I bought a sonoff mini r2 with the intention to automate my bedroom light. It requires a neutral wire to work, so it was quite difficult to use in my room due to light is connected in a two way switch and it does not have neutral wire. Eventually, I sorted it out by pulling a neutral from a plug close to one of the switches. However, in the process I screwed it up…

I accidentally connected the neutral wire in the S1 input (which is actually connected to ground) of the sonoff while wiring the manual switch and I blew up the D4 diode.

Luckily, nothing else was damaged. I just lost the feature of the manual switch. Nevertheless, If I connected the S2 (which is GPIO04) to another exposed ground, the manual switch worked. So I ended up making a "bridge" (I think the English term is "jumper") between the ground and the S1 connection. This is the result:

The drawback is that if by accident, again, I connect the hot or neutral wire to the S1, the whole device is going to be fried. I tried to solder a diode for protection but due to the small space in the enclosure, sometimes the relay got stuck, like if it was inducted by the diode, so I decided to remove the diode.

Anyway, if someone face the same problem I hope this helps them out.

BTW, I ended up removing the sonoff mini r2 and instead installed a smart light bulb.

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