💧 Smart Water Management System (Serial Monitor Version)

Using:

• ESP32

• Water Level Sensor (Analog)

• Single Channel Relay

• DC Water Pump

This version will work in:

• 🔄 AUTO Mode (Automatic motor control)

• 🎮 MANUAL Mode (Control via Serial commands)

🔌 Connections

1️⃣ Water Level Sensor (Analog Mode)

2️⃣ Relay Module

⚠ Relay controls pump externally (12V line).

💻 COMPLETE FINAL CODE (Serial Monitor Version)

Copy & paste:

// Pin Definitions
#define WATER_SENSOR 34
#define RELAY_PIN 26

int waterValue = 0;
bool autoMode = true; // Default AUTO mode
bool motorState = false; // Motor OFF initially

// Set your tank thresholds (adjust after testing)
int lowLevel = 1000; 
int fullLevel = 3000;

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

pinMode(RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, HIGH); // Motor OFF (Relay active LOW)

Serial.println("=== Smart Water Management System ===");
Serial.println("Commands:");
Serial.println("AUTO -> Enable Auto Mode");
Serial.println("MANUAL -> Enable Manual Mode");
Serial.println("ON -> Motor ON (Manual Mode)");
Serial.println("OFF -> Motor OFF (Manual Mode)");
Serial.println("------------------------------------");
}

void loop() {

// Read water sensor
waterValue = analogRead(WATER_SENSOR);

Serial.print("Water Level Value: ");
Serial.println(waterValue);

// Check Serial Commands
if (Serial.available()) {
String command = Serial.readStringUntil('\n');
command.trim();

if (command.equalsIgnoreCase("AUTO")) {
autoMode = true;
Serial.println("Switched to AUTO Mode");
}
else if (command.equalsIgnoreCase("MANUAL")) {
autoMode = false;
Serial.println("Switched to MANUAL Mode");
}
else if (command.equalsIgnoreCase("ON") && !autoMode) {
turnMotorOn();
}
else if (command.equalsIgnoreCase("OFF") && !autoMode) {
turnMotorOff();
}
}

// AUTO Mode Logic
if (autoMode) {

if (waterValue < lowLevel && !motorState) {
Serial.println("Water LOW -> Motor ON");
turnMotorOn();
}

if (waterValue > fullLevel && motorState) {
Serial.println("Tank FULL -> Motor OFF");
turnMotorOff();
Serial.println("WARNING: Tank Full!");
}
}

delay(2000);
}

void turnMotorOn() {
digitalWrite(RELAY_PIN, LOW); // Active LOW relay
motorState = true;
Serial.println("Motor is ON");
}

void turnMotorOff() {
digitalWrite(RELAY_PIN, HIGH);
motorState = false;
Serial.println("Motor is OFF");
}

🧠 CODE EXPLANATION (Clear & Simple)

1️⃣ Pin Definitions

• GPIO 34 → Water sensor analog input

• GPIO 26 → Relay control

2️⃣ Threshold Values

These values decide:

• Below 1000 → Tank Empty

• Above 3000 → Tank Full

⚠ You must calibrate these using Serial Monitor readings.

3️⃣ Modes

• true → Auto mode

• false → Manual mode

4️⃣ Serial Commands

Available commands:

5️⃣ Auto Mode Logic

If water is LOW → Motor ON

If tank FULL → Motor OFF + Warning

6️⃣ Relay Logic

Most relay modules are Active LOW:

• LOW → Motor ON

• HIGH → Motor OFF

📟 Example Serial Monitor Output

🎯 What Students Learn From This Version

• Analog sensor reading

• Threshold comparison

• Auto vs Manual logic

• Relay control

• Real-time monitoring

• Embedded automation

📌 Important Calibration Step

1. Upload code

2. Observe waterValue when tank empty

3. Observe waterValue when tank full

4. Adjust:

🚀 Next Upgrade Options

Shiv 👑 You can now upgrade to:

• 📊 Percentage level calculation

• 📱 Bluetooth version

• 🌐 WiFi Dashboard version

• ☁ Blynk IoT version

• 📈 Water level graph

• 🔔 Buzzer alert system