OP here. Thanks so much for the fun discussion. A few things: 1. I forgot to set the repo to public -- was only meant to be private while I was writing it up!

OP here. Thanks so much for the fun discussion. A few things: 1. I forgot to set the repo to public -- was only meant to be private while I was writing it up! Fixed now. 2. Somehow I put in the table that I used an RPi 4b but this is actually a RPi Zero W. 3. Lots of great related ideas here! One project I've been thinking about lately but would probably work best as a community effort is a a water auto sampler to build into your board for getting an idea of e. coli and stuff e.g. to investigate the "don't surf after a rain".