I’ve got three weather stations based on the Electron running at different locations. They’ve been running for a few months now without any problems. I didn’t even go to check on them.
Within 24 hours all three of them stopped sending data.
Only one of them is close to me so I went and did a reset on that one. It functioned perfectly. Two days later the exact same thing happened to that station. Luckily I happened to notice lightning in the area around the same time.
It turns out that there was also some lightning when all three of them died.
My only conclusion is that the static buildup caused by the lightning is putting the MCU in some sort of infinite loop.
The software watchdog timer is implemented on all three of them already so the next step is to implement an external watchdog timer.
Hope this helps someone having some strange issues. The problem should be rare as you don’t normally mount an Electron outside on a tall pole.