Arduino Code

#include <ESP8266WiFi.h>
#include <ThingSpeak.h>

// WiFi Credentials
#define WIFI_SSID "Aditi"
#define WIFI_PASSWORD "adii2004"

// ThingSpeak API
#define CHANNEL_ID 2832905
#define API_KEY "NAHQQXA23U3KG9FM"

// Ultrasonic Sensor Pins
#define TRIG_PIN D5
#define ECHO_PIN D6


#define GREEN_LED_PIN D7
#define RED_LED_PIN D8


WiFiClient client;

void setup() {
    Serial.begin(115200);
    delay(100);

    // Initialize sensor pins
    pinMode(TRIG_PIN, OUTPUT);
    pinMode(ECHO_PIN, INPUT);

    pinMode(GREEN_LED_PIN, OUTPUT);
    pinMode(RED_LED_PIN, OUTPUT);


    // Connect to WiFi
    Serial.print("Connecting to WiFi");
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    while (WiFi.status() != WL_CONNECTED) {
        Serial.print(".");
        delay(500);
    }
    Serial.println("\nConnected to WiFi");

    // Initialize ThingSpeak
    ThingSpeak.begin(client);
}

void loop() {
    float distance = getBinLevel();  // Measure distance

    if (distance == -1) {
        Serial.println("Sensor Error: No echo received.");
    } 
    else 
    {
        float binHeight = 30.0;  
        float fillPercentage = ((binHeight - distance) / binHeight) * 100.0;
        fillPercentage = constrain(fillPercentage, 0, 100);
        
        Serial.print("Distance: ");
        Serial.print(distance);
        Serial.print(" cm | Fill Level: ");
        Serial.print(fillPercentage);
        Serial.println("%");

        int response = ThingSpeak.writeField(CHANNEL_ID, 1, fillPercentage, API_KEY);
        if (response == 200) {
            Serial.println("Data sent to ThingSpeak successfully!");
        } else {
            Serial.print("Error sending data: ");
            Serial.println(response);
        }
        if (fillPercentage > 75) {
        // Dustbin is almost full
        digitalWrite(RED_LED_PIN, HIGH);  // Turn on red LED
        digitalWrite(GREEN_LED_PIN, LOW); // Turn off green LED
    } else {
        // Dustbin is not full
        digitalWrite(GREEN_LED_PIN, HIGH); // Turn on green LED
        digitalWrite(RED_LED_PIN, LOW);    // Turn off red LED
    }
    }

    
    
    delay(15000);
}

// Function to measure bin level using Ultrasonic Sensor
float getBinLevel() {
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);

    long duration = pulseIn(ECHO_PIN, HIGH, 60000); // Increased timeout
    if (duration == 0) {
        return -1; // Return error value
    }

    float distance = duration * 0.034 / 2; // Convert time to distance (cm)
    return distance;
}