Know what you breathe, without sending it to the cloud.
Araksas is a small air quality station you build yourself. It measures fine dust, CO₂, temperature and humidity, and keeps every reading on a server you own.
Why another air monitor
Most consumer monitors are closed boxes that upload your data to a vendor's cloud and stop working when the vendor loses interest. Araksas takes the opposite approach.
Your data stays yours
Readings go straight to your own server. No accounts, no vendor cloud, no telemetry.
Runs on very little
The node sleeps between measurements and runs for months on a single 18650 cell with a small solar panel.
Repairable by design
Off-the-shelf parts, a printable enclosure and plain firmware. If something breaks, you can fix it.
How it works
Four simple pieces. Each one can be replaced without touching the others.
Sensor node
Wakes every five minutes, takes a set of readings and averages them.
Transport
Sends a compact packet over Wi-Fi, or over LoRa when the node is out of Wi-Fi range.
Server
A single small service stores readings in SQLite. A Raspberry Pi is more than enough.
Dashboard
Charts, daily summaries and an optional alert when CO₂ or PM2.5 cross your thresholds.
Hardware
A typical node costs roughly the same as a mid-range consumer monitor, but every part is replaceable.
| Part | Purpose |
|---|---|
| ESP32-C3 board | Controller and Wi-Fi |
| Laser PM sensor | PM1.0, PM2.5, PM10 |
| NDIR CO₂ sensor | CO₂, 400–5000 ppm |
| Temp / humidity sensor | Ambient correction |
| 18650 cell + 1 W panel | Off-grid power |
| LoRa module (optional) | Long-range link |
Server
The server is a single binary with a config file. Start it, point your nodes at it, open the dashboard.
# config.toml
[server]
listen = "0.0.0.0:8080"
database = "readings.db"
[alerts]
co2_ppm = 1200
pm25_ugm3 = 35Readings can be exported to CSV at any time, so you are never locked in.
Questions
How accurate is it?
Low-cost PM sensors are good at showing trends and spikes, less so at absolute values in very humid air. Araksas applies a humidity correction, but it is not a certified reference instrument.
Can I put it outdoors?
Yes. Use the vented enclosure and mount it under a small roof, away from direct sun and rain.
Is there a ready-made kit?
Not at the moment. The project is built and maintained in spare time. The build notes describe every step.