I'm after options to power multiple sensors in my house. They are a combination of Aeotec Zwave sensors and NodeMCU based (8266) sensors. They can both be powered by USB power and there are battery options available for both. Battery life for the Zwave gear is good, but it's atrocious for the wifi based gear.
I can see my options as:
1) Batteries. This isn't really feasible given how hungry the ESP8266 devices are.
2) mains powered USB PSUs everywhere. Messy and would require extension cords etc...
3) Low voltage (12V) power bus through the roofspace with 12V to USB adaptors breaking off the bus for the Aeotec gear and powering the NodeMCUs directly.
4) [edit - just thought of this] Could I use powered USB hubs in a couple of places? Is USB power ok across a 5 metre run on a decent cable? How about on a rubbish cable?
Option 3 looks the most attractive to me but a couple of questions...
- Do I need an electrician to install a 12V power system? Can I do it myself without breaking any laws/code?
- I presume with reasonable sized wire and PSU there would be negligible voltage drop across a 20-30 metre run? (All the devices seem tolerant of 9 volts at worst on the low end)
- Assuming it is permissable, what would be a good PSU to use? I figure with up to 10 devices drawing maybe 100ma each, a good sized 3-4A PSU would be ample?
Any other suggestions?
Cheers - N