The plantower devices were nice and small. But in the end I settled on the SDS011 simply because it can be connected to without soldering. In my use case - making it accessible to beginners - that was the most important factor. I've also found that "how precise is it" doesn't matter all that much. In a home you just want an indication. After a while you just start to think in about 5 levels, ranging from "bad" to ''great". These cheap devices aren't precise enough to use in situations where you would care about precision, such as official measurements. So my recommendation is to forget about this.

This thread reads like an Agathie Christie novel. Well done on finding it!

Small update to the situation. With awesome work done by @jkandasa, the main developer of MyController the InfluxDB backend is now fast enough to almost keep up with the data inserted, that's a big improvement. This means the last issue I had with MyController just got resolved :D and it's suitable for my use-case. Yay!

It turns out that V_UNIT_PREFIX is not supported by OpenHAB's MySensors binding.

@Avamander I'm using OpenHab together with influxdb and grafana. All running on the same RPi. influxdb collects temperatures from half a dozen sensors and also a rain gauge every 2-5 minutes. Grafana plots the values every five minutes. OpenHab has rather a steep learning curve but the support forum is excellent. Openhabian is the easiest way to get running with OpenHab on and RPi

Well... Usually gw should be stable on its own. Building a redundant system because of the "unstable" power source, to me is just a much more complicated patch than simply solving the root cause.