Cumulus Support

For the last 6 months I have added pm2.5 and pm10 air quality data to my weather site. I use a cheap SDS011 sensor (under 20$ on eBay or Aliexpress, incl. a serial-2-usb adapter), attached to the same Raspberry PI that runs my Fine Offset weather station. A small Python program reads the data every 10 seconds, computes the 10 minute min/max/avg values and uploads them to the web site.

During the 6 months the device has been running continuously without major problems. I have only two "complains": a) the fan gets really noisy at temperatures below -20°C and b) the data are unreliable in high humidity (fog). While a) might be irrelevant to most Cumulus users, b) might not be.

Has anybody else had experience with this device?

Not specifically with this one. But the unreliability of PM sensors in high humidity (and high and low temperatures) are quite well known. They can be calibrated for that but even then the low cost sensors are simply inaccurate at high/low temperatures and high humidity.

I made a post with some articles.
You may find some things of interest there.

The sensor is so cheap, I actually run two of them. Both of them show the same average readings, with differences only in the 2nd or 3rd decimal digit. I haven't noticed any inaccuracy yet due to high or low temperatures, only high humidity (rain doesn't seem to be a problem, just fog). The data sheet specifies a working temperature of -10°C / +50°C with a max. relative error of 15%. While I will probably never reach +50°C, I'm waiting for the first -30°C of this winter. Hopefully, the unit will still work.

Because of our remote location far off from urban or industrial pollution, the air quality is consistently good. It's only during the wild fire season that the air quality gets bad, at times very bad. During September/October, I could actually see slightly higher PM values, most likely caused by the forest fires in Oregon and California, some 600+km to the south. With the utility program DustSensorViewer you can actually "see" a diesel truck drive by on the road in the small blip of the real time graph.

At the early stages of playing with a few of these.

Have had a couple of SDS011's for the past year & a few months later bought a couple of Sensirion SPS30's.
The Sensirion's are what I'm more interested in.

Planning on hanging them of ESP32's & having them hopefully present a URL with a JSON containing their data.

By no ways familiar with either the ESP or Arduino world, but have help in that area & programming experience on PIC Micros with a BASIC language.
(Not sure how many know that ESP32's are supported in the Arduino IDE. That was outside my knowledge base).

If anyone here has similar interests, I'm happy to collaborate.

Cheers

Maybe this can be useful
https://sensor.community/en/sensors/airrohr/
It is a project that uses an SDS011 (or other sensors) with an ESP8266.

I build one of them and it is running from months.

The firmware is open source but you can use only the binary.