IoT-Based Aquaponics System Using ESP32 & KiwisIoT

Project Description

This project combines fish farming and plant growing. ESP32 monitors water temperature, pH and water level. Sensor readings are displayed on the KiwisIoT dashboard using Wi-Fi.

CONNECTIONS:

Project Implementation Steps

Step 1: Assemble the fish tank and plant-growing bed.

Step 2: Install the water pump and connect the water circulation pipes.

Step 3: Connect the DS18B20, pH and ultrasonic sensors to the ESP32.

Step 4: Connect the relay module and water pump.

Step 5: Install Arduino IDE and the required libraries.

Step 6: Upload the ESP32 program.

Step 7: Configure the Wi-Fi and KiwisIoT MQTT credentials.

Step 8: Create the KiwisIoT dashboard and configure its widgets.

Step 9: Test each sensor and verify the readings.

Step 10: Test automatic pump control using a water-only setup.

#include <WiFi.h>
#include <PubSubClient.h>
#include <OneWire.h>
#include <DallasTemperature.h>

// WiFi configuration b
const char* ssid = "YOUR_WIFI_NAME";
const char* password = "YOUR_WIFI_PASSWORD";

// KiwisIoT MQTT configuration
const char* mqtt_server = "YOUR_MQTT_BROKER";
const int mqtt_port = 1883;
const char* mqtt_user = "YOUR_USERNAME";
const char* mqtt_password = "YOUR_PASSWORD";

// MQTT topics
const char* tempTopic = "aqua/temp";
const char* phTopic = "aqua/ph";
const char* levelTopic = "aqua/level";
const char* pumpTopic = "aqua/pump";

// ESP32 pins
#define TEMP_PIN 4
#define PH_PIN 34
#define TRIG_PIN 5
#define ECHO_PIN 18
#define RELAY_PIN 26

#define PUMP_ON LOW
#define PUMP_OFF HIGH

// Tank configuration
float tankHeight = 30.0;
float minLevel = 25.0;

// pH calibration values
float voltagePH7 = 2.50;
float voltagePH4 = 3.00;

OneWire oneWire(TEMP_PIN);
DallasTemperature tempSensor(&oneWire);

WiFiClient espClient;
PubSubClient client(espClient);

bool pumpStatus = false;

// Connect to WiFi
void connectWiFi() {
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("WiFi Connected!");
}

// Connect to MQTT
void connectMQTT() {
  while (!client.connected()) {
    if (client.connect("ESP32_Aquaponics",
                       mqtt_user,
                       mqtt_password)) {
      Serial.println("MQTT Connected!");
    } else {
      Serial.println("MQTT Connection Failed!");
      delay(3000);
    }
  }
}

// Read temperature
float getTemperature() {
  tempSensor.requestTemperatures();
  return tempSensor.getTempCByIndex(0);
}

// Read pH
float getPH() {
  int raw = analogRead(PH_PIN);
  float voltage = raw * 3.3 / 4095.0;

  float slope =
      (7.0 - 4.0) / (voltagePH7 - voltagePH4);

  return 7.0 + (voltage - voltagePH7) * slope;
}

// Read water level
float getWaterLevel() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH, 30000);

  if (duration == 0) return -1;

  float distance = duration * 0.0343 / 2.0;

  float level =
      ((tankHeight - distance) / tankHeight) * 100.0;

  return constrain(level, 0, 100);
}

// Pump control
void controlPump(float level) {
  if (level < 0 || level < minLevel) {
    pumpStatus = false;
  } else {
    pumpStatus = true;
  }

  digitalWrite(
      RELAY_PIN,
      pumpStatus ? PUMP_ON : PUMP_OFF
  );
}

// Send data to KiwisIoT
void sendData(const char* topic, float value) {
  char message[20];

  snprintf(message, sizeof(message), "%.2f", value);

  client.publish(topic, message);
}

// Setup
void setup() {
  Serial.begin(115200);

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, PUMP_OFF);

  analogReadResolution(12);

  tempSensor.begin();

  connectWiFi();

  client.setServer(mqtt_server, mqtt_port);
}

// Main loop
void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    connectWiFi();
  }

  if (!client.connected()) {
    connectMQTT();
  }

  client.loop();

  float temperature = getTemperature();
  float ph = getPH();
  float waterLevel = getWaterLevel();

  controlPump(waterLevel);

  Serial.println("AQUAPONICS MONITORING");

  Serial.print("Temperature: ");
  Serial.println(temperature);

  Serial.print("pH: ");
  Serial.println(ph);

  Serial.print("Water Level: ");
  Serial.println(waterLevel);

  Serial.print("Pump Status: ");
  Serial.println(pumpStatus ? "ON" : "OFF");

  if (temperature != DEVICE_DISCONNECTED_C) {
    sendData(tempTopic, temperature);
  }

  if (ph >= 0 && ph <= 14) {
    sendData(phTopic, ph);
  }

  if (waterLevel >= 0) {
    sendData(levelTopic, waterLevel);
  }

  sendData(pumpTopic, pumpStatus ? 1 : 0);

  delay(5000);
}

KiwisIoT Dashboard Configuration

KiwisIoT is used to monitor sensor readings remotely.

Dashboard Setup

Visit https://www.kiwisiot.com/.Create an account or sign in.Create a new panel named Smart Aquaponics System.Register or configure your ESP32 device.Obtain the MQTT connection details.Configure the telemetry topics.Add the required dashboard widgets

Conclusion

The IoT-Based Aquaponics System Using ESP32 with KiwisIoT provides a simple and effective approach to smart agriculture. It monitors important water parameters and automatically controls water circulation based on water-level conditions.

By integrating ESP32, sensors, Wi-Fi and the KiwisIoT dashboard, users can monitor their aquaponics system remotely. This project demonstrates how IoT technology can improve monitoring and automation in sustainable fish farming and plant cultivation.

Project Outcome: A smart aquaponics prototype that integrates water monitoring, automatic pump control and remote IoT dashboard visualization.