Project Documentation

Arduino Nano ESP32-Based Aquaponics Monitoring System with Battery Power

Circuit Documentation

Summary

This document provides a detailed overview of an aquaponics monitoring and control system. The system utilizes various sensors to monitor water quality parameters such as temperature, pH, Total Dissolved Solids (TDS), and Dissolved Oxygen (DO). An Arduino Nano ESP32 microcontroller processes the sensor data and controls a water pump via a relay based on the readings.

Component List

AHT10
- Description: Temperature and Humidity Sensor
- Pins: Vcc, Gnd, SCL, SDA
Buck Converter
- Description: DC-DC Step-Down Converter
- Pins: IN+, IN-, OUT+, OUT-
Lipo Battery 2200mAH 30c
- Description: Rechargeable Lithium Polymer Battery
- Pins: VCC, GND
1-Channel Relay (5V 10A)
- Description: Relay Module for Switching High Power Devices
- Pins: NC, signal, C, power, NO, ground
PH Meter
- Description: pH Sensor for Measuring Acidity/Alkalinity
- Pins: Signal, VCC, GND
Water Pump
- Description: Pump for Water Circulation
- Pins: positive, negative
Arduino Nano ESP32
- Description: Microcontroller for Processing Sensor Data and Controlling Actuators
- Pins: D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, GND, RST, RX0, TX1, D13, 3.3V, B0, A0, A1, A2, A3, A4, A5, A6, A7, VBUS, B1, VIN
TDS Sensor
- Description: Total Dissolved Solids Sensor for Measuring Water Quality
- Pins: AI, GND, 5V
Temperature Sensor
- Description: Temperature Sensor for Measuring Water Temperature
- Pins: Temp GND Black, Temp VDD Red, Temp DQ Data Yellow
DO Sensor
- Description: Dissolved Oxygen Sensor for Measuring Oxygen Levels in Water
- Pins: Vcc, Gnd, Out

Wiring Details

AHT10

Vcc: Connected to Buck Converter OUT+
Gnd: Connected to Buck Converter OUT-
SCL: Connected to Arduino Nano ESP32 A5
SDA: Connected to Arduino Nano ESP32 A4

Buck Converter

IN+: Connected to Lipo Battery VCC and 1-Channel Relay C
IN-: Connected to Lipo Battery GND and 1-Channel Relay ground
OUT+: Connected to AHT10 Vcc, TDS Sensor 5V, 1-Channel Relay power, Temperature Sensor Temp VDD Red, PH Meter VCC, DO Sensor Vcc
OUT-: Connected to AHT10 Gnd, TDS Sensor GND, Temperature Sensor Temp GND Black, PH Meter GND, DO Sensor Gnd

Lipo Battery 2200mAH 30c

VCC: Connected to Buck Converter IN+ and 1-Channel Relay C
GND: Connected to Buck Converter IN- and 1-Channel Relay ground

1-Channel Relay (5V 10A)

NC: Not connected
signal: Connected to Arduino Nano ESP32 D8
C: Connected to Lipo Battery VCC and Buck Converter IN+
power: Connected to Buck Converter OUT+
NO: Connected to Water Pump positive
ground: Connected to Lipo Battery GND, Water Pump negative, and Buck Converter IN-

PH Meter

Signal: Connected to Arduino Nano ESP32 A3
VCC: Connected to Buck Converter OUT+
GND: Connected to Buck Converter OUT-

Water Pump

positive: Connected to 1-Channel Relay NO
negative: Connected to 1-Channel Relay ground

Arduino Nano ESP32

D8: Connected to 1-Channel Relay signal
D5: Connected to Temperature Sensor Temp DQ Data Yellow
A0: Connected to TDS Sensor AI
A1: Connected to DO Sensor Out
A3: Connected to PH Meter Signal
A4: Connected to AHT10 SDA
A5: Connected to AHT10 SCL

TDS Sensor

AI: Connected to Arduino Nano ESP32 A0
GND: Connected to Buck Converter OUT-
5V: Connected to Buck Converter OUT+

