. A battery (7.3V) powers the Arduino and the logic part of the Motor Driver. A DC-DC Converter steps-up the 7.3V to 25V for the Motor Driver.


Components:

  • 30x 16mm 40kHz Transducers The MSO-A1640H10T are the best but minimum order is 500, they are good so perhaps you can save them for future ultrasonic projects. Alternatively, others 16mm 40kHz transducers will serve (emitters and receivers are pretty much the same) for instance the MCUSD16P40B12RO.

Necessary Tools:

  • 3D printer -> you can use an online service
  • Soldering Iron, Tin and Flux.

  • Drill

  • Hot-glue gun

  • Multimeter

  • Cable Peeler

  • Screwdriver and Pliers.

Step 2: 3D Print the Bowl

Picture of 3D Print the Bowl

The transducers will be mounted in this bowl. This shape allows to naturally focus the beam.

We used an Ultimaker Extended 2+ with a 0.4mm nozzle and the Normal settings. No support, only brim. It does not need to have a perfect finish so any regular printer should work.

Step 3: Solder Arduino Headers (upwards If Possible)

Picture of Solder Arduino Headers (upwards If Possible)

Step 4: Program Arduino

Picture of Program Arduino

Upload the attached program in the Arduino Nano. If you are using a cheap Nano (totally recommendable) you will need to install new drivers, there are usually links in the webpage where you bought it.

Step 5: Charge the Battery

Picture of Charge the Battery

This way when you finish the project it will be at full charge.

Step 6: Cut the Handler

Picture of Cut the Handler

300x45x15mm rectangular piece of wood.

Step 7: Redrill the Bowl

Picture of Redrill the Bowl

Sometimes the holes are not perfect and are a little bit clogged, re-drill them if it were necessary.

Step 8: Attach the Bowl to the Handler

Picture of Attach the Bowl to the Handler

Drill an initial hole in the handler, attach the central screw and then you will be able to drill the two holes at the sides.

Deattach the bowl, it is more comfortable to attach and test all the components without the bowl. At the end of the Instructables we will reattach it.

Step 9: Screw the DCConverter and the Driver

Picture of Screw the DCConverter and the Driver

Close the the drilled holes for the bowl we will place the DC-DC converter at one side and the Driver at the other. Put them and mark with a pen to drill later. Then pass a screw and a nut through the holes of the devices for being able to attach them properly to the wood.

It is very important to leave the OUT side of the Converter closer to the bowl.

Remove the indicated jumper of the Driver and keep it for later.

Step 10: Stick the Arduino

Picture of Stick the Arduino

With Velcro tape, double sided tape or just hotglue stick the Arduino below the Driver with the USB port pointing to the right.

Put the jumper between the D10 and D11 pins.

Step 11: Drill Through Holes

Picture of Drill Through Holes

Drill two through holes above the Driver.

Drill tree through holes below the Arduino.

We will pass wires through these holes.

Step 12: Solder Wires to the Power Switch

Picture of Solder Wires to the Power Switch

The central pins provides the current to the circuit, the right pins go to the DC barrel and the left ones to the battery connector pins.

Try to use red wires for (+) and black for ground (-) to keep things ordered. Pay attention to where the + and - of the DC barrel go and solder it appropriately.

For the battery connector pins we can use pin headers and a tiny piece of strip-board. Be sure that the wires are not touching each other (use a multimeter), and even put hotglue between them to make them safer.

The power switch provides current to the circuit either from a DC barrel or from the battery.

We can use any DC adaptor between 9V and 12V that can provide at least 2A if you do not want to use a battery.

Step 13: Stick the Battery

Picture of Stick the Battery

With double-sided or Velcro tape. Do not use hot-glue since it could damage the battery. Put it in the same orientation as the image.

Step 14: Connect the DCConverter With the Driver

Picture of Connect the DCConverter With the Driver

These wires will pass the step-up voltage (25V usually) from the DCConverter to the Driver.

