Sensors

Multiple sensors are used in the system, the main sensor being the moisture sensor.

Moisture Sensor

Moisture sensors are simple and act on measuring capacitance between 2 points. As the soild dries, the capacitance lowers. So simply put, you have 2 options for the sensor, DIY or commercial:

DIY

• Gypsum [1]
• Galvanized Steel [2]

Commercial

• VG400 [3]
  • $29.99
• Cheap Hand-held Moisture Sensor; Product: [4] Hack: [5]
  • $10.99