ESP32 Virtual UART

A hardware replacement for Windows Virtual Serial Port Emulator (VSPE). An ESP32-S3 USB device that presents multiple virtual COM ports (CDC-ACM) to a host PC, with a web-based visual node editor for routing data and signals between USB ports, physical UARTs, and TCP sockets.

No drivers needed — CDC-ACM is natively supported on Windows, macOS, and Linux.

Features

• 2x USB Virtual COM Ports — CDC-ACM composite device, appears as real COM ports
• 2x Hardware UARTs — Connect physical serial devices
• Routing Engine — Bridge, clone, or merge any combination of ports
• Baud Rate Conversion — Bridge ports running at different speeds
• TCP Streaming — Each port can be a TCP server or client over WiFi
• Signal Line Routing — DTR, RTS, CTS, DSR — route, simulate, or override
• Visual Node Editor — Svelte web GUI with drag-and-drop routing configuration
• Persistent Config — Save/restore routing profiles across reboots
• RGB LED Status — Visual indication of device state and data activity

Hardware

• ESP32-S3-DevKitC (or any ESP32-S3 board with USB-OTG)
• Optional: external UART transceiver for second UART port

Building

Requires ESP-IDF v5.5+.

# Source ESP-IDF environment
. ~/esp/esp-idf/export.sh

# Set target (first time only)
idf.py set-target esp32s3

# Build
idf.py build

# Flash
idf.py -p /dev/ttyUSB0 flash monitor

Architecture

[Windows PC] ──USB──> [ESP32-S3] ──UART1──> [Device A]
                          │       ──UART2──> [Device B]
                          │
                          └──WiFi──> [Web GUI / TCP ports]

Components

Status

Work in progress. Phase 1 (USB CDC + port abstraction) compiles and is ready for hardware testing.

License

MIT