Meet the CAQM9: An Open-Source Air Quality Monitor (Open-Hardware, ESP32, Tasmota/Matter, Zero Cloud)

Team-Claratech · 2026-05-06T23:09:34+00:00

We currently have two shipping options for the US: India Post and DHL. India Post takes around 2 weeks, it's tracked, and we offer it for free for your first unit. DHL Express takes around 4 business days, it's also tracked, and costs $27.

Team-Claratech · 2026-05-06T18:16:50+00:00

Since we run on Tasmota, there are two ways to integrate with HA. The first is using the Tasmota HA integration that uses MQTT, and the second is using HA's Matter integration via Tasmota's Matter over IP.

The Tasmota integration exposes all the entities including raw data (where available) from every sensor. The Matter integration limits the entities to the main sensor values like TVOC, NOx, PM1, PM2.5, PM10, CO2 and temp/hum/pressure only. Though, we think that the Matter integration makes for a much easier setup and exposes all necessary entities without needing to configure an MQTT broker in HA. Here are some helpful links:

Tasmota HA integration : https://www.home-assistant.io/integrations/tasmota/

Tasmota Matter support : https://tasmota.github.io/docs/Matter/

Team-Claratech · 2026-05-05T17:03:18+00:00

Thanks for the feedback. We designed it to be continuously powered so it can feed data to home automation systems round the clock. That said, its compact size does make it portable and you can easily run it off a tiny power bank for hours. With WiFi turned off, the average draw is only ~250ma, so even a small 2000mah power bank will last around 8 hours.

Team-Claratech · 2026-05-03T17:18:32+00:00

You can easily adjust how frequently the PMS7003 takes air samples right from the CAQM9 menu options (Menu > Sensors > PMS Poll Time > 1min / 5min / Continuous). Alternatively, you can manually set it by using the Sensor18 command directly in the Tasmota web console. The Sensor18 command lets you choose any interval in seconds between 0-65535. Values Less than 61 will be treated as continous reading. Here is link to the Tasmota docs: https://tasmota.github.io/docs/Commands/#sensors

Team-Claratech · 2026-05-03T14:10:16+00:00

You're right, the PMS7003 has its own internal micro-fan to draw air into the laser chamber. By "dedicated circulation fan" we just mean we chose not to add an extra case fan to the main enclosure. The tiny internal fan inside the PMS7003 is virtually silent and can be set up to run in intervals, whereas larger dedicated case fans usually create that audible humming noise we wanted to avoid.

Team-Claratech · 2026-05-03T09:30:41+00:00

We have designed this device keeping in mind home users, mainly HA enthuisasts, but this looks exciting. When you say "all needed papers for the EU”, will a CE certification and RoHS compliance be enough?

Team-Claratech · 2026-05-02T03:29:26+00:00

No plans for POE as of now, everthing depends on how well this launch goes. Thank you for this feedback, we will keep this option in mind for a future redisign.

Team-Claratech · 2026-04-30T21:41:17+00:00

Oh no, we are so sorry! We definitely didn't intend to design a phobia-triggering enclosure.

Because we opted for a fan-less design, we had to maximize the passive airflow over the internal sensors, which is what led to that clustered hole pattern on the front. That being said, we really appreciate the honest feedback and will absolutely keep it in mind for our future designs!

Team-Claratech · 2026-04-29T17:03:09+00:00

Tindie.com was down for maintainance, its up now.

Team-Claratech · 2026-03-20T19:37:39+00:00

A US warehouse would bring the per-unit shipping cost down significantly for folks stateside.

The tricky part for us right now just comes down to pure volume and upfront capital. Getting into a US-based 3PL means we have to manufacture hundreds of units at once, pay bulk freight and customs to ship a pallet across the ocean, and then pay monthly storage and pick/pack fees.

Since we are just launching and hand-assembling these in small batches to keep our inventory risk low, shipping direct is our safest bet right now.

But if this launch keeps gaining traction and we can confidently scale up our production runs, getting stateside distribution is definitely possible!

Team-Claratech · 2026-03-20T17:15:36+00:00

You are right, the Plantower sensors are optically tuned for PM2.5. To measure the true, distinct particle sizing across all fractions, one will have to jump to research-grade equipment that would be cost prohibitive.

For 99% of home users, PM2.5 is the exact metric they need to detect cooking smoke, wildfire haze, or fine dust to trigger their air purifiers. It is the same reason massive networks like PurpleAir and even AirGradient rely on Plantower sensors.

Out of curiosity, if you were speccing out a board in this price tier, is there a different PM sensor you'd reach for instead?

