SOIL MOISTURE LEVEL MONITORING IOT DEVICE FOR SMART
IRRIGATION
ER-DIAGRAM
START
Check moisture level and
temperature
If
Moisture<value
NO
YES
Start Irrigation
Intialize the pump
STOP
Fig 1. ER DIAGRAM FOR SMART IRRIGATION SYSTEM
The ER Diagram of smart irrigation system is illustrated in Fig.1. Once the system is
plugged ON it initializes all components and sets the soil moisture level to its default value.
Then the soil moisture sensor connected to the Arduino UNO senses the moisture level in the
soil. The Arduino IDE software connected to the Arduino UNO via USB module will receive
the values from Arduino and display them on the serial port monitor. Arduino UNO
processes the received moisture content data from the sensor and decides about the need of
watering the field. The dry soil leads to the water flowing into the field and if the soil is wet
the water flow stops. Eventually, this system ensures that the moisture content and
availability of water in the field are thoroughly maintained. Soil moisture sensors measure the
water content in soil. Moisture in the soil is animportant component in the atmospheric water
cycle.Sensor module outputs a highlevel of resistance when the soil moisture is low. It has
both digital and analogoutputs. Digital output is simple to use, but it is not as accurate as
analog output basedon moisture level motor gets turn on/off automatically.
CIRCUIT DIAGRAM
•
Connect the rely module to the Arduino uno.Connect the VCC of the relay module to
the 5v pin of the Arduino and connect the ground of the relay to the ground of
Arduino. Now connect the relay signal pin to any digital pin of Arduino except pin
13.
•
The next step is to connect the soil moisture sensor with the Arduino. Connect the
VCC and gnd of the sensor to the 5volt and ground pin of the Arduino. The analogue
output of the sensor connects to any analogue pin of the Arduino, here I’ve connected
it to pin A0 (According to the program).
•
Finally, connect the pump to the relay module. A relay module has 3 connection
points which are common, normally closed, and normally open. We have to connect
the pump positive to common and connect the normally open pin to the positive of the
battery. You have to select the battery as per your pump. The next step is to connect
the ground of the pump to the ground of the Arduino and finally, connect the small
hose to the water pump.
•
Now connect the battery to the circuit and if the pump starts working then the circuit
is okay. Now upload the code to Arduino.