Shelly sells a smarthome sensor called Door/Window2. It works well, use wifi, is very configurable and can be used locally, without cloud. Unfortunately they’ve chosen a weird, expensive battery option, CR123A. It can cost around 70 NOK (~10 USD), and does not exist as a rechargable option. And you need two of them! So what do you do if you only have one left?
Use a single, abundant 18650 instead!
In Norway electricity is the most popular form of heating for households at 96% (source). Pure 230V AC is a very high-level energy, and we don’t really need that precision for heating.
This is a project to see if easy, not-perfect, locally generated energy can be used to lower the heating bill.
Disclamer: this is mostly for fun. A more economic aproach would be insulation, heat pump, put on a sweater, etc.
By request, a quick how-to on setting up your own realtime monitor for ruter.no, Oslos public transit.
Done!
Ruter has an API, so you can go crazy and implement your own client easily, like I’ve done with rutercli. But there’s a much simpler solution. They’ve got a website in the same style as their public monitors, mon.ruter.no. You can start with the link above, and find the numbers and names you need from a normal ruter.no search. You’ll also find NSB stuff there. See ruter.no/reiseplanlegger/sanntid/egen-sanntidsskjerm for more info.