The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired soil moisture sensor module. The soil moisture sensor module , built around the LM393 comparator, gives ...

Note that with the “DFR” sensor, we get a signal output very close to VCC (in digital mode) when the sensor is not submerged or is in clear water (and a bit lower than that in analog mode). Here’s one ...