Gravity: Analog Soil Moisture Sensor For Arduino

A soil moisture sensor can read the amount of moisture present in the soilsurrounding it. It's ideal for monitoring an urban garden, or your pet plant'swater level. This is a must-have component for an IOT garden / Agriculture!The new soil moisture sensor uses Immersion Gold which protects the nickel fromoxidation. Electroless nickel immersion gold (ENIG) has several advantages overmore conventional (and cheaper) surface platings such as HASL (solder),including excellent surface planarity (particularly helpful for PCB's with largeBGA packages), good oxidation resistance, and usability for untreated contactsurfaces such as membrane switches and contact points.This soil moisture Arduino sensor uses the two probes to pass current throughthe soil, and then it reads that resistance to get the moisture level. Morewater makes the soil conduct electricity more easily (less resistance), whiledry soil conducts electricity poorly (more resistance). This sensor will behelpful to remind you to water your indoor plants or to monitor the soilmoisture in your garden.To ease the difficulty of using this sensor, a Gravity Interface is adapted toallow plug&play. The Arduino IO expansion shield is the best match for thissound senor connecting to your Arduino. As this sensor can work at 3.3V whichmake it compatible with Raspberry Pi, Intel Edison, joule and curie.