I've read (and checked) that on the shelly1 the gpio ground pin is directly connected to the N pin. So it should not possible to use the gpio when the shelly1 is powered with 240V AC. Is it true?
Can the temp addon be used when the shelly is powered with high voltage? Or it is usable only with 12V power supply?
What are the dangerous on doing that and which are the operations that absolutely must be avoided wen powered with high voltage?
This part related to the security is not well documented and it is very important in my opinion.
Could you explain the differences in connections and power supply?
I found some information here, but still it is not clear to me:
"The shelly 1 GPIO cannot and should not be used while connected to mains voltage. While the sonoff makes reasonable efforts to isolate the high voltage and low voltage side of the board, the GPIO headers on the shelly are directly tied to the AC lines. Specifically the ground on the header is tied directly to the hot wire or line voltage pin from the AC input. I repeat, do not ever attempt to use the GPIO header of the shelly 1 when it is connected to mains voltage because the ground is referenced to your mains voltage."
Thank you in advance for your help on this