Relay Deck

A cross-platform desktop application built with Tauri v2, Rust, Vue 3, and TypeScript for controlling Modbus RTU relay devices. s

Features

• Automatic relay detection
• Connect / disconnect relay devices
• Real-time relay control
• Sequence execution
• Blink animations
• Event logging
• Cross-platform support
• Modern desktop UI

Technology Stack

Frontend

• Vue 3
• TypeScript
• Vite

Backend

• Rust
• Tokio
• Tauri v2

Communication

• Modbus RTU
• Serial Port
• RS485

Architecture

┌──────────────┐
│ Vue Frontend │
└──────┬───────┘
       │ invoke()
       ▼
┌──────────────┐
│    Tauri     │
└──────┬───────┘
       │
       ▼
┌──────────────┐
│ Rust Backend │
└──────┬───────┘
       │
       ▼
┌──────────────┐
│ Modbus RTU   │
└──────┬───────┘
       │
       ▼
┌──────────────┐
│ Relay Device │
└──────────────┘

Hardware Used

Waveshare Modbus RTU Relay

• 8 Relay Channels
• Modbus RTU Protocol
• RS485 Communication

USB to RS485 Adapter

Used to connect the desktop application to the relay controller.

Demo Device

USB-powered LED bulb connected through relay outputs.

Example Command Flow

Vue

await invoke("relay_set", {
    channel: 1,
    on: true,
});

Rust

#[tauri::command]
pub async fn relay_set(
    state: State<'_, RelayState>,
    channel: u16,
    on: bool,
) -> Result<(), String> {
    set_coil(conn, channel, on).await
}

Running

Requirements

• Rust
• Node.js
• pnpm

Install

pnpm install

Development

pnpm tauri dev

Build

pnpm tauri build

Motivation

This project was created to explore how modern web technologies can be combined with Rust to build native desktop applications capable of interacting with real hardware.

The application demonstrates:

• Frontend ↔ Rust communication
• Native desktop integrations
• Modbus RTU communication
• Hardware control using Tauri

Bonus Project

A companion Ratatui-based terminal application was created using the same concepts and relay communication patterns:

➡️ relay-deck-tui