## Introduction: Laser Projection Pomodoro Timer

Hello to everyone at their homes during lockdown. I hope this instructable helps you get through these days.

So i've been using the pomodoro technique for studying at home. For anyone who doesn't know what pomodoro technique is, it is a technique where you study/work for 25 minute intervals and take 5 minute breaks inbetween each interval. It's a really efficient way of studying and if you haven't tried it, i suggest you do.

While using the pomodoro technique i would use my phone to keep track of time and it got the job done. But when i saw this Work From Home Challenge i thought i could make a better and cooler thing to assist me and tell me when to take a break and when to study.

## Supplies

An Arduino Nano

Laser Module

28BYJ-48 Stepper Motor and ULN2003 Driver

7.4V Li-Po Battery

Small piece of mirror

Small electrical switch

3D Printer

## Step 1: The Design

For the design of this timer, i wanted it to be cool and have a circular shape like a clock. To make it cool i decided to use a laser (Lasers are cool). To make that laser look like a clock i will use the stepper motor and a mirror placed at an angle. I've drawn a small description of it above. So by placing the motor and the laser as shown above, we can project the laser on the wall in a circle.

## Step 2: Case

I designed a 3D model of the case in Fusion 360. It will be printed in 2 pieces. First piece is a small box that will contain the electronics and the seconds piece holds the motor and the laser on top of the first piece. Inside the case there is a place for the electrical switch, li-po battery, arduino and the ULN2003 driver. After designing the case i 3d printed it with black PLA.

STL files are below.

## Step 3: Circuitry

I've drawn a circuit schematic that can be found above. After drawing the schematic i soldered wires according to it. Jumper wires can be used too but i found that they take up too much place in the small case i've designed so i soldered everything.

After that i uploaded the sketch to arduino, put everything inside the case, placed the electrical switch on its slot and closed the case.

## Step 4: Code

So since this is a pomodoro timer, i wrote an arduino sketch which spins the motor at a certain speed so it takes 25 minutes to complete a rotation. After 25 minutes motor starts to spin very fast for around 5 minutes indicating it's time to take a break. After that 5 minutes it starts again and it keeps going in a loop.

Sketch can be found below.

## Step 5: Ending

I hope this inspires somebody out there to improve their pomodoro technique or to start applying the pomodoro technique because it is a really efficient way of studying.

Stay creative.

Participated in the
Work From Home Speed Challenge