Step 15: Glue the Power Switch

Picture of Glue the Power Switch

Step 16: Connect Logic Supply

Picture of Connect Logic Supply

We will provide 7.4V to the DCConverter IN.

First connect the black ground wire (-) from the central pins of the Switch into the DCConverter IN(-). In the same hole connect the ground for the Arduino.

Then, connect the red (+) wire from the central pin of Switch into the DCConverter IN(+). In the same hole put the VIn of the Arduino, and the logic supply for the converter (pins from where we removed the jumper, very important to connect it into the highlighted pin).

Tining the tips of the wires will facilitate putting several wires in the same hole.

It is also possible to get voltage for the Arduino from the DCConverter. Instead of connecting Converter.IN(+) to Arduino.VIn, we can use DCConverter(5V) to Arduino(V5).

If it is too difficult to put various wires into the sockets of the DCConverter, you can also solder to the pads that are at its sides.

Step 17: Connect Signal Wires

Picture of Connect Signal Wires

These four wires will transfer the signals from the Arduino into the Driver.

Connect Arduino.(A0,A1,A2,A3) to Driver.(IN1,IN2,IN3,IN4).

Step 18: Button Pad

Picture of Button Pad

The button pad is optional, but if you make one you will be able to levitate the particles up and down.

The idea is to have three button pads that when pressed they make contact with ground (the buttons are active low).

Get ground from the Arduino to the common terminal of the buttons. Then, connect each of the buttons to D2(up), D3(down) and D4 (reset position).

Step 19: Set the Voltage to 10V

Picture of Set the Voltage to 10V

First Connect the battery (be sure to use the right polarity).

Switch on the device.

Rotate the potentiometer counterclockwise until you see 10V in the display.

In the final device we will use 25V but it is safer for the test equipment to work at 10V. If you use X10 probes then it is alright to use 25V throughout the process.

Step 20: Test the Signals

Picture of Test the Signals

This step is optional but it is about time to check that everything is working fine.

Get two probes and connect the grounds to a ground of the circuit, temporarily using the button pad ground is one of the easiest options. Remember to put it back when finished.

Before the driver the signals should be 5Vpp and after the driver 10Vpp.

Signals from the same side are in phase while signals from opposite sides should be out of phase.

Step 21: Mark the Transducers (Obsolete Method)

Picture of Mark the Transducers (Obsolete Method)

The transducers have polarity and they need to be marked. Do not trust manufacturer marks since they can be wrong.

This method is the one contained in the video, but we have an alternative one that is much easier one in the next step.

First take ground and voltage from any of the Driver outputs. Connect them to a transducer and also connect one probe to the same transducer. This probe will capture the emitted signal.

Take another probe and connect it to the transducer that needs to be marked, this will be the received signal.

Put the transducers face to face and check the signals in the scope.

If the signals are in phase, mark the leg connected to ground. If they are out of phase, mark the other leg.

Mark all the transducers.

Step 22: Mark Transducers (Preferred Method)

Picture of Mark Transducers (Preferred Method)

This method for marking transducers is much easier than the previous one.

Just connect one probe to the transducer.

With a metal wire poke gently and repeatedly the inside of the transducer. Check the signal in the scope, if the first spike goes up, mark the ground leg. If the spike goes down, mark the other leg.

Step 23: Mount the Transducers

Picture of Mount the Transducers

Put the transducers in the sockets with the marked legs pointing upwards (towards the top).

You do not need to populate the bottom row.

Step 24: Wire the Transducers (hard Method)

Picture of Wire the Transducers (hard Method)

We need to wire the transducers to deliver power into them.

Measure the needed length for the wire and give three extra hands for connecting it later.

With the cable peeler, partially peel at the correct distance, later these exposed parts will be twisted around the transducers legs.

Once that you have made the cuts with the peeler, redistribute the plastic to keep a uniform length of cooper exposed. Twist the cooper wires to make them more solid. Twist the exposed parts around the transducers legs, apply flux and solder.

