Shelly has very nice Add-on sensor module (companion, must be used together with Shelly I4 DC, AC and few other Shelly devices):
It adds one Digital Input, one Analog Input, one DHT22 Temp/Humidity sensors or up to five DS18B20 Temp sensors (unfortunately DHT22 and DS18B20 cannot be used together, one or the other).
I tested this Add-on sensor together with Shelly I4 DC (4 digital inputs device) with @dmitry.rozovik excellent HE driver which supports all possible input combinations.
In addition to digital inputs and temp/humidity sensors my plan is to use an analog input of these device combo as a DIY Water Leak Sensor. For the testing I picked up this water leak sensing cable:
Cable was connected between VREF+R1 OUT and ANALOG IN pins (a 100K resistor was connected between ANALOG IN and GND pins). With a dry cable the ADC reading is/was less than 8%. But even a very small drop of water on the cable immediately increased ADC reading above 90%.
So, as a result this became a very sensitive cable based and DC powered (no batteries) DIY water leak sensor which can protect relatively big area (few sensing cables could be chained together). Sensor Cable dries out within less than an hour (not too bad).
