Word-Learning Book Companion

This is an assistive technology project designed for the Campus School at Boston College. This project serves as an interactive, touch-responsive companion to a popular tactile storybook at the school, A Tail for Baby Lizard, to promote word learning and active engagement with literacy activities. When the copper tape of each animal is touched, the box speaks the name of the animal and the box gently lights up. Children can use this book companion as they interact with their favorite book. While this project was designed with a specific book in mind, this concept can be easily reproduced for other favorite books!

MATERIALS

1. 1/8" Baltic Birch laser cut with the following dimensions:
2. 2x 22in x 6in panels
3. 2x 22in x 3in panels
4. 2x 6in x 3in panels
5. 1x Raspberry Pi Pico 2W
6. 1x Breadboard
7. 1x USB-A to microUSB data cable
8. 1x Adafruit NeoPixel LED Strip w/ Alligator Clips - 60 LED/m - 0.5 Meter Long - Black Flex
9. 1x Adafruit MPR121 12-Key Capacitive Touch Sensor Gator Breakout - STEMMA QT
10. 1x STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable - 150mm Long
11. 1x Adafruit PCM5102 I2S DAC with Line Level Output - 112dB SNR
12. 1x Mono Enclosed Speaker with Plain Wires - 3W 4 Ohm
13. 1x Adafruit STEMMA Audio Amp - Mono 2.5W Class D - PAM8302
14. 1x JST PH 2-Pin Cable - Female Connector 100mm
15. 1x STEMMA JST PH 2mm 3-Pin to Male Header Cable - 200mm
16. 8x pin-pin wires
17. 7x double-sided alligator clip test leads (or similar wire that has an alligator clip at one end)
18. Copper tape
19. Masking tape
20. Felt / other fabric in multiple colors
21. 1x USB-A power supply

TOOLS / SOFTWARE

1. Adobe Illustrator
2. Audacity
3. Laser-cutter
4. Hot glue
5. Wire stripper

Using the "final lizard book companion build" .ai file and a laser cutter, laser cut the box, cut out the animal elements, and engrave the text on the 1/8" Baltic Birch.

Reproducing this project with a different book will require the use of Adobe Illustrator to design the elements you want to laser cut. Use the following instructions:

1. Take pictures of the book elements you want to laser cut into your box. For this project, I took clear pictures of the different animal characters in the book.
2. Upload the pictures onto Adobe Illustrator.
3. On Adobe Illustrator:
4. Use the Pen tool to trace the outlines of the image(s) you want to laser cut.
5. Change the stroke color to be pure red (RBG = 255, 0, 0) and the stroke length to be 0.01mm.
6. Type out the text you want to engrave and change the text color to be pure black (RBG = 0, 0, 0).
7. Click on the text, then go to Type > Create Outlines to convert the text to a path.
8. Position your designed elements on a blank version of the box - "lizard book companion build - without animals" .ai file

1. Record or collect the audio files you will use. The audio files used for this project are attached.
2. Put the audio files in a folder named "animals". Add this folder to your CIRCUITPY folder, as you will refer to it in your code.

To use your own audio files, record on Audacity and input least 100 ms of silence before and after the audio. Export as .mp3 files.

Time for some arts and crafts! Prepare your materials for bringing the animal elements to life. I used squares of felt and fabric in different colors/textures to make the animals look authentic to the book, but feel free to use whatever you have on hand.

1. Lay out the 22in x 6in panel with the laser-cut animals. Flip it over on the long end so you are looking at the inside, with the animals upside down. See image #1 for what this should look like.
2. Cut enough fabric to cover each hole.
3. Cut a strip of copper tape that is an appropriate length to be able to cover the length of the hole with a tail of tape at the end (~ 1 inch).
4. Stick a line of copper tape to the side of the fabric that will be visible on the outside through the hole -- this process may require some trial and error; make sure that the tape is covering enough of the animal body and can be easily touched. Use masking tape to hold the felt in place. See image #2 for what the tape should look like when viewing the panel.
5. Cut and strip the wire for each alligator-clip test lead. The stripped wire end will be copper-taped to the edge of the felt animal inside panel with the tail of tape. It would be best to reinforce this with another little strip of copper tape. See image #1 for what this should look like. Make sure to keep wires tidy and distant from each other.

1. Attach the bottom and two side panels of the box. As the top panel with the laser-cut animals has not yet been attached, the box should be open on the top and in front of you, so that you can wire and place the computing components.
2. Attach the Pico and DAC to the breadboard as shown.
3. With pin-pin wires, wire the DAC to Pico as follows:
4. VIN --> 3V
5. GND --> any Pico GND
6. WSEL --> GP9
7. DIN --> GP11
8. BCK --> GP10
9. Attach the 2-pin JST connector to the amp: red wire to the + terminal and black wire to the - terminal (you may need to strip the wires).
10. Connect the speaker to the amp using the JST connectors.
11. Attach the 3-pin JST connector to the other end of the amp. Wire the amp to the Pico as follows:
12. GND - Black wire --> GND
13. Signal - White wire --> GP14
14. Power - Red wire --> VBUS
15. Attach the STEMMA QT cable to the capacitive touch sensor. Wire the sensor to the Pico as follows:
16. Power - Red --> 3.3v
17. SDA - Blue --> GP4
18. SCL - Yellow --> GP5
19. GND - Black --> GND

Attach the alligator clips to their corresponding touch pad on the touch sensor:

1. Lizard --> Pad 0
2. Lion --> Pad 1
3. Zebra --> Pad 2
4. Cat --> Pad 3
5. Snake --> Pad 4
6. Alligator --> Pad 5
7. Fish --> Pad 6

Use masking tape to attach the LED strip to the back of the panel as shown in the image. You may choose to use LED pebble strands or dots strands instead of an LED strip for more flexibility in positioning the lights.

To wire the LED strip to the Pico:

1. Clip a pin-pin wire to each alligator clip - ground is black, signal is white, and power is red
2. Wire the strip to Pico as follows:
3. GND --> GND
4. Signal --> GP16
5. Power --> VBUS

1. When you are satisfied with the positioning for all components, remove masking tape and hot glue components to the panel.
2. Attach the top panel to the box, making sure the engraved words and copper tape is showing on the outside.
3. Plug the data cable into the Pico.
4. Attach the last 22in x 3in panel (the panel facing you) to the box. The data cable should be able to stick out of the box when it is closed, but feel free to make a small cut to the box for the cable is the box is not closing properly.

Attached is the code to run on the Pico. Make sure of the following:

1. You have a folder on CIRCUITPY named 'animals' that has all of the mp3 files you are using in the project.
2. Test out the code to ensure that when the touch sensor for an animal is activated, the corresponding sections of the LED strip light up (this may involve some trial and error).

When the project is working as intended, plug the USB-A side of the cable to a portable battery pack. The project is complete!