Follow the pattern presented in the images. That is, all the grounds are connected together. The red wires of the same half go towards the same side.

Pay attention to the numbers, these numbers correspond to the driver numbers.

Step 25: Wire the Transducers (Simple Method)

Picture of Wire the Transducers (Simple Method)

It is the similar to the other method but using exposed wire.

Step 26: Test the Transducers

Picture of Test the Transducers

This step is optional but it is convenient to check that all the transducers are connected correctly.

Connect the ground from the bowl into the driver ground (there will be another wire there).

Connect the 4 red wires from the bowl into the outputs of the Driver, respect the numbering.

Connect two extra marked transducers to the scope probes. Be sure to connect the ground into the marked leg (or at least connect the two transducers in the same way). With these transducers we can check the emitted signal of other transducers.

Transducers from the same half of the bowl should emit in phase. Transducers from opposite halves emit out of phase.

Transducers with the wrong polarity should be desoldered, rotated and resoldered.

Step 27: Set Voltage to 25v

Be sure to set the DC-DC converter to 25V using its potentiometer.

Step 28: Attach the Bowl

Picture of Attach the Bowl

Now that all the components are in place, it is time to reattach the bowl into the handler.

Step 29: Connect the Wires

Picture of Connect the Wires

Connect the ground from the bowl into the driver ground (there is already another wire there).

Step 30: Switch on and Levitate

Picture of Switch on and Levitate

Switch on the device, you should be able to feel a little bit the sound, or hear it if you point it into a big chunk of expanded polystyrene or foam.

Using an acoustically transparent sheet or tweezers you can place particles in the centre of the bowl (above 1.8cm approx) and they will be levitated.

Push the buttons to move the particle up or down.

Depending on the size of the particle and how close it is to the bowl, you will be able to levitate it laterally or upside down. It is also possible to levitate particles that are resting on a surface.

Step 31: Building Other Sonic Devices (Optional)

We have presented how to build the most efficient device but there are others that require even less electronics although they are not as efficient in terms of levitation power to watts.

For the following devices you will need smaller transducers, wires and connectors, as well as a different version for the Arduino (that generates always a 40kHZ signal).

Step 32: Coils Device (Optional)

Picture of Coils Device (Optional)

Print the attached STL file. The transducers are fit in the bottom holes and they are all driven with the same signal.

Step 33: Tubes Devices

Picture of Tubes Devices

Print the attached STL file. The transducers are fit in the bottom holes and they are all driven with the same signal.

Step 34: Miscellaneous Files

Raw design files (Inventor)

Comments

CKapahi (author)2017-09-18

Hi, I was curious how the up and down buttons controlled the focal point of the speakers. I tried to read the Arduino code, but it still wasn't clear to me whether the focal point was being altered by changing the frequency the speakers were driven at, or changing the phases of the speakers somehow. Thanks for making all this so easily available by the way!

Asier Marzo (author)CKapahi2017-09-19

Hi, glad that you like it.
to move the focal point we change the phases. Each period is divided into 24 steps of 0s and 1s by shifting the patterns we change the phase:
000000000000111111111111 -> phase 0
000000111111111111000000 -> phase pi/2

the phases are precalculated for the different points and hardcoded in the code (that is why there are a lot of hex constants).
Best,
Asier.

jcwildfire (author)2017-08-11

Hello, thank you very much for the how to on this. I am apart of a school project that is building the pinch set up. However, we are having trouble with transducers. We cannot hear them making any sound to speak of, and the voltage out of the driver is .1V. The Arduino is responding to all commands that we give it, and the dc-dc is working well with its outputs. We have tested the transducers to properly mark positive and negative legs. have you experienced an issue like this?

Asier Marzo (author)jcwildfire2017-08-13

Could you post some pictures of the driver?
Are all the red lights from the Arduino, DCConverter and Driver on?

jcwildfire (author)Asier Marzo2017-09-08

Thank you very much for your response. We managed to get it working temporarily (fantastically I might add), however, when we tried to drop the voltage to see how that would alter the acoustic trap, the unit stopped working. We tried for awhile to get it back. Do you have any suggestions?

