Introduction: Leafi a Leaf-shaped Air Quality Sensor

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About: Where 3D printing meets electronics, and serious builds don't take themselves too seriously. βš™οΈπŸ’‘ It’s all about making cool stuff β€” one project at a time.

A Leaf But Smarter


Leafi is a leaf-shaped air quality sensor designed to raise awareness about indoor pollution in a fun and educational way. Powered by an MQ135 sensor and a WS2812B LED strip, Leafi visualizes air quality in real time by transitioning from green to redβ€”green when the air is clean, red when it's polluted. It also features multiple lighting modes, including ambient animations and a relaxing "lounge mode", with adjustable brightness to match any atmosphere. Fully open-source and 3D-printed, Leafi is eco-friendly, customizable, and perfect for makers, educators, and anyone who wants to make the invisible visible.

Supplies

Electronics:


  1. 1X MQ-135 Sensor https://tinyurl.com/yc4zb3pc
  2. 1X Arduino nano https://tinyurl.com/2wdw9s6p
  3. 1X Female USB-C Connector https://tinyurl.com/54vz655f
  4. 1X 330Ξ© resistor https://tinyurl.com/2fp34p7y
  5. 1X Male USB-C connector https://tinyurl.com/tsd4apfx
  6. WS2812B 5V Led strip (144 Leds/m) https://tinyurl.com/56exza8c
  7. 1X 6Γ—6 momentary push button https://tinyurl.com/yxjv8f8m
  8. 1X 5v USB-C Power supply

Tools:


  1. Soldering iron & solder
  2. Hot glue gun or epoxy or cyanoacrylate glue
  3. 2X M3 and 2X M1 screws (or just more glue)
  4. Wire cutter/stripper
  5. Optional: translucent filament for the leaf (for best glow)
  6. Jumper cables

3D-Printed Parts:


  1. LEAFI_BODY
  2. LEAFI_BOTTOM_CAP
  3. LEAFI_BOTTOM
  4. LEAFI_BUTTON
  5. 2X LEAFI_LEAF-BICOLOR
  6. LEAFI_SWITCH_HOLDER
  7. LEAFI_TUBE

All parts can be printed in PLA


**You can also download my full instructions pdf file :)**

Attachments

Step 1: πŸŽ₯ Watch the Demo

RGB vibes for eco-nerds πŸŒˆπŸƒ

Step 2: πŸ› οΈ Assembly

No screws required for the printed parts– it's all snap-fit

Female USB-C connector is glued to LEAFI_BOTTOM.stl


πŸ”˜ Installing the Button

Insert the LEAFI_BOTTON.stl in the hole, then place the 6Γ—6 mm momentary push button on top of the LEAFI_BUTTON.stl. Then, carefully place the LEAFI_SWITCH_HOLDER.stl on top to hold it in place.

⚠️ It might take a bit of gentle persuasion β€” don’t worry, Leafi won’t bite! πŸ˜„

Once everything is aligned, I recommend adding a small dab of glue to keep the button nice and snug.

Now your Leafi is ready to click and glow! 🌟



Step 3: πŸ”Œ Wiring

Components connected to Arduino Nano

MQ135 Sensor

VCC β†’ 5V

GND β†’ GND

AOUT β†’ A0


WS2812B LED Strip (61 LEDs)

DIN β†’ 330OHM RESISTOR β†’D6

+5V β†’ 5V

GND β†’ GND


Switch Button (6Γ—6mm)

One leg β†’ D2

Other leg β†’ GND


And plug the male usb-c to the arduino and connect it to the female usb-c plug


The Arduino Nano and the MQ135 sensor can be mounted using M3 and M1 screws, but you can also glue them in place instead of screwing.

Step 4: πŸ€– Arduino Code

Upload the code to the arduino nano !

Attachments

Step 5: πŸƒ Leafi – Quick Start Guide

Power

πŸ”Œ Plug Leafi into a 5V USB-C power source.

Modes

Leafi features 4 lighting modes:

  1. MEASURE – Color changes based on air quality
  2. LOUNGE – Ambient color animation
  3. SPOT – Static light for focused use
  4. WAVE – Slow, flowing color transitions

πŸ•ΉοΈ Hold the button to switch between modes.

Brightness

πŸ’‘ Short press the button to cycle through brightness levels.

Enjoy the glow!


Step 6: πŸ“Έ More Pictures