Interactive Alphabet Touch Board

This project is a custom-designed interactive alphabet learning board, built specifically for the students of Boston College's Campus School. The Campus School serves students with a range of disabilities, and this project was created as part of an assistive technology project, in Professor Gallaugher's Physical Computing Course, to enhance learning through engaging, multisensory experiences.

Here are some key features:

1. Interactive Letter Sounds: Touch a peg under the board, and the it plays the corresponding letter sound.
2. Quiz Mode: The board challenges students by playing a random letter sound, and they must press the corresponding letter. Success is celebrated with colorful LED animations and positive sound effects!
3. Assistive and Inclusive Design: The system is built with simplicity and accessibility in mind, ensuring it can be used by children with diverse needs.
4. Custom Feedback: Provides multisensory feedback through audio, LEDs, and animations, enhancing cognitive and sensory engagement.

1. Raspberry Pi Pico W
2. Breadboard
3. Breadboard Audio Jack
4. Breadboard SD Card Reader
5. SD Card
6. Neopixel LED Strand
7. Lots of wires!
8. 3x Adafruit MPR121 touch pads and connectors
9. 28x nails
10. Speaker
11. Hot glue gun
12. Some 1/4" wood

Wire up all breadboard components using the tutorials provided by Prof. G. This includes the SD Card.

Daisy Chain two STEMMAQT MPR121 pads on one SPI bus and one on another.

Load this code and files into the Pico W. It utilizes a dictionary for efficient and clean code to map touchpads to letters. It has a lot of helper functions and flag variables to help with quiz mode. Additionally, it uses SD card lib code. The alphabet sound files are found online and need to be processed using Audacity to be compatible with CircuitPython

Using makercase, I created a 16x13x4.5" box and edited the alphabet letters and light holes using Adobe Illustrator. Then, using Boston College's makerspace, I cut out the box using our laser cutter.

Using hotglue was the quickest and easiest way to assemble this box. I also hotglued the LED strip to the holes.

In order to utilize the daisy chained touch pad, you need to physically solder the address 0x5B bridge to power. The code takes care of altering the address in order to have two distinct touch pads under the same connectors.

In order for students to activate the touchpads, we need to give a conductive surface for them to touch, which is connected electrically to the MPR121 touchpads. So, using a hammer and nails, hammer nails under each letter. I used a small drill bit, smaller than the nail itself, and made a hole to speed the process up.

Important! Don't forget to include two nails for free play and quiz mode so that the modes can be toggled!

The MOST tedious process is here! Now physically attach the electrical wiring to each corresponding touchpad and letter. Be sure to be careful not to mix up the letters! And ensure a strong connection is made and is working before hot gluing permanently!! I used color coordinated wires and zip ties to keep the absurd amount of wires somewhat manageable. I also glued the nails to take away any sharp nails.

Feed attached power cords through extra holes and attach breadboard with stick pad to the back panel.