The original problem was the Lan Driver was bad.

Asier Marzo (author)jcwildfire2017-09-09

How low the voltage went? the ideal value would be 20V int the DCDC converter. It will not be able to produce less than the input voltage.

Do you have a scope to test if the Arduino is generating the signal and if the driver is amplifiying it?

jcwildfire (author)Asier Marzo2017-09-10

Yes we have a scope. We will test that these components this coming week. The voltage was down around 23 V and .22 A when working, the issue we had arises at around 16 V.

The nano is getting warm now with a voltage of less than 10 V. I think i may need new components.

Asier Marzo (author)jcwildfire2017-09-11

With the scope you should be able to check if the Arduino is generating logic signals and if the Driver is amplifiying them. I recommend running the device at 20V (no more than 25V) I think it should consume more amps at that voltage.

jcwildfire (author)Asier Marzo2017-09-08

.

jcwildfire (author)2017-09-08

Thank you very much for your response. We managed to get it working (fantastically I might add), however, when we tried to lower the voltage to see how that changed the acoustic trap, the unit stopped working above the given voltage. Do you have any suggestions?

The original problem was that the Lan Driver wasnt working properly, and we had a different set of transducers that could not provide the proper frequency.

Hello Asier,

Thank you for sharing the instructions of this device. I'm actually trying to go a step further with the acoustic levitation by making a device with four phased array able to manipulate objects with ultrasounds. And while I was searching documentation, I found your device called Levipath. And by reading it's PDF, I wanted to ask you how you are able to change the phase of the signal of the speakers. So can you explain that to me or at best share the computer code of Levipath.

Best regards

For complete 3D control we were using an independent channel for each transducers. We were going to publish a driver board based on Arduino MEGA that can drive 64 channels, although it is a little bit tricky with the electronics. We also include software to control any array. The research is still under review but if you send me private message with you e-mail I can send the stuff to you.

I have sent a mail to you. Thank you for the fast response.

thomascw123 (author)2017-02-24

hey, my driver board keeps on messing things up. The red one. It only lets through 0.10 volts out of its outputs. WHY is this happening. It is not working anymore because of this.

Dingusboy17 (author)thomascw1232017-08-04

Were you able to fix this? I am having the same issue

Asier Marzo (author)Dingusboy172017-08-25

Could you post a picture of the driver with the connections?

Hi thomascw123 and Dingusboy17

I had the same problem as you two and I found out that by putting a jumper on the driver where we're supposed to remove one, in my case, the led of the driver turned on and the driver worked perfectly. This jumper is a 12V jumper and have to be removed when using a supply voltage greater than 12V DC. (https://www.instructables.com/id/Control-DC-and-stepper-motors-with-L298N-Dual-Moto/).

RazvanOpre (author)2017-08-24

Hello ! First I want to say is that this project is amazing . I want to make it for my final project and I really need to know if i can use MSO-A1640H12T instead of MSO-A1640H10T Is there any difference if I use them ? I am asking because they let me buy 100 of them instead of 500 . Thank you very much ! I uploaded the data sheet .

Asier Marzo (author)RazvanOpre2017-08-24

They should be fine. If you are going to use 16mm diameter transducers you can only use BigLev or MidLev. BigLev needs to be 3Dprinted in two parts and then glued since it will not fit the printer. At the end of the Instructables I have just added MidLev a levitator that uses 16mm diameter transducers but that will fit most of the printers, it can also levitated liquids.

Asier Marzo (author)2017-08-18

Those tests that you did are quite good.

1. The bowl has a single focal point, it can move the particles because it changes the phases of the signals.

2. Those devices are less powerful.

3. That would be one solution.

In any case, if you want to levitate heavy stuff I totally recommend you the Instructables that just got published ( https://www.instructables.com/id/Acoustic-Levitator/ ). It can levitate water, insects and even glass.

