Ok I have the following Shelly devices in a 40Ft RV/bus/motor home that has an aluminum/stainless steel infrastructure. Think almost faraday shield!!! The interior of the bus is mostly plywood in one form or another which the Wifi signal should pass though. Sometimes works, sometimes fails.
My current active Shelly devices are:
1 EA Shelly Power monitor for 240V/120V split phase power monitoring.
4 EA Shelly H&T's with external power.
2 Each Shelly 1's as simple voltage input sensors for:
1. Shore power input
2. Current power input source is 240V slit phase.
5 EA Shelly 1PM's four of which will automatically be online if the bus has AC power via:
1. Inverter off of house solar/battery storage
2. Shore power when in RV Park
3. Diesel generator
The house battery/solar system supplies always on Ethernet with POE to to:
1. Ubiquiti NanoSwitch Outdoor 4-Port PoE Passthrough Switch (N-SW)
2. Ubiquiti Networks airCube ISP Wi-Fi Access Point
3. Ubiquiti EdgeRouter X Advanced Gigabit Ethernet Routers (Teleport link to home and corporate LAN)
The airCube Access point is the connection point via 2.4GHZ for all Shelly devices.
Every Shelly device is configured for MQTT as inputs/outputs for Node-Red automations.
The major problem is that the Wifi, connection is not reliable!!! Maximum link distance is 20 feet...
It worked when I first developed the software and automations, mostly works when I am out in desert.
Fails when there is other possible 2.4GHZ traffic that it could hear or heck it might be the phase of the moon.
Another variable seems to be the firmware release where 1.9.X seemed to break everything on all devices.
I had to revert to 1.8.3 to get anything to work.
I would like to buy more Shelly hardware (looking at motion sensors), but thinking that I have gone down the wrong path at this point giving the lack of basic connectivity.
I will probably wake up shivering in the morning as I have used Shelly for my climate control and everything is falling due to flaky Wifi connectivity.
Note there is other devices on the WiFi network like tablets, TV's and other non Shelly devices that just work every time!!!