It turns out that it’s pretty dang gratifying to build embedded systems. Don’t like the power LED that’s always on? It’s your code that turns it on! You can turn it off!
I have three projects that are functional so far. One logs temperature to a MicroSD card, which helped convince the leasing office that my fridge was not cooling well enough to be food safe. Another displays CO2 sensor readings. The third sends door close/open events over MQTT.
Currently I’m working on giving a kitchen scale the MQTT treatment so I can make detailed cat food consumption graphs over time instead of manually weighing for two inconsistently timed data points per day. Next will probably be designing and printing a case for the CO2 thing, which is currently just a bunch of components taped to a power bank, and is very flimsy.