Make water meter smart for 20 euros

I would like to monitor our water consumption, also to be warned in time enough in case of leakage. But… our water meter is stupid! It doesn’t even have a magnet for a reed relay or a holder for a light barrier.

You can buy smart water meters for hundreds of Euros and have the official water meter installed in the back for hundreds of Euros again. Fortunately, there are resourceful tinkerers and geniuses interested in the common good (from my point of view) who have coded something together. So let’s make the water meter smart.