🔐 IoT Smart Lock & Room Automation — ESP32-S3

A fully integrated IoT system combining smart door lock access control with automated room appliance management, built on the ESP32-S3-N16R8.

Cost: ~4,500 PKR | vs. 15,000+ PKR for commercial solutions

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📋 Table of Contents

• Overview
• Hardware
• Pin Reference
• Features
• Blynk Setup
• Arduino IDE Settings
• Libraries Required
• How It Works
• Keypad Controls
• RGB LED Status
• Repo Structure
• License

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Overview

This system replaces both a standalone smart lock and a room automation hub with a single ESP32-S3-N16R8 micro-controller. The ESP32-S3's built-in Wi-Fi eliminates the need for a separate Wi-Fi module, reducing hardware complexity and cost.

Authentication methods: 4×4 keypad (local) + Blynk mobile app (remote)
Automation trigger: PIR motion sensor — detects when the room is empty and alerts if appliances are left on
Appliance control: 4-channel relay module (light, fan, AC, extra)

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Hardware

Component	Details
Micro-controller	ESP32-S3-N16R8 (16MB Flash, 8MB OPI PSRAM, dual USB-C)
Keypad	4×4 matrix keypad
Motion Sensor	PIR sensor (2-second software debounce)
Door Lock	Servo motor — 0° = locked, 90° = unlocked
Relay Module	4-channel, active LOW
Buzzer	KY-012 active buzzer
Status LED	Built-in RGB NeoPixel on GPIO 48
Programming	CH343P USB-to-Serial chip via USB-C

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Pin Reference

GPIO	Component
4	Relay 1 — Light
5	Relay 2 — Fan
6	KY-012 Buzzer
7	PIR Motion Sensor
8	Servo Motor (PWM)
15	Relay 3 — AC
16	Relay 4 — Extra
17, 18, 21, 38	Keypad Rows
39, 40, 41, 42	Keypad Columns
48	Built-in RGB NeoPixel LED

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Features

1. Dual authentication — Keypad password entry + Blynk app remote control
2. Smart exit detection — Monitors motion + door lock status together
3. Energy alerts — Notifies if appliances are on 30 seconds after you leave
4. Remote control — Door lock + 4 appliances via Blynk mobile app
5. Security alerts — Push notifications for unauthorized access attempts
6. Non-blocking buzzer — Timer-based audio feedback (no blocking delay())
7. RGB status LED — Color-coded system state using the onboard NeoPixel

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Blynk Setup

Virtual Pin	Function
V0	Lock / Unlock toggle
V1	Lock status display
V2	Motion status display
V3	Relay 1 (Light)
V4	Relay 2 (Fan)
V5	Relay 3 (AC)
V6	Relay 4 (Extra)
V7	Turn OFF all appliances
V8	System log / notification feed

Blynk Events to configure in your template:

Event Name	Description
door_locked	Door was locked
door_unlocked	Door was unlocked
unauthorized_access	Wrong password entered
appliances_on	Appliances left on after exit

⚠️ Add your own BLYNK_TEMPLATE_ID, BLYNK_TEMPLATE_NAME, and BLYNK_AUTH_TOKEN in the .ino file before uploading.

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Arduino IDE Settings

Setting	Value
Board	ESP32S3 Dev Module
Flash Size	16MB (128Mb)
Partition Scheme	16M Flash (3MB APP/9.9MB FATFS)
PSRAM	OPI PSRAM
USB CDC On Boot	Enabled
Upload Speed	921600
Port	COM port (CH343P chip)

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Libraries Required

Install all via Arduino IDE Library Manager:

• Blynk by Volodymyr Shymanskyy
• Keypad by Mark Stanley, Alexander Brevig
• ESP32Servo by Kevin Harrington
• Adafruit NeoPixel by Adafruit

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How It Works

1. On boot, all relays initialize HIGH (OFF). Door locked. RGB = red.
2. Enter password on keypad then press # to unlock.
3. On correct password: servo rotates to 90°, RGB turns green, Blynk notified.
4. PIR sensor tracks motion in the room.
5. When door is locked + no motion detected for 30 seconds:
   • System checks which relays are still ON
   • Sends Blynk push notification listing active appliances
   • RGB turns yellow
6. User can turn off appliances remotely via Blynk.

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Keypad Controls

Key	Action
0–9	Enter password digits
#	Confirm / Submit password
*	Clear current input
A	Manually lock the door

Default password: 1111 (change PASSWORD constant in code)

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RGB LED Status

Color	Meaning
🔴 Red	Door locked
🟢 Green	Door unlocked
🔵 Blue	Motion detected
🟡 Yellow	Appliances left on (warning)
🟣 Purple	Wrong password entered

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Repo Structure

IoT-Smart-Lock-Room-Automation/
│
├── code/
│   └── EspCode.ino              # Main ESP32-S3 firmware
│
├── docs/
│   └── Iot based Smart door lock and dynamic room automation system.pdf                 # IEEE-format review paper (LaTeX)
│
├── simulation/
│   └── ICT_Project.pkt          # Cisco Packet Tracer simulation
│
├── images/
│   ├── Cisco_Packet_Tracer_Circuit.png
│   ├── appendixA_components.png
│   ├── appendixB_flowchart.png
│   └── appendixC_circuit.png
|   └── appendixD_blynk.png.png
│
├── LICENSE
└── README.md

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License

This project is licensed under the MIT License — see LICENSE for details.
Free to use, modify, and share. Credit appreciated.

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Built by Reyan Kashif