Assistive Technology - Visual Timer for Deaf Students

The asitive timer is an interactive visual countdown tool built with a Raspberry Pi Pico and a 16x16 NeoPixel LED grid. It allows users to select a duration between 5 and 60 seconds, and visually tracks the passage of time by gradually filling the grid from red to orange to green. Buttons are used to start, pause, reset, and trigger a colorful “party mode” animation. Because it uses bold, bright color transitions rather than sound, this timer is particularly useful for deaf or hard-of-hearing students who benefit from visual cues to stay aware of time limits during activities, tests, or transitions. The clear lighting provides an accessible way to monitor time without the need for auditory or numerical alerts.

Raspberry Pi Pico - W

16 Buttons

32 Pin cables

Breadboard

Laser Cut Box (design attached)

16 x 16 individually addressable grid https://www.amazon.com/dp/B088BTYJH6?ref=ppx_yo2ov_dt_b_fed_asin_title

Portable Battery Pack

Micro USB to USB Cord

This was painstakingly annoying. My one piece of advice is be either really good at soldering OR carve out a lot of time and be prepared to fail and for things to not work!

Spaghetti wiring incoming!!!

Instead of using a graphics package, I manually designed each number using a map of the pixels and told circuit python which pixels to light up for each number. Lots of manual coding here but this was the best method I could figure out!

The timer code for the Raspberry Pi Pico uses a 16x16 NeoPixel LED grid to visually represent a countdown timer. When a user presses one of several time-selection buttons (like 5, 10, or 30 seconds), the grid flashes a bold pixel-based number design showing the selected time. When the start button is pressed, the timer first performs a short color countdown flashing the entire grid red, then orange, then green. This gives a visual “ready, set, go” cue. Then, the grid progressively fills pixel-by-pixel in a smooth order, changing color stages from red to orange to green as time runs out. Each button is attached to a GP pin on the Pico and is monitored with debouncing for detection. The program constantly checks for button presses in a loop and updates the grid accordingly, making it a fully visual countdown system without the need for any sound cues.