RE: Arduino-based Smart Watering of Plants

luislabmo — Tue, 28 May 2019 21:49:56 GMT

On a watering system the most relevant sensor is perhaps the Soil moisture sensor, which is generally used to determine the watering cycle (or the right time to irrigate the plants). Moisture sensors are of many types; each with their own set of advantages/disadvantages.

For your Arduino project, the best soil moisture sensors may be RF based like the Vegetronix or Capacitive moisture sensors as these won't have exposed metals that will corrode over time. As DAB has suggested try avoiding Resistive moisture sensors; these are cheap but will corrode real quick, one may suggest to use AC and/or stainless steel but the truth is this will just delay the end result (corrosion) and SS in electrolysis is highly toxic (and other metals).

Other sensors that may be incorporated:

UV sensor, helping detect real sun-light (unlike ambient light sensors)
Water level sensors, when using a water tank reservoir (filled manually or with rainwater, etc.) which could help alerting under critical water level conditions and also help preserving the water-pump life
Temperature

UV and Temperature sensors won't help much deciding the watering cycles but may help deciding whether certain type of plant is under ideal conditions to grow/survive

Luis

RE: Arduino-based Smart Watering of Plants

DAB — Mon, 28 Jan 2019 19:27:46 GMT

You should go with a capacitive sensor for the soil moisture sensor.

If you use the sensor shown at 5V, you will find that the sensor contacts will corrode and become erratic.

If you lower the voltage to about 1V, then you prolong the life of the sensor.

Electrolysis starts at about 1.25 volts, so you want to stay below that value.

DAB