In this Instructable you're going to record your own voice and make a personalized childrens' book! It's a really fun project and makes a special keepsake or gift.
In this example I'm using the timeless classic Where the Wild Things Are by Maurice Sendak (HarperCollins Publishers), but of course you can use any book you like.
Step 1: Parts and Stuff You'll Need
To make a personalized audio book, you'll need a way to record your 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.
1.) Foxonix Fox Development Board
2.) Foxonix Project Board (optional)
3.) Small speaker
4.) Two pushbuttons
5.) Battery holder for two or three batteries (AA or AAA)
7.) Microphone, Webcam, or Smartphone for recording your voice
8.) Audio editor like Adobe Audition, Wavepad (free), or Audacity (free)
9.) Soldering iron and solder
10.) A small plastic or cardboard box for housing the electronics
11.) Your favorite children's book
12.) Your best reading voice
Step 2: Recording Your Audio
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 page of the book, you will make a recording and name the file accordingly, for example: cover_page.wav or page5.wav. To do this:
1.) Open a new blank audio file for recording.
2.) Read a page from the book into the microphone.
3.) Stop recording.
4.) Listen to the playback to see if you're happy with it, and re-record as necessary.
5.) Trim down the audio by removing any noise or dead space from the beginning and end of the recording.
6.) 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 can also read the entire book at once and save it as a single file. Then you can copy the individual pages 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:
1.) The speaker is plugged into the PWM jack.
2.) One pushbutton is connected between pin P1.0 and 3.3V
3.) One pushbutton is connected between pin P1.1 and 3.3V
All of the software files used to create this project are included here, but can also 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 (Where the Wild Things Are) with the hardware before you make any changes, use the Fox Hardware Programmer to load the file talking_book.bin onto the Fox Development Board. After the program is loaded, you should be able to press the buttons and hear the pages being read.
Step 4: Updating the Program to Include Your Audio
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 audio that you recorded by simply moving your audio files into the program folder and updating the file names in the program. You may also need to change the program a bit depending on the number of pages you have, since your book may have more or fewer pages 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 the audio sounds, you can load the program onto a Project Board for installing into your book. 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 It All Together
Now it's time to assemble the electronics into a housing. You can use a small cardboard or plastic box, but here we're constructing a custom box with some styrene sheet plastic.
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. Drill two holes for the buttons to poke through, and then hot glue these buttons in place so that they don't move.
In this example I'm using a 2 AA battery holder. Notice that I've left long leads on the battery holder which makes it easier to remove if the batteries need to be replaced in the future.
The speaker and buttons are wired up to the Project Board the same way as on the development board in Step 3:
1.) The speaker is connected to the PWM pads.
2.) One pushbutton is connected between pin P1.0 and Vcc.
3.) One pushbutton is connected between pin P1.1 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 box can be glued together so that everything is safe inside. I used a wider plate on the bottom of the box so that there is an edge to tape to the back cover of the book.
Good luck, have fun, and let me know if I can help you with anything! Thanks!