TaeZ1 made it! (author)2017-08-16

Hi


Asier,

Thanks for answering my question. It seems
that the Sculpted surface type that you provided it can lift only foam I have trying lift object size 1.235 * 0.7 *
0.18 mm Weight 0.4 mg by using tweezer place object in the center of the bowl but it can’t float. So I tried to levitate this object that are resting on a surface appears that it floats above the ground a little and moves along the bowl of the transducer but can’t float I think this is because the object is too
heavy. So I proved by fill it in the foam diameter 2 and 3 mm it can to be floating
this indicates that the pressure wave is strong enough to lift an object 0.4 mg But the size of this object is too small so I tried to cut foam into cubic size 0.5, 1, 2, 3, 4 mm ^ 3 and smaller than that object float and adjust the

voltage supplied to the motor driver board (l298n) gradually decrease until

these foam are fallen only foam size 4 mm ^ 3 can’t float the rest floating
show that the problem is not at the size and also found that foams about 2 mm ^ 3 are use the lowest voltage when increasing the size of the
foam, it is necessary to have more the voltage due to the greater weight of foam but when the size is lower than 2 mm, it has to increase the voltage. I think that's because when the size of the surface is smaller, the surface area for get pressure is reduced wave, it is necessary to increase the voltage so that the pressure wave has a larger amplitude according to this picture. Now I want to lift the object size. 1.235
* 0.7 * 0.18 mm Weight 0.4 mg Density 2.33 mg / mm^3 but the foam used to lift. Have a density of 0.024 mg / mm^3.I was hesitant about doing something between

1. Redesigned the bowl
to have a total focal point at a single point.

(I understand that the prototype you provided does not have a single focal point so it be able to levitate the particles up and down).

2. Building Other
Sonic Devices such as Tubes Device or Coils Device.

3. Add more transducer
and more voltage as much as possible.

If you were me, what would you do? Please guide me. And
what program do you use to simulate this situation?

Best regards.

LyH9 (author)2017-07-10

Hi Asier,

I have levitated the particles and I can manipulate it randomly.Besides that, I used a different up instead of Arduino. I want to manipulate it to a position that I desire but I don't know how to calcutate the phase delay for each trans. I also read yours some papers about this but it seems quite complicated to me understand and apply.

Can you give me the simple way to calculate the phase delay to manipulate the particles for a wanted position?

Asier Marzo (author)LyH92017-07-11

For doing that you will need individual control on each of the transducers (one channel per transducer). We will publish soon a driver board capable of controlling 64 channels as well as software to create traps at arbitrary positions. If you give a thorough read to this paper http://aip.scitation.org/doi/full/10.1063/1.4972407 there is a clear formula for calculating the phase.

LyH9 (author)Asier Marzo2017-07-12

Can you give me a software can apply the formulas which you recommend for me to calculate the phase for each trans? I think it will use a software can simulate all parameters (pressure, the density of particles, distance...). (it's quite complicated to do).

Asier Marzo (author)LyH92017-07-12

Could you send me an email to amarzo@hotmail.com, we have a paper that explains how to use the software but it still has not been published. I can send it to you.

LyH9 (author)Asier Marzo2017-07-13

I have sent a mail to you. Please check mail box and response my mail. Thank you so much.

m150159 (author)2017-07-06

Hi Asier,

It is definitely great job! Superb.

I made it with Manorshi transducers (they actually send 100 or less, but a bit more expensive).

1) Now I am keen to build the pinch (standing wave) from the following video:

https://youtu.be/vLCrm6gos4w?t=28

Is there a way you can share stl or raw files and code? I assume i will need MSO-P1040H07T, correct?

2) As for the tubes one (above), what is the connection diagram? Hardware list?

