Portable rain drop sensor made with Xiaomi door sensor

Hardware
141

I suspect that the rain module has a short on it. Make sure all the contacts on the board are clean on both sides. If you have an ohm meter you could test it for any shorts.

Also make sure that the reed switch is disconnected before you connect the rain module.

142

If you had power across them all the time it may have been that.

I think you need to not have voltage across them between measurements.