Gravity Analog Soil Moisture Sensor for Arduino

This resistive DFRobot Gravity soil moisture sensor passes a small current through the soil via two electrodes and measures the resistance. Moist soil conducts better than dry soil, the output voltage rises with moisture. The electrodes are coated with electroless nickel immersion gold (ENIG), which protects the nickel from oxidation. The sensor works at 3.3 V and 5 V and is suitable for indoor plants, short measurement series and teaching.

Resistive sensors corrode in permanently moist soil within a few days. For continuous operation DFRobot recommends a capacitive sensor such as the DFRobot Capacitive Soil Moisture Sensor.

Recommended Accessories:

• Dupont Cables M-M 10cm 20 Pieces
• Gravity IO Expansion Shield for Arduino V7.1

Features:

• Resistive measurement with two electrodes
• Electrodes with nickel gold coating (ENIG)
• Analog output 0 to 4.2 V
• Operation at 3.3 V and 5 V
• 3-pin Gravity connector

Application Examples:

• Watering reminder for indoor plants
• Soil moisture experiments in class
• Simple short-term irrigation control

Documentation:

• Wiki DFRobot SEN0114
• Example code for Arduino (DFRobot wiki)
• Schematic (PDF)

Technical Data:

• Manufacturer: DFRobot
• Manufacturer SKU: SEN0114
• Supply: 3.3 V or 5 V
• Output voltage: 0 to 4.2 V
• Current consumption: 35 mA
• Guide values (DFRobot wiki, Arduino analog value): 0 to 300 dry, 300 to 700 moist, 700 to 950 in water
• Wiring: blue analog output, black GND, red supply
• Surface: nickel gold (ENIG)
• Dimensions: 60 × 20 × 5 mm (DFRobot)
• Weight: 14 g

Scope of Delivery:

• 1× Gravity analog soil moisture sensor
• 1× Gravity sensor cable 3-pin, 30 cm