Thank you

Asier Marzo (author)m1501592017-07-07

Glad that you like it.
1) for the pinch you will need the 10mm transducers. I used the lasercuter to create the base, but you should be able to cut manually a piece of plywood or just use perfboard. It is just 7 transducers in a hexagonal pattern with the central one out of phase. Feed the same signal into all the transducers but flip the polarity of the middle transducer.
2) for the tubes you need a 8x8 flat platform of 10mm transducers. you can feed the same signal to all of them.

If you like levitaiton keep in touch, we are about to publish a single-axis levitator that can levitate liquids and insects. It uses either the 10mm transducers or the 16mm.

Best regards,
Asier.

m150159 (author)Asier Marzo2017-07-07

Hi Asier,

Thanks for prompt reply.

Do you mean standing wave one, by saying single-axis?

Are the 10mm from Manorshi good? Should I go on with them?

as for 2) what is same signal? Just one or the OUTs of L298N?

Thank you

Asier Marzo (author)m1501592017-07-10

Yeah, by single-axis I mean a standing wave one.

The 10mm from Manorshi are not as good as the Murata but they are certainly much cheaper and can do the job almost as well. I almost always use the Manorshi.

Same signal as you said just use the 1 OUT of the L298.

taez (author)2017-07-02

Hi Asier,

Thanks for sharing this great knowledge. I was glad to see the object floating

I’d like to ask you a few of questions

1.If we wanted to lift a larger object, would we have to lower the frequency? On the other hand, if we want to lift a smaller object, would we have to larger the frequency? And when we increase or decrease the frequency, will it affect the weight that can be carried?

2.Is it possible to lift the very much smaller object about 0.5*1*1 mm and 0.0003 gram ?

3.If we need to lift heavier object, do we need to increase the pressure amplitude by increasing the voltage?

Asier Marzo (author)taez2017-07-03

1. With the current approaches the object size is limited to aprox. half-the-wavelenght, so as you said the only way is to decrease the frequency, there are comercial transducers operating at 32 and 25kHz but they are a little bit pricey. I have levitated 0.5mm objects at 40khz but I do not know what is the minimum size. How the frequency affects the power is tricky because different factors: ++ higher frequency is more directive so the energy gets more focused, -- higher frequency attenuates more while travelling through air, ++ high frequency carries more energy.

2.I think so. Although very small objects behave strangely and may orbit around the nodes instead of getting trapped into them.

3.Yeah for denser objects you need more force, therefore more pressure, therefore more voltage. However,those transducers usually cannot take more than 40Vpp and the driver will definetly overheat. If you want to levitate heavy objects I recommend to use our upcoming single-axis levitator.

Instructables: https://www.instructables.com/member/Asier%20Marzo/
Youtube: https://www.youtube.com/user/asiermarzo
Twitter: @AsierMarzo

cerrituss made it! (author)2017-04-29

I used this Ultrasonic sensor transceiver from Aliexpress, seems to work.

https://de.aliexpress.com/item/Ultrasonic-sensor-transceiver-integrated-diameter-40KHZ-16MM/32767545603.html

mosivers made it! (author)cerrituss2017-06-18

Hi,

I got the same transducers but they do not fit properly into the bowl (see pictures). Did you modify the bowl in some way? The diameter of my transducers is 11.4 mm, height is 11.8, what was the original bowl designed for?

I am wondering whether it would be possible to leave out every second transducer in the upper row, how would this affect the performance? So far I did not manage to levitate anything and the object is always pushed out, probably because there is no proper focus.

I would appreciate your advice.

Best,

Moritz

FredS52 (author)mosivers2017-06-27

I tested many sizes of styrofoam spheres, and if it is too big/heavy, it is pushed out. 3mm work just right for me. The density also is important.

- Double check the phase of each transducer.

mosivers (author)mosivers2017-06-19

Hi Asier,
Sorry I meant the diameter is 16.4 mm not 11.4 mm. Maybe scaling the bowl up a little bit is the easiest solution.
Thanks,
Moritz

cerrituss made it! (author)mosivers2017-06-19

Hi there

I didn't any modification of the stl file. I got the same problem as you but with some kindly force to my transducers I managed to properly fit them in. They may be under some little strain I gues but it works.

