IEIndustrial Automation & EmbeddedB.Tech Capstone, SRM University, June 2023

Advanced Irrigation Automation System (AIAS)

Capstone smart-irrigation system — a NodeMCU RC rover with a submersible pump distributes water across irregular garden areas, while capacitive soil-moisture + DHT11 sensors stream to ThingSpeak for real-time analytics and remote threshold management.

Hardware & Architecture

NodeMCU (ESP8266) + SIM800L GSM/GPRS module for networking.
Capacitive soil-moisture sensor and DHT11 temperature/humidity sensor.
L298N motor controller, 4x DC motors, 5V relay module, submersible mini water pump, 2200mAh LiPo battery.

Key Highlights

RC rover with submersible pump + sprinkler navigates and evenly waters irregularly shaped garden areas.
Continuous soil/temperature/humidity monitoring prevents overwatering and root rot.
Cloud feedback loop streams sensor data to ThingSpeak for visualization, analytics, and remote threshold management.

Images

CAD Model of the AIAS rover and irrigation payload.

FIG-21: Circuit Diagram — Automation System.

Code

aias_rc_control.inoRC Web-Server Motor Controlcpp

#include <ESP8266WiFi.h>
#include <ESP8266WebServer.h>
#include <ArduinoOTA.h>

// Connections for drive Motor FR & BR
int enA = D1;
int in1 = D2;
int in2 = D3;
// Connections for drive Motor FL & BL
int in3 = D4;
int in4 = D5;
int enB = D6;

const int buzPin = D7;     // Buzzer pin
const int ledPin = D8;     // LED pin
const int wifiLedPin = D0; // WiFi connection indicator

String command;    // String to store app command state
int SPEED = 1023;  // Motor speed 330-1023

ESP8266WebServer server(80);

void setup() {
  Serial.begin(115200);
  pinMode(buzPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(wifiLedPin, OUTPUT);
  digitalWrite(wifiLedPin, HIGH);
  pinMode(enA, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
  pinMode(enB, OUTPUT);
  analogWrite(enA, SPEED);
  analogWrite(enB, SPEED);

  // WiFi Connection Logic
  if (WiFi.status() == WL_CONNECTED) {
    digitalWrite(wifiLedPin, LOW);
  } else {
    WiFi.mode(WIFI_AP);
    // AP setup omitted for brevity
    digitalWrite(wifiLedPin, HIGH);
  }
}

void loop() {
  ArduinoOTA.handle();
  server.handleClient();
  command = server.arg("State");

  // Movement Switch Logic
  if (command == "F") Forward();
  else if (command == "B") Backward();
  else if (command == "R") TurnRight();
  else if (command == "L") TurnLeft();
  else if (command == "S") Stop();
  // ... Additional speed and lighting commands
}

aias_thingspeak.inoThingSpeak IoT Data Loggingcpp

#include <ESP8266WiFi.h>
#include <SPI.h>
#include <Wire.h>
#include <DHT.h>

#define DHTPIN D4
DHT dht(DHTPIN, DHT11);

String apiKey = "C251CK6FHOR7PST4";
const char *ssid = "AIAS";
const char *pass = "1234567890";
const char *server = "api.thingspeak.com";

void loop() {
  // Data collection logic omitted for brevity
  if (client.connect(server, 80)) {
    String postStr = apiKey;
    postStr += "&field1=";
    postStr += String(soilmoisturepercent);
    postStr += "&field2=";
    postStr += String(h); // Humidity
    postStr += "&field3=";
    postStr += String(t); // Temperature
    postStr += "&field4=";
    postStr += String(relaypin);
    postStr += "\r\n\r\n";

    client.print("POST /update HTTP/1.1\n");
    client.print("Host: api.thingspeak.com\n");
    client.print("Connection: close\n");
    client.print("X-THINGSPEAKAPIKEY: " + apiKey + "\n");
    client.print("Content-Type: application/x-www-form-urlencoded\n");
    client.print("Content-Length: ");
    client.print(postStr.length());
    client.print("\n\n");
    client.print(postStr);
  }
}