Lumi notices I've sat down and counts down to start my study session, no buttons needed.
When nobody is at the desk, Lumi rests and waits. Its eyes blink, look around and change expressions.
Topics I miss in the quiz become weak spots, shown right on Lumi's screen (here: TCP & UDP).
Ready when you are: sit down to start a 20-minute session. Themes like Cat, Starry Night and Crimson Web make the page my own.
My study cockpit: today's mission, focus score, streak, and an AI session report that suggests my next session length.
Session complete! At 00:00 Lumi plays a happy tune, and the page celebrates with a break reminder.

Inspiration

Whenever I studied, I forgot to start a timer, or forgot to stop it when I took a break, so I never had a real record of my study sessions. I wanted something that records my sessions for me. With Lumi, I just sit down at my desk and it starts recording. When I get up, it pauses. Then it helps me review what I studied with study plans and quizzes from my own notes.

Lumi is for students who study at a desk and want their study sessions recorded automatically, without pressing start and stop, plus an easy way to quiz themselves on their own notes.

What it does

Lumi detects when I sit down within 40 cm for 5 seconds, greets me ("Hi Omaima!"), and starts my focus timer by itself.
When I get up, the timer pauses straight away and Lumi says "Come back soon…". When I sit back down for 5 seconds, it carries on.
Lumi keeps a total of my study sessions for the day and saves it even if the device loses power.
Lumi's eyes blink, look around and change expressions during a session and when nobody is around.
The web app connects to Lumi over USB and shows the same timer, today's study total, and my session settings.
I can upload my study notes and write in a built-in notebook.
The AI study buddy (Google Gemini) makes study plans from my notes and quizzes me with 5 questions, grading each answer and explaining the right one.
Topics I get wrong become weak spots, shown right on Lumi's screen (for example, "weak spot: TCP & UDP"), and "Find my weak areas" gives me a short review plan.
I can pick a theme (Lumi, Leopard, Cat and more) to make the page feel like my own.

How I built it

Hardware: Arduino Uno, HC-SR04 ultrasonic distance sensor, 0.96" OLED display, buzzer, and push button, inside a pink robot-style case.
Session recording: The Arduino detects when I'm at the desk and saves my daily total in EEPROM so it survives power loss.
Web app: An HTML web page connects to Lumi through USB using Web Serial and mirrors the timer.
AI study buddy: A Node.js server stores my notes and uses Google Gemini to write study plans, quiz questions, and grading from them.
Development: I used the Devpost Learn skills, where the AI interviewed me and turned my answers into a scope, PRD, spec, and checklist. The key decisions were mine: switching to a distance sensor so walk-bys don't count, giving Lumi eyes with pupils and many expressions, a countdown I set myself, and a button to start a new day. Then we built it in small slices, and I tested each one before moving on.

Challenges I ran into

Electronics: I was completely new to Arduino and electronics, so learning to wire the components and read sensor data was a challenge.
Reliable detection: My first idea used a motion sensor, but it triggered when someone simply walked past. I switched to an ultrasonic distance sensor so Lumi only starts when I'm sitting at the desk.
AI errors: During testing, I found that an AI error could end a quiz and lose my progress. I tested this by turning off Wi-Fi mid-quiz, found the bug, and fixed it so progress is preserved.
AI limits: Gemini's free tier only allows a small number of requests a day, so I had to plan my testing and demo carefully to stay within it.

Accomplishments that I'm proud of

Lumi works from start to finish: I sit down, the session starts, the eyes react, the quiz uses my own notes, and my weak spot shows up on Lumi's screen.
I went from never touching an Arduino to building a working device in its own case, with a web app and an AI study buddy.
Every feature was tested and checked off before moving on.

What I learned

How to connect sensors, a screen, and a buzzer to an Arduino, and save data so it survives power loss.
How a web page can talk to a device over USB.
How to work with an AI agent: let it interview me, plan first, build in small pieces, and write down what "working" looks like so bugs are easy to catch.

What's next for Lumi

Water reminders during long study sessions.
Focus Lock mode: building on the current Focus mode, the page switches to a full-screen focus screen that hides distractions until the countdown reaches zero, with an emergency exit button for anything urgent.
Move-and-stretch breaks: when the timer runs out, Lumi buzzes, its eyes change to an excited expression with a "Time to stretch!" message, and a notification on the computer suggests a short walk or stretch.
Smart break check: during the break, the ultrasonic sensor checks whether I actually left the desk. If I'm still sitting there, Lumi gives a gentle reminder to get up.