I also got some "jumping" of little things but i managed it with some little grid, to levitate it in the middle.

Hope I could help

Asier Marzo (author)mosivers2017-06-19

Hi. The STL for the bowl is designed to support 16mm diameter transducers. Most of the transducers that I have seen are either 16mm or 10mm diameter. perhaps the easiest way is to scale down the bowl to fit the transducers.

FredS52 made it! (author)2017-06-20

I made it following the instructions one by one. Worked on the first time.

For sure I found some troubles afterwards: for those who get the step motor drive super hot, it is because the legs of the transducer is being shorted with the aluminium case. Do not bend the legs to avoid this problem.

I's running mine at 18V.

I made the body for 3D print and you can find it at https://www.myminifactory.com/object/acoustic-trac...

Thanks for amazing project!

Asier Marzo (author)FredS522017-06-20

Thanks to you Fred, that looks amazing.

KrisCross93 (author)2017-06-09

Hi Asier,

I've got the problem that I'm just able to move objects down, up and reset button are not working. When I'm moving objects down, they won't stay in position, but will levitate back to start-position as soon as I let the button go. Do you have an idea how to solve this?
Best regards. Kris

Asier Marzo (author)KrisCross932017-06-09

Sounds like a strange behaviour. Could you try to bypass the button pad (the problem may be in it) and directly connect GND to D2 (down), D3 (up) or D4 (reset) with a jumper wire to check if it works properly. Best Regards, Asier.

KrisCross93 (author)Asier Marzo2017-06-09

Hey, thank you for your fast reply. Already tried that, still not working :/ I'll try another Arduino on Monday, if you got any other ideas let me know.
Best Regards, Kris

KrisCross93 (author)KrisCross932017-06-14

Replacing the Arduino fixed it :)

LeoB92 (author)2017-05-29

Hello
Can we use http://www.ebay.com/itm/2-Pairs-TCT40-16R-T-40KHZ-Ultrasonic-Transducer-Sensor-16mm-Ultrasonic-Probe-/131590233040?hash=item1ea3639bd0%3Ag%3AReQAAOSwGzlTv6iX instead of MSO-A1640H10T???

Asier Marzo (author)LeoB922017-05-30

It is hard to say. The size and power seem ok but the problem may be the phase deviation, especially between the emitter and receiver.

Put all the Ts in one half and all the Rs in the other.

Best regards. Asier.

LeoB92 (author)Asier Marzo2017-05-30

Thanks for your response

LeoB92 (author)Asier Marzo2017-05-30

We are currently low on budget so can we buy this or is there any other option on eBay or Amazon because minimal order in your description is 500 and its too much for us.
So is there any option on eBay or Amazon?

AndreaD20 (author)2017-05-29

Hello Asier,

I am trying to learn as much as possible from your device, and I have noticed something i haven't seen before, since I didn't have a decent oscilloscope. My tractor beam works fine, I can move the object up and down without problem. But when I check the signal with the oscilloscope, I see that the reading from the analog pins looks perfectly square, but the amplified one is noisy. Is there a way to reduce this? What might be the cause?. I attach an image.

Thank you very much in advance!!

Regards,

Asier Marzo (author)AndreaD202017-05-29

Hi Andrea, if there is no load at the output, it is common to see those spikes in the amplified signal. There should also be some spikes on the top but the scope may cap at 20Volts.

Also, in theory sinusoidal waves instead of half-square should be used for feeding the transducers but in practice the transducers are so narrow band that the output is still sinusoidal.

The important part is the output of the transducers. You can connect a transducer to the scope's probe and check the sound output.

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Bio: Do you want to build your own cutting-edge devices? Directly from the research lab. Ultrasonics, Electromagnetism and more. Researcher at Bristol University interesting in Ultrasound ... More »
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