Introduction: Voice Changing Tube

This Tube takes your voice and modifies it from its natural frequency to a higher or a lower pitch. Its a great project to make a better alternative of many children's toys. This project is an awesome DIY for a fun new toy to have fun with whenever you like. It requires basic soldering skills and an understanding of Arduino coding and circuitry to be able to complete effectively.

This Instructable will feature mostly diagrams, because wires tend to be hard to follow.

I recommend covering any open copper wires with electrical tape or another cover so you do not cross the circuits.

Step 1: Materials

1. Wave Shield Kit V 1.1

2. Arduino Uno

3. Electret Microphone with Amplifier

4. 3 in diameter 4 Ohm Speaker

5. Audio Amplifier

6. 9V battery connector

7. AA battery pack

8. 10k Potentiometer

9. On/Off Button

10. SD card of any size

11. 3 in Diameter PVC pipe

12. Soldering Tools

13. Copper Wires

14. Electrical Tape (optional)

Step 2: Assemble WaveShield

First you will have to assemble the wave shield as it comes disassembled in the kit. I will not cover this process step by step, but the link below will walk you through the assembly if you are not familiar with it.

Step 3: Overview of the Circuit


The Circuit above is extremely close to the system used in this project and is extremely useful to refer back to when completing each step. It will help keep everything clear and organized.

Step 4: AA Battery Pack

Start by soldering a longer wire onto the positive wire of the battery pack.

Assemble the Audio Amplifier by soldering the parts together the way the amplifier is labeled

Solder the positive wire to the port furthers to the left of the audio amplifier.

Solder 3 wires onto the negative wire of the battery pack connect 1 wire each to the potentiometer, the audio amplifier, and the microphone.

Most soldering of wires will be done by poking the wire through the hole of the point, filling the space with solder and cutting the excess wire from the bottom.

I would recommend detaching the Wave shield from the Arduino when working. All ports will go through the wave shield directly.

Step 5: Soldering the Positive Wire to the Potentiometer and the Microphone

The positive, or "hot wire" of the system will separate into 3 different lines. One will go to the potentiometer, another will go to the microphone, and the 3rd will go back into the 3.3 v port of the wave shield.

Start by soldering the hot wire to the AREF port of the wave shield.

Next you will have to solder 2 wires onto the hot wire so there are 3 ends to the wire. You could also solder 3 wires onto the end of the original hot wire. One wire should go to the right port of the potentiometer, while the other should go to the right port of the microphone. The last wire will connect back to the 3.3 v port on the wave shield, completing the circuit.

Step 6: Solder Potentiometer and Microphone to Wave Shield

Solder the middle wire of the potentiometer to the analog 1 port on the wave shield. analog one is required for software provided to work with the system.

After, Solder the left port of the microphone to the analog 0 port. With these two connections the microphone will input to the wave shield and the potentiometer will be able to change the pitch of the sound.

Step 7: Solder Audio Amplifier to Wave Shield

Soldering the Audio Amp to the Wave Shield will require combining 4 wires into 2. Use the diagram above as a reference.

Take two wires. Attach one to the 4th port from the left, and the other 3rd port from the right.

Take these two wires and soldier them together; attach the one combined wire to the bottom port on the wave shield. Stick the wire through the port as far as possible and solder together. Cut the excess and leave as little exposed copper as possible.

The other two wires will attach to the two ports in between the ones just used. Solder them together and attach them to the other port on the wave shield. It is vital that no exposed copper from the wires touch each other otherwise the system might short-circuit.

Step 8: Attach Speaker to Audio Amplifier

The Audio Amplifier will have 2 pairs of ports for the wires, but this project only uses one.

You can solder the wires to the speaker so the system will be working before assembly, or you can wait until the assembly phase.

Make sure to identify which wire will be positive and which will be negative.

Using a small screwdriver screw the negative wire into the port furthest to the left and the positive wire into the one directly to the right of that wire.

With this final step, your hardware is done! All you need to do is upload the code and put it in its casing.

Step 9: Install Software Onto Arduino

Use the code provided below.

You will have to install the library WaveHC from

Then, with the library enabled, download the code at the following link onto your arduino: Adavoice

Step 10: Insert Circuitry Into PVC

For this step you are going to want to lay everything out before you begin inserting the wave shield. I suggest orienting the system so it is similar to the image above.

The microphone, potentiometer, and on button should be on one side. The batteries should be glued next to them, followed by the wave shield and arduino. On the very end should be the speaker that does not go within the tube, but sits with its edge on the outside.

Detach the 9v battery from the arduino for ease.

Use a strong adhesive like super glue to attach each component to the inside of the tube. Apply the glue to the edges of the arduino and carefully slide it into the PVC pipe, with the speakers end last. Firmly place the arduino in its spot, which will allow you to work on the rest of the system.

Make sure the 9v port is facing away from the speaker.

Now reattach the 9v battery and cord and glue the two batteries into place next to the Wave shield.

After that attach the microphone to the very end of the tube so it can read your voice. I suggest testing the sound at different points before committing to a spot. Find the point that receives the best sound.

Also glue the potentiometer and the on/off button into the the PVC pipe so they are accessible.

Finally, if you haven't yet, solder the two wires screwed into the audio amplifier to the positive and negative ports on the speaker. If you have, just Glue around the edges of the speaker and place it so it is flush to the outside of the pipe as pictured above.

With this final step your project is complete! You can maneuver the casing however best fits you and if you'd like to cover the electronics, a piece of plywood cut into a 3 in diameter circle can be used to block them, but make sure to drill a hole for the microphone, potentiometer, and on button to come through.