Circuit Documentation

Summary

The circuit is designed to monitor water levels and provide alerts in case of flooding. It consists of an ultrasonic sensor for measuring water levels, a float switch for detecting water presence, an I2C LCD screen for displaying information, a GSM module for sending SMS alerts, and a NodeMCU V3 ESP8266 microcontroller for controlling the system.

Component List

I2C LCD 16x2 Screen

• Description: A 16x2 character LCD display that uses the I2C communication protocol.
• Pins: SCL, SDA, VCC (5V), GND, VDD, VO, RS, RW, E, D0-D7, BLA, BLK

SIM800L GSM Module

• Description: A GSM/GPRS module that allows the microcontroller to communicate over a mobile network.
• Pins: 5V, GND, VDD, SIM_TXD, SIM_RXD, RST

HC-SR04 Ultrasonic Sensor

• Description: An ultrasonic ranging module that provides 2cm to 400cm non-contact measurement functionality.
• Pins: VCC, TRIG, ECHO, GND

Float Switch

• Description: A switch that is triggered by the rising or falling level of liquid.
• Pins: GND, Digital Pin

NodeMCU V3 ESP8266

• Description: An open-source Lua based firmware for the ESP8266 WiFi SOC from Espressif and uses the Lua scripting language.
• Pins: A0, GND, VU, S3-S0, SK, 3V3, EN, RST, Vin, D0-D8, RX, TX

Wiring Details

I2C LCD 16x2 Screen

• SCL: Connected to D1 of NodeMCU V3 ESP8266
• SDA: Connected to D2 of NodeMCU V3 ESP8266
• VCC (5V): Connected to Vin of NodeMCU V3 ESP8266
• GND: Connected to GND of NodeMCU V3 ESP8266

SIM800L GSM Module

• 5V: Connected to Vin of NodeMCU V3 ESP8266
• GND: Connected to GND of NodeMCU V3 ESP8266
• SIM_TXD: Connected to D4 of NodeMCU V3 ESP8266
• SIM_RXD: Connected to D3 of NodeMCU V3 ESP8266

HC-SR04 Ultrasonic Sensor

• VCC: Connected to 3V3 of NodeMCU V3 ESP8266
• TRIG: Connected to D5 of NodeMCU V3 ESP8266
• ECHO: Connected to D6 of NodeMCU V3 ESP8266
• GND: Connected to GND of NodeMCU V3 ESP8266

Float Switch

• Digital Pin: Connected to A0 of NodeMCU V3 ESP8266
• GND: Connected to GND of NodeMCU V3 ESP8266

Documented Code

NodeMCU V3 ESP8266

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <NewPing.h>
#include <SoftwareSerial.h>

// LCD Display
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Ultrasonic Sensor
#define TRIGGER_PIN 12  // NodeMCU V3 ESP8266 D5
#define ECHO_PIN 11    // NodeMCU V3 ESP8266 D6
#define MAX_DISTANCE 200
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

// Float Sensor
#define FLOAT_SENSOR_PIN 10  // NodeMCU V3 ESP8266 A0

// GSM Module
SoftwareSerial gsmSerial(8, 9);  // NodeMCU V3 ESP8266 D4 (TX), D3 (RX)
#define GSM_BAUDRATE 9600

// Thresholds
#define FLOOD_THRESHOLD 50  // Example threshold in cm

// Phone Numbers
String phoneNumbers[] = { "+639568667239" };  // Example phone numbers

void setup() {
  // Initialize LCD Display
  lcd.begin(16, 2);
  lcd.backlight();

  // Initialize GSM Module
  gsmSerial.begin(GSM_BAUDRATE);
  delay(2000);               // Give GSM module time to initialize
  sendCommand("AT");         // Check communication
  sendCommand("AT+CMGF=1");  // Set SMS text mode

  // Display Initialization Message
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Flood Monitoring");
  lcd.setCursor(0, 1);
  lcd.print("System");

  delay(3000);  // Display initialization message for 3 seconds
}

void loop() {
  // Read Ultrasonic Sensor
  unsigned int distance = sonar.ping_cm();

  // Read Float Sensor
  int floatSensorValue = digitalRead(FLOAT_SENSOR_PIN);

  // Calculate Flood Level
  int floodLevel = distance;

  // Update LCD Display
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Water Level: ");
  lcd.print(floodLevel);
  lcd.print("cm");

  // Check Flood Threshold
  if (floodLevel > FLOOD_THRESHOLD && floatSensorValue == HIGH) {
    // Send Alert SMS
    sendAlertSMS(floodLevel);
  }

  delay(500);  // Delay for stability
}

void sendAlertSMS(int floodLevel) {
  String message = "Flood Alert! Water level is ";
  message += floodLevel;
  message += "cm. Take necessary actions.";

  for (int i = 0; i < sizeof(phoneNumbers) / sizeof(phoneNumbers[0]); i++) {
    sendCommand("AT+CMGS=\"" + phoneNumbers[i] + "\"");
    delay(1000);
    sendCommand(message);
    delay(100);
    sendCommand((String) char(26));  // End AT command with a CTRL+Z
    delay(1000);
  }
}

void sendCommand(String command) {
  gsmSerial.println(command);
  delay(1000);
  while (gsmSerial.available()) {
    gsmSerial.read();  // Clear the buffer
  }
}

This code is responsible for initializing the components, reading sensor data, updating the LCD display, and sending SMS alerts when the flood level exceeds a predefined threshold. The sendAlertSMS function constructs the alert message and sends it to the predefined phone numbers using the GSM module. The sendCommand function is a utility to send AT commands to the GSM module and handle the response.