MicroLock

ESP32-based smart lock firmware that exposes a small HTTP JSON API over the local network. Built with PlatformIO and the Arduino framework.

Hardware

• Board: ESP32 DOIT DevKit V1
• Lock pin: GPIO 25 (drives relay / solenoid — HIGH = locked, LOW = unlocked)
• Buzzer pin: GPIO 26 (feedback beeps)

Features

• HTTP JSON API on port 1212 (default recommended)
• Token-based authentication (token sent in request body)
• Wi-Fi Station mode (connects to an existing network)
• Automatic fallback to Access Point mode if STA connection fails within 15 s
• Audible beep feedback on lock/unlock

Getting Started

Prerequisites

• PlatformIO (CLI or VS Code extension)
• An ESP32 DOIT DevKit V1 (or compatible)

Configure

Edit the constants at the top of src/main.cpp before flashing:

const char* WIFI_SSID     = "<your-wifi-ssid>";
const char* WIFI_PASSWORD = "<your-wifi-password>";
const char* AP_SSID       = "<your-ssid>";
const char* AP_PASSWORD   = "<ap-password>";
const char* AUTH_TOKEN    = "<your-secret-token>";

Build & Flash

pio run                 # build
pio run -t upload       # flash
pio device monitor      # serial monitor @ 115200

The device prints its IP to the serial monitor after connecting:

STA IP: 192.168.1.23

API

Full frontend integration guide is in docs/implementation.md.

Quick reference:

Method	Path	Auth	Description
GET	/	no	Device info / ping
POST	/lock	yes	Lock the device
POST	/unlock	yes	Unlock the device
POST	/status	yes	Get current state

Authenticated requests send the token in the JSON body:

{ "token": "your-secret-token" }

Project Layout

.
├── docs/               # integration docs
├── include/            # project headers
├── lib/                # private libraries
├── src/main.cpp        # firmware entry point
├── test/               # unit tests
└── platformio.ini      # PlatformIO config

Security Notes

• Traffic is plain HTTP — only use on trusted Wi-Fi networks.
• The auth token is hard-coded in firmware. Change it before deploying and do not commit production tokens.
• There is no rate limiting in firmware — the client should debounce lock/unlock actions.