Thanks again, learned a lot... I decide to give a try there, I also had a look on some components' datasheet and seems to be what I need... Let's see, if end up getting the boards I'll publish a review here later.
Hi,
I finally received the boards from the manufacturer(big thanks to @Seeed-Fusion). I manage to assemble one board by soldering the components and such and...it WORKS(including OTA)! I will post the instructions on openhardware.io project page.
@DavidZH - I really hate our electrical system here, but that is coming from an electronics guy, not a electrician. I like the idea of low voltage in the switches, however its AC. I would prefer to see DC, but the voltage drops might be something that they're attempting to avoid by sending AC instead. Yes, i agree about those damn rings and we also don't have the room here in the UK like you mentioned about the NL.
Hi all,
Should anyone face the same problem, I found the root cause: brownout threshold. I burned a new bootloader (Optiboot 8.0) without such trigger and the node has been working with used batteries (~2.7V) since May.
Hope this helps.