LCUS USB Relay Module 1/2/4/8 Channel Smart Home Switch

LCUS USB Relay Module — Intelligent Control Switch for Smart Home & Automation

Take full command of your smart home, automation projects, or Arduino/STM setups with the Jessinie LCUS USB Relay Module. Available in 1, 2, 4, and 8-channel configurations (LCUS-1, LCUS-2, LCUS-4, LCUS-8), this compact and reliable module lets you control AC and DC loads directly from your computer via USB serial commands — no extra hardware required.

Whether you're a hobbyist, engineer, or smart-home enthusiast, the LCUS relay module offers plug-and-play simplicity with robust performance and multi-channel flexibility. Made in Mainland China.

Why Choose the LCUS USB Relay Module?

• Multiple Channel Options: Choose from 1, 2, 4, or 8-channel versions to match your project's exact needs.
• CH340 USB-to-Serial Chip: Industry-standard CH340 chip ensures stable, reliable USB communication with your PC.
• High-Performance Microcontroller: Onboard controller chip provides fast, accurate command execution.
• High Switching Capacity: Relays rated at 10A / 250V AC and 10A / 30V DC — suitable for a wide range of AC and DC loads.
• Long Relay Lifespan: Each relay supports up to 10 million continuous switching cycles.
• Built-In Protection: Features overcurrent protection and relay diode freewheeling protection for safe, dependable operation.
• LED Status Indicators: Onboard power LED and individual relay status LEDs for at-a-glance monitoring.
• Flexible Power Supply: Supports both USB power and external 5V DC power supply (switchable via toggle).
• Compatible with Arduino, STM & More: Ideal for DIY electronics, home automation, industrial control, and maker projects.

Technical Specifications

USB Switch Command Protocol

Commands are sent as 4-byte HEX packets via your serial terminal at baud rate 9600:

• Byte 1: Start identifier (default: 0xA0)
• Byte 2: Channel address (e.g., 0x01 = Channel 1)
• Byte 3: Operation (0x01 = ON, 0x00 = OFF)
• Byte 4: Checksum

Example — Channel 1:
Turn ON: A0 01 01 A2
Turn OFF: A0 01 00 A1

Quick Setup Guide

1. Plug the USB relay module into your computer.
2. Install the CH340 USB-to-serial driver (required on first use).
3. Open serial debugging software (e.g., SSCOM32 or STC-ISP).
4. Set baud rate to 9600 and select HEX Send mode.
5. Send the appropriate HEX command to toggle your relay channel ON or OFF.
6. Use the "Auto Cycle Send" feature for automated switching routines.

Power Supply Tip: If using external power mode ("Ext_P"), always connect the external 5V DC supply — without it, the relay LED will light but the relay will not activate.

Relay Status Check (LCUS-4 / LCUS-8)

Send FF in HEX format to query the current status of all relay channels. The module will return a readable status string, e.g.:
CH1:ON CH2:ON CH3:OFF CH4:OFF

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Frequently Asked Questions

Q: What is the difference between the LCUS-1, LCUS-2, LCUS-4, and LCUS-8 USB relay modules?

A: The LCUS-1, LCUS-2, LCUS-4, and LCUS-8 USB relay modules differ only in the number of independently controllable relay channels — 1, 2, 4, and 8 channels respectively. All share the same CH340 USB-to-serial chip, the same HEX command protocol at 9600 baud, and the same 10A relay rating. Choose the channel count that matches the number of devices or circuits you need to control.

Q: What software do I need to control the LCUS USB relay module from my computer?

A: You need to first install the CH340 USB-to-serial driver on your computer. After that, any serial terminal software capable of sending HEX commands works — popular options include SSCOM32 and STC-ISP. Simply set the baud rate to 9600, switch to HEX mode, and send the 4-byte command packet to control each relay channel.

Q: Can the LCUS USB relay module be used with Arduino or other microcontrollers?

A: Yes! The LCUS USB relay module is fully compatible with Arduino, STM32, Raspberry Pi, and any platform that supports USB serial communication. You can send HEX commands programmatically from your microcontroller or custom software application to automate relay switching for smart home, industrial, or DIY electronics projects.

Q: What loads can the LCUS relay module switch?

A: The onboard relays are rated at 10A / 250V AC and 10A / 30V DC, making them suitable for controlling a wide variety of household and low-voltage DC loads including lights, fans, pumps, solenoids, and other appliances within the rated current and voltage limits.

Q: Do I need an external power supply for the LCUS relay module?

A: For the LCUS-1 and most single-channel applications, USB power from your computer is typically sufficient. The LCUS-4 and LCUS-8 modules include a toggle switch to select between USB power ("Usb_P") and an external 5V DC power supply ("Ext_P"). If you select external power mode, you must connect the 5V supply — otherwise the relays will not operate even if the status LEDs are lit.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.