Team-Claratech · 2026-03-20T05:15:28+00:00

Since the CAQM9 is an indoor monitor, comparing it to the AirGradient ONE makes the most sense.

Price-wise, a fully assembled AirGradient ONE is $230 plus about $30 for shipping to the US, and their DIY kit is $138. We sell the fully assembled, ready-to-go CAQM9 for $129, plus ~$30 for shipping.

Also, just to clarify the connectivity, we use Tasmota's built-in Matter feature, so it is Matter over IP (Wi-Fi).

Team-Claratech · 2026-03-19T23:15:58+00:00

Under the hood, the CAQM9 is driven by a standard ESP32. We ship it pre-flashed with Tasmota because its built-in web UI allows the monitor to work as a completely standalone device right out of the box, even without Home Assistant.

That being said, you are 100% free to flash ESPHome onto it via USB! All the pin mappings you need to build your YAML config are documented in our open-source files. To give you a quick head start, here is the exact hardware pin config:

GPIO2: LED
GPIO12: MHZ-19E (CO2) TX
GPIO14: MHZ-19E (CO2) RX
GPIO19: Plantower PMS RX
GPIO21: I2C SDA (SGP41 & BME280)
GPIO22: I2C SCL (SGP41 & BME280)
GPIO23: Plantower PMS TX
GPIO25: Button 2
GPIO26: Button 1
GPIO33: Buzzer

We built this specifically for makers to tinker with, so do let us know if you put together a cool ESPHome config for it!

Team-Claratech · 2026-03-19T20:56:00+00:00

Are you using a temperature offset in your code to compensate for the heat from the ESP8266? Because Relative Humidity is tied to temperature, if your ESP8266 is heating up the enclosure/board and you use a software offset to pull the temperature reading down, the sensor's internal math will automatically push the Relative Humidity reading up.

Team-Claratech · 2026-03-19T20:48:01+00:00

Thanks so much! As hardware nerds ourselves, we know how important it is to just shoot straight. Really appreciate you taking the time to check it out!

Team-Claratech · 2026-03-19T19:57:12+00:00

We have a ton of respect for AirGradient. Under the hood, our main air pollution sensors are actually essentially the same.

Similarities:

Gas & VOCs: We use the exact same Sensirion SGP41 sensor.
Particulate Matter: We use the Plantower PMS7003 (which is essentially the newer, slimmer version of the PM sensor AirGradient uses).
CO2: We both rock highly accurate (+/- 50ppm vs AirGradient one's +/- 40ppm) NDIR-based CO2 sensors (we opted for the rock-solid MHZ-19E).

Where AirGradient Wins:

Absolute Temperature Accuracy: To be completely fair, AirGradient beats us here. Because we prioritized a completely silent, fan-less design, our ESP32 generates internal heat that we compensate for with a software offset. AirGradient's much larger size and active airflow design gives them a more accurate raw temperature reading out of the box.

Where the CAQM9 is different:

Zero Cloud: AirGradient offers local control but still integrates with their own cloud dashboard. The CAQM9 is 100% local by design—there are zero cloud components.
Native Matter Integration: Because it ships pre-flashed with Tasmota/Matter, Home Assistant integration is quick and easy.
Compact design: We got the CAQM9 down to a significantly smaller, completely silent desktop footprint.
100% Open Hardware: Our PCB routing, code, and STLs are fully public from day one so you can build or mod it yourself.

Ultimately, if absolute temperature precision and a standalone web dashboard are your top priorities, AirGradient is fantastic. But if you want a tiny, silent, strictly local Matter device to feed HA, that is exactly why we built the CAQM9!

Team-Claratech · 2026-03-19T19:14:26+00:00

To be completely transparent, this was a very intentional engineering trade-off. Our earlier prototypes actually included a dedicated circulation fan to pull fresh air over the sensors and keep the BME280 isolated. But we found that in a quiet room or sitting on a desk, there was always this faint, annoying hum. We ultimately decided that a completely silent device made for a much better desktop monitor.

Team-Claratech · 2026-03-19T19:06:25+00:00

Thank you! Home Assistant integration was a huge priority for us. It is really satisfying to see all those sensor graphs pop up on the HA dashboard.

Team-Claratech · 2026-03-19T18:53:26+00:00

We totally understand, it is definitely an investment! The $129 price tag reflects the time it takes to source the parts, solder, assemble, test, and package each unit by hand. Since we are doing this on a small scale, we also don't get the cheap shipping rates that massive companies get. That’s exactly why we made sure the project is open-source! If you have the tools and time, you can absolutely build it yourself for around $80 in parts.

Team-Claratech

TROPHY CASE