Temperature Sensor

Temp GND Black: Connected to Buck Converter OUT-
Temp VDD Red: Connected to Buck Converter OUT+
Temp DQ Data Yellow: Connected to Arduino Nano ESP32 D5

DO Sensor

Vcc: Connected to Buck Converter OUT+
Gnd: Connected to Buck Converter OUT-
Out: Connected to Arduino Nano ESP32 A1

Code Documentation

#include <Wire.h>
#include <OneWire.h>
#include <DallasTemperature.h>
#include <AHT10.h>
#include <DFRobot_ESP_PH.h>
#include <DFRobot_DO.h> // Added dissolved oxygen sensor library

// Pin Definitions
#define TDS_SENSOR_PIN A0
#define PH_SENSOR_PIN A3
#define DS18B20_PIN 5
#define RELAY_PIN 8
#define ONE_WIRE_BUS DS18B20_PIN
#define DO_SENSOR_PIN A1 // Added pin for dissolved oxygen sensor
#define SCL_PIN A5 // Typical SCL pin for I2C
#define SDA_PIN A4 // Typical SDA pin for I2C

// Sensor Objects
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature tempSensor(&oneWire);
AHT10 aht10;
DFRobot_ESP_PH ph;
DFRobot_DO do_sensor; // Dissolved oxygen sensor object
float tdsSensorValue = 0;
float phValue = 0;
float doValue = 0; // Dissolved oxygen value

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

    // Initialize I2C with specific SCL and SDA pins
    Wire.begin(SDA_PIN, SCL_PIN);

    // Initialize Sensors
    tempSensor.begin();

    // AHT10 Initialization
    if (!aht10.begin())
    {
        Serial.println("AHT10 not found. Check wiring!");
    }

    // PH Sensor Initialization
    ph.begin();

    // Dissolved Oxygen Sensor Initialization
    do_sensor.begin();

    // Relay Setup
    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, LOW);
}

void loop()
{
    // Read Temperature Sensors
    tempSensor.requestTemperatures();
    float waterTemp = tempSensor.getTempCByIndex(0);

    // Read AHT10 (Humidity and Air Temperature)
    float humidity = aht10.readHumidity();
    float airTemp = aht10.readTemperature();

    // Read TDS Sensor
    tdsSensorValue = readTDSSensor();

    // Read PH Sensor
    phValue = readPHSensor();

    // Read Dissolved Oxygen Sensor
    doValue = readDOSensor(waterTemp);

    // Print Sensor Readings
    Serial.println("--- Aquaponics Sensor Readings ---");
    Serial.print("Water Temperature: ");
    Serial.print(waterTemp);
    Serial.println(" °C");

    Serial.print("Air Temperature: ");
    Serial.print(airTemp);
    Serial.println(" °C");

    Serial.print("Humidity: ");
    Serial.print(humidity);
    Serial.println(" %");

    Serial.print("TDS Value: ");
    Serial.print(tdsSensorValue);
    Serial.println(" ppm");

    Serial.print("PH Value: ");
    Serial.print(phValue);
    Serial.println("");

    Serial.print("Dissolved Oxygen: ");
    Serial.print(doValue);
    Serial.println(" mg/L");

    // Control Relay (example: turn on if water temp is below 20°C)
    if (waterTemp < 20.0)
    {
        digitalWrite(RELAY_PIN, HIGH);
    }
    else
    {
        digitalWrite(RELAY_PIN, LOW);
    }

    delay(5000); // Read sensors every 5 seconds
}

float readTDSSensor()
{
    int sensorValue = analogRead(TDS_SENSOR_PIN);
    float voltage = sensorValue * (3.3 / 4095.0);
    float tdsValue = (133.42 * voltage * voltage * voltage - 255.86 * voltage * voltage + 857.39 * voltage) * 0.5;
    return tdsValue;
}

float readPHSensor()
{
    static unsigned long samplingTime = millis();
    static unsigned long printTime = millis();
    static float pHValue, voltage;

    if (millis