The AustSTEM Foundation

This soil moisture arduino sensor uses the two probes to pass current through the soil, and then it reads that resistance to get the moisture level. More water makes the soil conduct electricity more easily (less resistance), while dry soil conducts electricity poorly (more resistance). This sensor will be helpful to remind you to water your indoor plants or to monitor the soil moisture in your garden.

Specification

• Power supply: 3.3v or 5v
• Output voltage signal: 0~4.2v
• Current: 35mA
• Pin definition:
  • Analog output(Blue wire)
  • GND(Black wire)
  • Power(Red wire)
• Size: 60x20x5mm(2.36×0.79×0.2″)
• Surface finish:Immersion Gold