[goodusername]

You might be interested in https://radicale.org/v3.html. Runs on my odroid board with 26mb memory. The documentation is particularly good. I've used it as a replacement for the Synology CalDav and CardDav services.

It's very easy to install and does not require a DB. As a bonus, it stores everything as files which can be read and edited manually. It does require python.

[c_prompt]

I had played with it for 2 days before I gave up. I don't remember what specifically wasn't working properly but it didn't. Even if I had gotten it to work, syncing between a Windows PC and Android device should not require that level of effort.