ESP32 Network Discovery Tool

A comprehensive network discovery tool for ESP32 with ethernet connectivity that scans for devices and tests industrial protocol ports.

Features

• Network Device Discovery: Automatically scans the local network for active devices
• Industrial Protocol Support: Tests for common industrial ports including:
  • Port 80 (HTTP)
  • Port 443 (HTTPS)
  • Port 502 (MODBUS TCP)
  • Port 47808 (BACnet)
• Dual Connectivity: Primary ethernet with WiFi backup for reliability
  • Automatic failover when ethernet is disconnected
  • Manual WiFi management and configuration
  • Support for multiple saved WiFi networks with priority
• Web Interface: Complete web-based control panel with:
  • Network configuration (DHCP/Static IP settings)
  • WiFi network management and scanning
  • Customizable scan ranges and target ports
  • Real-time scan progress monitoring
  • CSV export of scan results
  • Responsive design for mobile and desktop
• Triple Interface: Serial commands, web interface, and captive portal
• Persistent Configuration: Network and WiFi settings saved to SPIFFS filesystem

Hardware Requirements

• WT32-ETH01 (recommended) - ESP32-S3 board with built-in ethernet
• Alternative: ESP32-Ethernet-Kit or other ESP32 boards with ethernet capability
• Ethernet cable and network connection
• USB cable for programming and serial communication

WT32-ETH01 Compatibility

This project is optimized for the WT32-ETH01 board, featuring:

• Built-in LAN8720 PHY chip for reliable ethernet
• ESP32-S3 dual-core processor
• Compact design suitable for industrial applications
• Pre-configured pin assignments for plug-and-play operation

See WT32-ETH01_SETUP.md for detailed hardware setup instructions.

Installation

1. Arduino IDE Setup:

   • Install Arduino IDE 2.0 or later
   • Add ESP32 board support: Go to File > Preferences, add this URL to "Additional Board Manager URLs":

     https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
     

   • Go to Tools > Board > Board Manager, search for "esp32" and install

2. Upload Code:

   • Open NetworkDiscovery.ino in Arduino IDE
   • Select your ESP32 board (Tools > Board > ESP32 Arduino > ESP32 Dev Module)
   • Select the correct COM port (Tools > Port)
   • Click Upload

Configuration

The tool is configured through config.h:

// Network timeouts
#define ETH_CONNECTION_TIMEOUT 10000  // 10 seconds
#define SCAN_TIMEOUT 1000            // 1 second per IP
#define PORT_TIMEOUT 3000            // 3 seconds per port

// Scan intervals
#define SCAN_INTERVAL 60000          // 1 minute between scans

// Target ports
const std::vector<int> TARGET_PORTS = {
    80,     // HTTP
    443,    // HTTPS
    502,    // MODBUS TCP
    47808   // BACnet
};

Usage

Web Interface (Recommended)

1. Power on the ESP32 and connect ethernet cable
2. Find the IP address from serial monitor (115200 baud)
3. Open web browser and navigate to the ESP32's IP address
4. Configure network settings (DHCP/Static IP) in the Configuration page
5. Set scan parameters (IP range, target ports) in the Scan page
6. Start scanning and monitor progress in real-time
7. View and export results as CSV from the Results page

Serial Interface

1. Open Serial Monitor (115200 baud) to see output
2. Manual Commands:
   • scan - Start immediate network scan
   • status - Show full system status (ethernet + WiFi)
   • wifi - Show WiFi status only
   • wifi scan - Scan for available WiFi networks
   • wifi connect <ssid> - Connect to WiFi network (prompts for password)
   • wifi disconnect - Disconnect from WiFi
   • wifi toggle - Enable/disable WiFi backup mode
   • ping <ip> - Ping specific IP address
   • port <ip> <port> - Test specific port
   • help - Show all commands

Output Example

ESP32 Network Discovery Tool
============================
Ethernet connected successfully!

Starting network discovery...
=============================
Local IP: 192.168.1.100
Network: 192.168.1.0
Subnet: 255.255.255.0

Found 3 active devices:

Scanning device: 192.168.1.1
  Port  Service      Status
  ----  -----------  ------
  80    HTTP         OPEN
  443   HTTPS        OPEN
  502   MODBUS TCP   CLOSED
  47808 BACnet       CLOSED

Scanning device: 192.168.1.50
  Port  Service      Status
  ----  -----------  ------
  80    HTTP         CLOSED
  443   HTTPS        CLOSED
  502   MODBUS TCP   OPEN
  47808 BACnet       CLOSED

Code Structure

• NetworkDiscovery.ino - Main application file
• config.h - Configuration constants
• network_scanner.h/cpp - Network discovery implementation
• port_scanner.h/cpp - Port scanning implementation

Industrial Protocol Details

MODBUS TCP (Port 502)

• Tests connection and sends basic query packet
• Detects MODBUS-enabled devices like PLCs and HMIs

BACnet (Port 47808)

• Sends Who-Is broadcast request
• Identifies Building Automation devices

HTTP/HTTPS (Ports 80/443)

• Standard web services
• Often used for device web interfaces

WiFi Backup Configuration

1. Access WiFi Settings via web interface at /wifi
2. Scan for networks or manually enter SSID
3. Set network priority (1-10, higher = preferred)
4. Enable backup mode to automatically failover
5. Configure static IP if needed for WiFi networks

Troubleshooting

1. No Network Connection:

   • Check ethernet cable connections first
   • Verify WiFi backup is enabled in settings
   • ESP32 will start Access Point mode if no connections available
   • Connect to "ESP32-NetScanner" AP (password: netscanner123)

2. WiFi Issues:

   • Check WiFi credentials are correct
   • Verify network is in range (check RSSI)
   • Ensure WiFi backup mode is enabled
   • Use serial commands for troubleshooting: wifi status

3. No Devices Found:

   • Confirm ESP32 has network connectivity
   • Check firewall settings on target network
   • Verify target devices are powered on and connected

4. Compilation Errors:

   • Ensure ESP32 board package is installed
   • Install ArduinoJson library via Library Manager
   • Check Arduino IDE version (2.0+ recommended)
   • Verify all files are in same directory

License

This project is open source and available under the MIT License.