LCD 3xLED Buzzer Ultrasonic Sensor Trash Detector

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

// Initialize LCD (16x2)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// LED Pins
#define GREEN_LED 8
#define YELLOW_LED 9
#define RED_LED 10

// Ultrasonic Sensor Pins
#define TRIG_PIN 11
#define ECHO_PIN 12

// Buzzer Pin
#define BUZZER_PIN 13

// Bin Height (in cm)
const int BIN_HEIGHT = 30; // Adjust based on the actual bin height

void setup() {
  // Initialize Serial Monitor
  Serial.begin(9600);

  // Initialize LCD
  lcd.init();
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Trash Bin Level");

  // Set LED pins as OUTPUT
  pinMode(GREEN_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);

  // Set Buzzer pin as OUTPUT
  pinMode(BUZZER_PIN, OUTPUT);

  // Set Ultrasonic pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  delay(1000);
}

void loop() {
  // Measure distance using Ultrasonic sensor
  int distance = getUltrasonicDistance();
  int trashLevel = BIN_HEIGHT - distance; // Calculate filled level
  trashLevel = max(0, min(trashLevel, BIN_HEIGHT)); // Clamp value between 0 and BIN_HEIGHT

  // Calculate percentage of trash
  int percentage = map(trashLevel, 0, BIN_HEIGHT, 0, 100);

  // Display level and percentage on LCD
  lcd.setCursor(0, 0);
  lcd.print("Level: ");
  lcd.print(trashLevel);
  lcd.print(" cm          ");

  lcd.setCursor(0, 1);
  lcd.print("Full: ");
  lcd.print(percentage);
  lcd.print("%           ");

  // Update LED indicators
  updateLEDs(percentage);

  // Control Buzzer
  if (percentage >= 80) {
    //digitalWrite(BUZZER_PIN, HIGH); // Turn buzzer ON
    tone(BUZZER_PIN, 1000, 500); // Beep at 1000Hz for 500ms
  } else {
    digitalWrite(BUZZER_PIN, LOW);  // Turn buzzer OFF
  }

  // Print details to Serial Monitor (for debugging)
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.print(" cm, Level: ");
  Serial.print(trashLevel);
  Serial.print(" cm, Full: ");
  Serial.print(percentage);
  Serial.println("%");

  delay(500); // Update every 500ms
}

// Function to measure distance using HC-SR04 with averaging
int getUltrasonicDistance() {
  long totalDistance = 0;

  // Take 10 readings and sum them up
  for (int i = 0; i < 10; i++) {
    // Send trigger pulse
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);

    // Measure the duration of the echo pulse
    long duration = pulseIn(ECHO_PIN, HIGH);

    // Calculate distance (in cm)
    int distance = duration * 0.034 / 2;

    totalDistance += distance;
    delay(50); // Small delay between readings to stabilize
  }

  // Calculate the average
  int averageDistance = totalDistance / 10;

  return averageDistance;
}


// Function to update LED indicators based on trash percentage
void updateLEDs(int percentage) {
  if (percentage < 10) {
    // Low level: Green LED ON
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(RED_LED, LOW);
  } else if (percentage < 50) {
    // Low level: Green LED ON
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(RED_LED, LOW);
  } else if (percentage < 80) {
    // Medium level: Yellow LED ON
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(YELLOW_LED, HIGH);
    digitalWrite(RED_LED, LOW);
  } else {
    // High level: Red LED ON
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(YELLOW_LED, HIGH);
    digitalWrite(RED_LED, HIGH);
  }
}