HCDE 439 · Physical Computing

Runkai Zhang

I document my physical computing projects here, including the circuits, firmware, and observations behind each assignment.

View the source on GitHub

Assignments

My ELEGOO UNO R3 circuit with separate red, green, and blue LEDs.

A1: Holiday Lights

Three independent LED rhythms, current-limiting resistors, and a six-second repeating pattern.

My Firefly toy circuit on a breadboard beside the ELEGOO UNO R3, with the red LED lit.

A2: Firefly

A light-up toy that rests with a red glow and wakes into blue and pulsing green while its button is held.

My Daylight Monitor circuit on a breadboard beside the ELEGOO UNO R3, with the blue and green LEDs lit.

A3: Daylight Monitor

A photoresistor voltage divider that fades green to blue as a room loses light, with a red alert when it gets too dark.