

I built a thermostat with a Wemos D1 mini and a relay module about 10 years ago.
Still use it today integrated with home assistant and can turn the heat on and off while away from home. It’s been reused across three boilers, no parts replaced.
It was a really fun project and I had virtually no experience with Arduino when starting out. Would recommend it to anyone.
Looks like someone decompiled it and compared it to RTEMS code.
What I don’t get is that RTEMs appears to be dual licensed, with one being under BSD… So they would just need to attribute somewhere and then they would be fully compliant.
Maybe the bigger picture is more complicated than that though.