🧠 Smart Dustbin (Blynk IoT Cloud Version)

🎯 Objective of This Lesson

Students will learn:

• What is Cloud IoT

• How to connect ESP32 to Blynk Cloud

• How to create Datastreams

• How to design Dashboard

• How to monitor dustbin remotely

Now you can monitor dustbin from anywhere 🌍

🌐 What is Blynk IoT?

Blynk is a cloud IoT platform that allows:

• Remote monitoring

• Mobile dashboard control

• Cloud data storage

• Real-time updates

🧾 Step 1 – Blynk Account Setup

1. Go to: https://blynk.cloud

2. Create account

3. Click Create Template

4. Choose:

   • Hardware → ESP32

   • Connection → WiFi

5. Save template

🧾 Step 2 – Create Datastreams

Inside Template → Datastreams → Create:

🔹 Virtual Pin Setup

Save all.

🧾 Step 3 – Create Device

1. Go to Devices

2. Click “New Device”

3. From Template

4. Copy:

• Auth Token

• Template ID

• Template Name

You will paste this into code.

🧾 Step 4 – Design Dashboard

Open Web Dashboard or Mobile App.

Add Widgets:

1️⃣ Label → V0 → Hand Status
2️⃣ Gauge → V1 → Garbage Distance
3️⃣ Label → V2 → Dustbin Status

Now your IoT dashboard is ready.

🔌 Hardware Connections (Same as Before)

Ultrasonic 1 → GPIO 5, 18
Ultrasonic 2 → GPIO 17, 16
Servo → GPIO 13

🧾 Complete ESP32 Blynk Code (Copy–Paste Ready)

Replace WiFi and Blynk credentials before uploading.

#define BLYNK_TEMPLATE_ID "YOUR_TEMPLATE_ID"
#define BLYNK_TEMPLATE_NAME "SmartDustbin"
#define BLYNK_AUTH_TOKEN "YOUR_AUTH_TOKEN"

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <ESP32Servo.h>

// -------- WiFi Credentials --------
char ssid[] = "YOUR_WIFI_NAME";
char pass[] = "YOUR_WIFI_PASSWORD";

// -------- Pin Definitions --------
#define TRIG1 5
#define ECHO1 18

#define TRIG2 17
#define ECHO2 16

#define SERVO_PIN 13

Servo myServo;
BlynkTimer timer;

long duration;
float distanceHand;
float distanceGarbage;

// -------- Distance Function --------
float getDistance(int trigPin, int echoPin) {

digitalWrite(trigPin, LOW);
delayMicroseconds(2);

digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

float distance = duration * 0.034 / 2;

return distance;
}

// -------- Send Data to Blynk --------
void sendData() {

// Hand Detection
distanceHand = getDistance(TRIG1, ECHO1);

if (distanceHand > 0 && distanceHand < 20) {
myServo.write(90);
delay(3000);
myServo.write(0);
Blynk.virtualWrite(V0, "Hand Detected - Lid Opened");
}

// Garbage Level
distanceGarbage = getDistance(TRIG2, ECHO2);

Blynk.virtualWrite(V1, distanceGarbage);

if (distanceGarbage > 0 && distanceGarbage < 8) {
Blynk.virtualWrite(V2, "Dustbin is FULL");
} else {
Blynk.virtualWrite(V2, "Dustbin is NOT Full");
}
}

void setup() {

Serial.begin(115200);

pinMode(TRIG1, OUTPUT);
pinMode(ECHO1, INPUT);

pinMode(TRIG2, OUTPUT);
pinMode(ECHO2, INPUT);

myServo.attach(SERVO_PIN);
myServo.write(0);

Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

timer.setInterval(2000L, sendData);
}

void loop() {

Blynk.run();
timer.run();
}

🧠 Code Explanation (Step-by-Step)

1️⃣ Blynk Credentials

These connect ESP32 to your cloud dashboard.

2️⃣ Blynk.begin()

Connects ESP32 to:

• WiFi

• Blynk Cloud Server

3️⃣ Virtual Write

Sends data to virtual pin V1.

Dashboard widget connected to V1 will show value.

4️⃣ Timer Function

Runs sendData() every 2 seconds.

Prevents blocking.

📊 Dashboard Output Example

V0 → Hand Detected – Lid Opened
V1 → 6.5 cm
V2 → Dustbin is FULL

🎓 Learning Outcomes

We now understand:

• Cloud IoT Architecture

• Virtual Pins

• Real-time monitoring

• Template & Device concept

• Professional IoT structure