AWS IoT Core with ESP32: Build a Real Android App

Course Overview

This course helps beginners learn how to connect microcontrollers like ESP32 to AWS IoT Core, exchange data using MQTT, and build real-world smart IoT applications.

You will start from absolute basics—no prior AWS, cloud, or embedded experience is required. Step by step, you will build a complete IoT system covering hardware, cloud, and mobile application integration.

By the end of this course, you will be able to:

• Securely connect ESP32 devices to AWS IoT Core

• Publish and subscribe to MQTT topics

• Control real hardware from AWS IoT Core and an Android app

Target Audience

• Beginners in IoT or AWS

• Engineering students

• Software developers exploring cloud and hardware integration

• Makers and electronics hobbyists

• Android developers interested in IoT applications

Course Structure

SECTION 1: Introduction to IoT and AWS IoT Core

• What is IoT? Real-world use cases

• Introduction to AWS IoT Core

• Why AWS for IoT projects

• Course overview and required tools

SECTION 2: Setting Up the Environment

• Create an AWS Free Tier account safely

• Install Arduino IDE for ESP32

• Install drivers and ESP32 board packages

• Test ESP32 with a basic Blink sketch

SECTION 3: AWS IoT Core Basics

• Understanding AWS IoT Core architecture (Thing, Certificate, Policy)

• Registering a new Thing

• Creating and attaching certificates and policies

• Understanding IoT endpoints

SECTION 4: Connect ESP32 to AWS IoT Core

• Install PubSubClient and WiFiClientSecure libraries

• Connect ESP32 to Wi-Fi and AWS IoT Core

• Publish MQTT messages from ESP32 to AWS

SECTION 5: Bi-Directional Communication

• Subscribe ESP32 to AWS topics

• Send commands from AWS IoT Core to ESP32 (LED ON/OFF)

• Use AWS IoT MQTT Test Client

SECTION 6: Real-World Project #1 – Smart Home Switch

• Project overview and demo

• Hardware wiring and code explanation

• Deploy and test the project

SECTION 7: Android App for Smart Home Control

• Build an Android app using AWS IoT Core SDK

• Control an ESP32-based smart switch from a mobile app

• Complete an end-to-end IoT ecosystem

Section Outcome

Students will build an Android application that communicates with AWS IoT Core to control a real ESP32-based smart home switch (Light ON/OFF).

This completes a full end-to-end IoT solution:

ESP32 Hardware → AWS IoT Core → Android Mobile App

Section 8: Production-Grade Authentication & Authorization Architecture

This section moves beyond basic IoT connectivity and dives into real-world security architecture using Amazon Cognito.

You’ll gain a deep understanding of:

• How User Pools authenticate users and issue JWT tokens

• How Identity Pools exchange those tokens for temporary AWS credentials

• How IAM roles enforce least-privilege access

• How mobile and web apps securely access AWS services

• How Cognito integrates with AWS IoT Core in production

We also clarify the critical difference between user authentication and device authentication, ensuring you understand when to use Cognito versus X.509 certificates in IoT architectures.

This section equips you with the architectural knowledge required to design secure, scalable, and production-ready IoT systems — not just demo projects.

Section 9: MQTT Protocol Explained (From Basics to AWS IoT Core)

Learn the MQTT protocol in depth, the backbone of modern IoT communication.

This section explains how publish/subscribe works, how topics are structured, how QoS affects reliability, and how AWS IoT Core securely manages MQTT traffic at scale. You’ll gain a clear mental model of how messages flow between devices, cloud, and applications.

Section 10: Security & Scalability Best Practices for IoT Applications

Move beyond demos and learn industry best practices for building secure and scalable IoT solutions.

This section covers secure access patterns, least-privilege IAM usage, scalable topic design, device lifecycle management, and cost-aware architecture decisions—helping you build applications that are ready for real production environments.