IOT based Soil Moisture Monitoring on Arduino Cloud using Arduino Nano ESP32

Here we are going to build a smart Irrigation project using Arduino NANO ESP 32, DHT22 (temperature and humidity sensor), soil moisture sensor and Arduino cloud (cloud server and dashboard). Realtime data generated by sensors can be monitored from anywhere on Mobile app as well as web dashboard. We can also operate switch from anywhere using mobile app or dashboard  

So now let's start  

So first we know about

 

What is  Arduino NANO ESP 32 Cloud? 

Arduino cloud is cloud-based service provided by Arduino (an open-source electronic platform).it allows us to connect our Arduino devices to internet and manage them remotely  

Some of the key features of Arduino cloud are 

• Remote Monitoring and control 
• IOT Integration 
• Data Storage and Analysis 
• User-friendly interface 
• Security 
• Automation & Alerts 

Table of content 

• • Hardware requirement 

• • Software requirement 

• • Creating thing and dashboard on Arduino cloud 

• • Code and libraries 

• • Circuit diagram 

• • Hardware interfacing  

• • Final working of project 

• Conclusion 

Hardware requirement of this project 

• Arduino NANO ESP32  
• DHT22 (Temperature and Humidity) Sensor 
• Soil Moisture Sensor 
• LED 
• Universal PCB 
• Breadboard 
• Jumper Wire  
• USB data cable 

Software requirement of this project  

•  Arduino IDE 
• Arduino cloud Web 
• Arduino IOT Remote App 
• Arduino create agent for cloud  

 

So, let’s start creating Dashboard 

1. Create/login to Arduino cloud account 
2. Click on Things > CREAT THING 

3. 3. Click on Add variables  

 Name > Humidity >Declaration> CloudRelativeHumidityhumidity Type> Relative humidity > Variable Permission> Read Only >Update Policy> On change 

Create all variable as mentioned below follow same steps shown above  

Name >LED> Declaration> CloudLightlED> Type> Switch> Variable Permission> Read & Write> Update Policy> On change 

Name > Moisture > Declaration> floatmoisture > Type> Floating point number > Variable Permission> Read Only > Update Policy> On change 

Name > Temperature > Declaration> CloudTemperatureSensortemperature Type> Temperature sensor (°c) > Variable Permission> Read Only > Update Policy> On change

4. Once all variables are created Select and configure associate device   

 Here we have Selected Arduino Nano ESP 32 Once device is selected properly 

The device ID and Device Secret key will Displayed we have to Copy it and save It  

After selecting the device, we have to configure the network. (Providing name and credential information of Wi-Fi or Hotspot & Device secrete key) to which we are supposed to connect our Arduino Nano ESP32 

Follow the steps as shown below 

 5.Configure network >Wi-Fi Name>Wi-Fi Password>Device Secrete key 

6. Create a dashboard 

After configuring the network, we create a dashboard where our data will be displayed and Monitored  

Follow the steps  

Click on Dashboards > CREATE DASHBOARD > ADD 

       Select variable; Switch > Link variable       

Things >LED>LINK VARIABLE>DONE 

In this step we create a dashboard icon and connect those icons to variables which we had created earlier 

Follow above steps for linking all the variables mentioned below 

Similarly; ADD>GAUGE> Link variable > Things >Temperature>LINK VARIABLE>DONE 

Similarly; ADD>Percentage> Link variable > Things >Humidity>LINK VARIABLE>DONE 

Similarly; ADD> Percentage > Link variable > Things >Moisture>LINK VARIABLE>DONE 

Similarly; ADD> Chart > Link variable > Things >Temperature>LINK VARIABLE>DONE 

 7.Now Open Sketch in full Editor  

 8.Edit the code according to variables 

9.Download Arduino Create Agent & Connect Arduino Nano ESP32 board in bootloader mode 

10. Select the proper Arduino Board and port 

11. Verify and upload the code 

(NOTE: - Be sure Arduino NANO ESP32 is in bootloader mode, Arduino Create Agent is active &other Arduino IDE   are closed while uploading code otherwise board will throw ERROR) 

CODE: 

#include "arduino_secrets.h" 

/*  

  Sketch generated by the Arduino IoT Cloud Thing "Untitled" 

  https://create.arduino.cc/cloud/things/187bfad8-5590-4e74-8cfc-15e06c1344b5  

 
 

  Arduino IoT Cloud Variables description 

 
 

  The following variables are automatically generated and updated when changes are made to the Thing 

 
 

  float moisture; 

  CloudLight lED; 

  CloudTemperatureSensor temperature; 

  CloudRelativeHumidity humidity; 

 
 

  Variables which are marked as READ/WRITE in the Cloud Thing will also have functions 

  which are called when their values are changed from the Dashboard. 

  These functions are generated with the Thing and added at the end of this sketch. 

