Custom Talking Plush Toy

In this project I'm recording my daughter's voice and making her a personalized plush toy. Kids absolutely LOVE hearing their own voice come from toys. In this example I'm installing the completed sound box into a stuffed unicorn plush toy, but really you can use this same process to add a voice to anything. You can also include sound effects, singing, or other music.

This can be easily adapted for other toys, games, robots, or art projects.

Step 1: Parts and Stuff You'll Need

To make a personalized plush toy, you'll need a way to record your child's voice and edit the sound files. This can be done simply with your webcam and a free audio editor. You'll also need the electronics for storing and playing back your recorded audio. To do this I'm using Foxonix, which is an awesome, easy-to-program platform for playing audio and controlling the program.

Parts:

• Foxonix Fox Development Board

• Foxonix Project Board

• Small speaker

• One pushbutton

• Battery holder for two or three batteries (AA or AAA)

• Wire

• Microphone, Webcam, or Smartphone for recording your voice

• Audio editor like Adobe Audition, Wavepad (free), or Audacity (free)

• Soldering iron and solder

• A small plastic or cardboard box for housing the electronics

• A stuffed animal or other toy you wish to add sound to

Step 2: Recording Your Child's Voice

An easy way to record your audio is through the webcam on your computer, but if you have a fancy microphone you can use that instead. You will also need an audio editor like Adobe Audition, WavePad (free), or Audacity (free), which you will use to record your files, trim the beginning and end of your recordings, adjust the volume of the recording, etc.

For each phrase you want to include, you will make a recording and name the file accordingly, for example: hello_my_name_is_sparky.wav or i_want_to_be_your_friend.wav. To do this:

• Open a new blank audio file for recording.

• Speak the phrase into the microphone.

• Stop recording.

• Listen to the playback to see if you're happy with it, and re-record as necessary.

• Trim down the audio by removing any noise or dead space from the beginning and end of the recording.

• Convert the sample type to a lower sampling rate, like 12kHz. The audio editor should have a function for doing this.

The image above shows what a recorded audio file looks like in Adobe Audition.

NOTE: You could also record all your phrases at once and save it as a single file. Then you can copy the individual phrases out of that and save each one as a separate file.

Step 3: Hardware and Software

We're going to start by hooking up the Fox Development Board. This will allow you to test out the existing program so you can play around with it and see how it works. The Fox Board should be plugged into your computer with a USB cable. Here are the connections as shown in the diagram:

• The speaker is plugged into the PWM jack.

• One push button is connected between pin P1.0 and 3.3V

All of the software files used to create this project can be found on GitHub. You can download these files and use them as the basis for your own program. The program won't change much, but you'll be swapping in your own audio files that you made.

To test the existing program with the hardware before you make any changes, use the Fox Hardware Programmer to load the file custom_plush.bin onto the Fox Development Board. After the program is loaded, you should be able to press the button and hear the phrases.

Step 4: Updating the Program to Include Your Phrases

To make changes to the program you will need the Code Editor which is part of the Foxonix software bundle.

You can customize the program to include the phrases that you recorded by simply moving your audio files into the program folder and changing the file names in the program. You may also need to change the program a bit depending on the number of phrases you want to include, since you may have more or fewer phrases than the sample project.

After you've made your updates and recompiled the program you can load the new program on the development board to test it out.

Step 5: Programming the Project Board

After you've updated your program and you're happy with how everything sounds, you can load the program onto a Project Board for installing into your toy. One of the super cool things about Foxonix is that the development board has the programming connector built in, so you can simply plug the Project Board into that connector and load up the code. Now you have a small, stand alone PCB with your program and audio on it, which is perfect for putting into projects.

Step 6: Putting The Electronics Together

Now it's time to assemble the electronics into a housing. You can use a small cardboard or plastic box; in this example I'm using an off-the-shelf plastic enclosure.

You'll need to drill some holes for the speaker and then attach the speaker by hot gluing a thin bead all the way around the outer edge of the speaker.

In this example I'm using a 2 AA battery holder which I've hot glued to the bottom of the box.

The speaker and buttons are wired up to the Project Board the same way as on the development board in Step 3:

• The speaker is connected to the PWM pads.

• One push button is connected between pin P1.0 and Vcc.

You also need to connect the positive (+) lead from the battery pack to the Vcc pad and the negative lead (-) to the GND pad.

Finally, the board is placed inside the box, and the box is screwed together so that everything is safe inside. I cut a small notch in the side of the box so that the wires for the button can pass through.

Step 7: Putting the Electronics in the Plush

The plush unicorn I'm using already has a velcro opening for a sound box, which is what gave me the idea for this project. If you're using a plush toy that does not have an opening, then you will need to cut an opening in the skin and (maybe) remove some stuffing to make room for the sound box. You should be able to add Velcro to the skin to hold it closed, or maybe something as simple as using safety pins will work (though you wouldn't want to use pins with a young child).

This whole assembly is placed inside the plush and the button is placed in a good location where it can be easily pressed. Some suggestions are in the hand or paw, the nose, or the belly, depending on the type of plush toy you're using.

Good luck, have fun, and let me know if I can help you with anything! Thanks!