KIRA04 - AIRNODE

AIRNODE is a smart air-quality monitoring and automation system that I originally built for my bedroom workshop. It measures what I am actually breathing and, when the air gets bad, it does something about it.

Why I built it

The idea started for a slightly funny reason: I did not want to accidentally poison myself while I was sleeping.

I spend a lot of time soldering and running multiple 3D printers in my bedroom, sometimes for many hours at a time. Since I work, study, print, and sleep in the same room, I started wondering what I was actually breathing every day. That concern pushed me to build AIRNODE.

But I did not want AIRNODE to simply tell me there was a problem. I wanted it to actually respond to it.

How it works

Sensors monitor the environment → the ESP32-C3 processes the data → AIRNODE shows the readings on its round display and sends them to Home Assistant → when air quality drops, it sounds a buzzer alert and automatically turns on the exhaust fan I installed in my window to pull bad air out of the room.

Hardware

• Sensirion SPS30 – particulate matter (PM1.0 / PM2.5 / PM10)
• Sensirion SGP41 – VOC and NOx index
• Sensirion SCD40 – true CO₂ measurement
• Sensirion SHT40 – temperature and humidity
• ESP32-C3 – main controller with Wi-Fi for Home Assistant
• Round TFT display showing an air-quality rating (Good / Fair / Poor) plus live readings
• 4 mechanical push buttons for navigating screens and settings
• Piezo buzzer for instant local warnings
• Custom enclosure that I designed and 3D printed myself

From prototype to PCB

My current prototype works, but it is built with a lot of hand-wired connections inside the enclosure. It is messy, hard to reproduce, and not as reliable as I want it to be.

So I designed a custom 2-layer PCB in KiCad that brings all the sensors, the display, buttons, buzzer and ESP32-C3 together on one board that fits the enclosure, with M3 mounting holes:

Here is the current hand-wired prototype running:

Why I am applying for sponsorship

A dedicated PCB would make AIRNODE cleaner, more reliable, easier to assemble, and much closer to a finished product. With PCBWay's support I want to manufacture this board, assemble it, and move from a functional prototype to a refined device. It is also a chance for me to learn more about professional PCB design and manufacturing.

What's next

• Order and assemble the first batch of AIRNODE PCBs
• Test and calibrate the sensors on the new board and compare against the prototype
• Refine the enclosure for the PCB version
• Publish the firmware, KiCad files, enclosure files and bill of materials as open source
• Post a full build log here on PCBWay once the boards arrive
• Document the whole process on video: unboxing the PCBWay boards, assembly and soldering, first power-on, and AIRNODE reacting to real air-quality changes while my 3D printers run

What started as a personal solution for my bedroom has grown into a modular environmental monitoring and automation platform that could also be useful in 3D-printing rooms, workshops, maker spaces, soldering stations, and any indoor space where air quality matters.