*/ 

 
 

#include "thingProperties.h" 

#include <DHT.h>; 

 
 

//Constants 

#define LED_PIN 2 

#define DHTPIN 13  // what pin we're connected to 

#define DHTTYPE DHT22   // DHT 22  (AM2302) 

DHT dht(DHTPIN, DHTTYPE);//// Initialize DHT sensor for normal 16mhz Arduino 

int SENSOR_PIN = A0; // Analog pin defined for soil moisture sensor 

float percentage; 

 
 

float map_low = 4100;   

float map_high = 2700; 

void setup() { 

  // Initialize serial and wait for port to open: 

  Serial.begin(9600); 

   pinMode(LED_PIN, OUTPUT); 

   pinMode(DHTPIN,INPUT); 

   pinMode(SENSOR_PIN,INPUT); 

  // This delay gives the chance to wait for a Serial Monitor without blocking if none is found 

  delay(1500);  

  dht.begin(); 

 
 

  // Defined in thingProperties.h 

  initProperties(); 

 
 

  // Connect to Arduino IoT Cloud 

  ArduinoCloud.begin(ArduinoIoTPreferredConnection); 

   

  /* 

     The following function allows you to obtain more information 

     related to the state of network and IoT Cloud connection and errors 

     the higher number the more granular information you’ll get. 

     The default is 0 (only errors). 

     Maximum is 4 

 */ 

  setDebugMessageLevel(2); 

  ArduinoCloud.printDebugInfo(); 

} 

 
 

void loop() { 

  ArduinoCloud.update(); 

  // Your code here  

   float m = analogRead(SENSOR_PIN); 

    moisture = m; 

 
 

  Serial.print("Raw: "); 

  Serial.print(moisture); 

 
 

  percentage = map(moisture, map_low, map_high, 0, 100); 

  moisture = percentage; 

   if (percentage > 50) { 

    digitalWrite(LED_PIN, LOW); 

    Serial.print("Water Pump is OFF "); 

  } else { 

    digitalWrite(LED_PIN, HIGH); 

    Serial.print("Water Pump is ON"); 

  } 

  Serial.print(" | Percentage: "); 

  Serial.print(percentage); 

  Serial.println("%"); 

 
 

  delay(1000); 

  float h = dht.readHumidity(); 

  float t = dht.readTemperature(); 

  temperature = t; 

  humidity = h; 

  if (isnan(humidity) || isnan(temperature)) { 

    Serial.println("Failed to read from DHT sensor!"); 

  }else{ 

  Serial.print(F("Temprature- "));Serial.print(t); 

  Serial.print(F("Humidity- "));Serial.print(h); 

  delay(2000); 

  } 

   

   

} 

/* 

  Since LED is READ_WRITE variable, onLEDChange() is 

  executed every time a new value is received from IoT Cloud. 

*/ 

void onLEDChange()  { 

  if (lED == 0 ) 

  { 

    digitalWrite(LED_PIN, LOW); 

  } 

  else 

  { 

    digitalWrite(LED_PIN, HIGH); 

  } 

  // Add your code here to act upon LED change 

} 

Libraries: 

If your using Arduino cloud for uploading code Arduino cloud agent will download all necessary libraries automatically 

If not  

Download  

Arduino_ESP_32_OTA from Library manager of Arduino IDE

If you want to upload code from Arduino IDE Download it from Arduino cloud sketch 

Add network credential properly with device secret key. 

(NOTE: Don’t forget to pause Arduino create agent else IDE can throw ERROR) 

Circuit diagram: 

Interface the components as per circuit diagram 

DHT22 sensor 

DHT22 Sensor pins	Arduino NANO ESP32 PINS
+VE	3.3v
-Ve	GND
OUT	D13

Soil Moisture sensor 

Soil moisture sensor	Arduino NANO ESP32 PINS
VCC	3.3V
GND	GND
A0	A0

AND connect LED to D2 pin 

Hardware interfacing 

We have made the connection on PCB as shown in circuit diagram 

Assembled all the components on PCB and provided supply to Arduino Nano ESP32 board 

As code is already uploaded, we just need to verify all connections are proper and our Wi-Fi is operational and Arduino Nano ESP32 board is connected to Wi-Fi & Cloud dashboard  

Demonstration /how it works 

Sensor is in moist soil moisture is optimum in soil, so LED is OFF 

Other Climatic factors like temperature and humidity are   measured are displayed as shown on mobile screen 

Sensor is out of moist soil no moisture is sensed by sensor so LED is ON, and it will remain ON until moisture reaches optimum level  

Conclusion: 

In this way we have created a project for Monitoring Temperature, Humidity and soil moisture Using Arduino Nano ESP 32 & Arduino cloud for smart irrigation. By using the power of cloud technology this project offers wide range of benefits, from improving water usage efficiency to real-time monitoring & control capabilities which can empower farmers to make data-driven decision, leading to increase in crop yield. 

For more interesting projects check out this link https://youtu.be/Ah0RZSD0n5M and our YouTube channel

Tags : Arduino Cloud , Arduino nano ESP32 , humidity sensor , sensors , temperature sensor