Hello good afternoon,
Probably i didn't explained very well, the problem is, I don't want to use any power source or external battery, I would like to use the power of the ring to power the arduino and keep it with power even with the light on or off I know there a way to do that, but is not so straightforward.
- You want the loop, while the switch is OFF to power the Arduino.
- You want the loop, while the switch is ON to power the Arduino.
Bit of a problem, in case 2.
Where are you going to get the current to power the Arduino, if your only source is now short circuit.
Looks like you want to remote control a wall light switch that only has the loop wire connected to it, no neutral.