Circuit Documentation

Summary

This circuit is designed to measure depth, humidity, and temperature using an HC-SR04 ultrasonic sensor and a DHT11 sensor. If the measured depth is less than 5 cm, a piezo buzzer will ring. All measurements are displayed on a 16x2 I2C LCD. The circuit is controlled by an Arduino UNO microcontroller.

Component List

1. DHT11

   • Description: Humidity and Temperature Sensor
   • Pins: DATA, GND, VCC

2. 16x2 I2C LCD

   • Description: LCD Display with I2C Interface
   • Pins: GND, VCC, SDA, SCL

3. Piezo Buzzer

   • Description: Sound Buzzer
   • Pins: pin 1, pin 2

4. HC-SR04 Ultrasonic Sensor

   • Description: Ultrasonic Distance Sensor
   • Pins: VCC, TRIG, ECHO, GND

5. Arduino UNO

   • Description: Microcontroller Board
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

Wiring Details

DHT11

• VCC: Connected to Arduino UNO 5V
• GND: Connected to Arduino UNO GND
• DATA: Connected to Arduino UNO D3

16x2 I2C LCD

• GND: Connected to Arduino UNO GND
• VCC: Connected to Arduino UNO 5V
• SDA: Connected to Arduino UNO A4
• SCL: Connected to Arduino UNO A5

Piezo Buzzer

• pin 1: Connected to Arduino UNO D9
• pin 2: Connected to Arduino UNO GND

HC-SR04 Ultrasonic Sensor

• VCC: Connected to Arduino UNO 5V
• GND: Connected to Arduino UNO GND
• TRIG: Connected to Arduino UNO D11
• ECHO: Connected to Arduino UNO D10

Arduino UNO

• 5V: Supplies power to DHT11, HC-SR04, and 16x2 I2C LCD
• GND: Common ground for all components
• A4: I2C SDA line for 16x2 I2C LCD
• A5: I2C SCL line for 16x2 I2C LCD
• D3: Data line for DHT11
• D9: Control line for Piezo Buzzer
• D11: Trigger line for HC-SR04
• D10: Echo line for HC-SR04

Code Documentation

/*
 * This Arduino sketch measures depth, humidity, and temperature using an
 * HC-SR04 ultrasonic sensor and a DHT11 sensor. If the measured depth is
 * less than 5 cm, a piezo buzzer will ring. All measurements are displayed
 * on a 16x2 I2C LCD.
 */

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

// Pin definitions
#define TRIG_PIN 11
#define ECHO_PIN 10
#define DHT_PIN 3
#define BUZZER_PIN 9

// Constants
#define DHT_TYPE DHT11
#define DEPTH_THRESHOLD 5.0

// Initialize sensors and LCD
DHT dht(DHT_PIN, DHT_TYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  // Initialize sensors and LCD
  dht.begin();
  lcd.begin();
  lcd.backlight();
  // Initialize pin modes
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  // Measure depth
  float depth = measureDepth();
  // Measure humidity and temperature
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  // Display measurements on LCD
  lcd.setCursor(0, 0);
  lcd.print("Depth: ");
  lcd.print(depth);
  lcd.print(" cm");
  lcd.setCursor(0, 1);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print(" C Hum: ");
  lcd.print(humidity);
  lcd.print(" %");
  // Check depth and ring buzzer if necessary
  if (depth < DEPTH_THRESHOLD) {
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }
  // Wait before next measurement
  delay(2000);
}

float measureDepth() {
  // Send trigger pulse
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  // Measure echo pulse duration
  long duration = pulseIn(ECHO_PIN, HIGH);
  // Calculate depth in cm
  float depth = duration * 0.034 / 2;
  return depth;
}

This code initializes the sensors and LCD, measures depth, humidity, and temperature, and displays the measurements on the LCD. If the depth is less than 5 cm, the piezo buzzer will ring. The measurements are updated every 2 seconds.