Soil Moisture Sensor Arduino
In this post, I will show you how you can use a moisture sensor with arduino to measure the moisture/water content of a place. This can be used to sense rainfall in smart weather sensors, water content of the soil for smart irrigation projects etc. Arduino can be easily programmed to work with this moisture sensor, can be easily programmed and put it in action in no time. Wiki:This Arduino Analog capacitive soil Moisture Sensor measures soil moisture levels by capacitive sensing, rather than resistive sensing like other types of moisture sensor. It is made of a corrosion resistant material giving it a long service life.
Soil moisture sensor is a sensor used to measure the amount of water in the soil at any particular point in time. Instead of the old gravimetric method of measuring soil water content, the soil moisture sensor measures the volumetric water content indirectly by using other properties associated with the soil, like its electrical resistance to measure the soil humidity.The soil humidity sensor used for this tutorial was acquired from banggood.com at a cheap price of less than $2. Some of the features of this sensor are listed below. Operating voltage: 3.3V5V. Adjustable sensitivity (shown in blue digital potentiometer adjustment).
Dual output mode, analog output more accurate. A fixed bolt hole for easy installation. With power indicator (red) and digital switching output indicator (green). Having LM393 comparator chip, stable.
Panel PCB Dimension: 3cm x 1.5cm. Soil Probe Dimension: 6cm x 2cm. Cable Length: 21cm. Soil moisture Sensor ProbeThe probe of the sensor which is shown in the image below has two large exposed pads.The more water in the soil the better the electrical conductivity between the pads as a result of lower resistance. When the soil is dry, the resistance in the soil becomes higher and conductivity between this pads reduces.
This helps the sensor determine the water level in the soil.To make the reading of the soil humidity easy, we will be using the Nokia 5110 LCD display alongside with the Arduino.At the end of this tutorial, we would have learned how to use the soil humidity sensor to read the soil humidity and display the humidity on an LCD. This project is a good building block for the development of an automatic irrigation system. Required Parts and Where to BuyThe following parts are needed to build this project and they can be bought via the link in front of them. Soil Moisture Sensor:. Cheap Arduino Uno:. Nokia 5110 LCD:. Small Breadboard:.
Jumper wires:. Wires. To test the project, upload the code to your Arduino board and set up the system, inserting the sensor into a dry soil as shown in the image below.When the Arduino is powered, the since the soil is dry and the sensor does not detect any moisture, as seen in the image above, the percentage value will reduce to as low as 1%. If we decide to add a little amount of water to the soil so it becomes moist, as shown in the image below, the percentage soil humidity increases.As mentioned at the beginning of this tutorial, it is just to show us how the sensor works.
Soil Moisture Sensor Arduino Coding
I will be making a tutorial on a more useful application of this sensor very soon. If you have comments and suggestions on cool projects you will like me to build with this sensor, kindly drop a comment under the comment section of this post.Thanks for reading and watching. Don’t forget to subscribe so you don’t miss subsequent tutorials. ——————–SUBSCRIBE ON YOUTUBE——————–Never miss a video.
Most soil moisture sensors are designed to estimate soil volumetric water content based on the dielectric constant (soil bulk permittivity) of the soil. The dielectric constant can be thought of as the soil's ability to transmit electricity. The dielectric constant of soil increases as the water content of the soil increases. This response is due to the fact that the dielectric constant of water is much larger than the other soil components, including air. Thus, measurement of the dielectric constant gives a predictable estimation of water content. I hope you do not mind me making a few remarks on your project: 1. The sensor is a resistance sensor, not a capacitive.
So it does not measure the dielectric constant but simply the resistance of the soil between the two 'legs' If it were a capacitive sensor it would need to be isolated from the soil and you could not simply measure it with an analog port. As you are reading it with an analog port, the module itself (the module in between the sensor and your arduino) becomes redundant and just uses power for nothing. The Analog pin on the module, is directly connected to the sensor, bypassing the electronics on that module. Better connect the sensor directly to the analog port on your arduino. As the sensor will be fed current oon a continous bas, it will corrode due to electrolysis very rapidly. One can use an Arduinopin rather than a continous 5Volt to feed the sensor and switch it off in between readings.
That will seriously enhance the time your sensor will last. I hope you do not mind me making these essential remarks.