USB Serial Port Control Relay Module Sturdy Durable Lightweight USB Relay Module USB Intelligent Control Switch Overcurrent Protection Intelligent Command Control Switch Intelligent Home

Just received it, so I cannot speak to long term durability, but it does what it says. Easy to control (using C# for my purposes), and functions as expected. Solder quality is very good (at least IPC class 2).

A0 01 01 A2 *closes* the normally-open circuit (by activating the relay), and A0 01 00 A1 *opens* the circuit. I think this might just be a language problem - like maybe the seller doesn't get that a closed circuit is an active one, while a closed *port* (for example) is an inactive one.I wish they'd used a protocol that limited itself to printable characters. As it is, you can control this easily enough from a Linux system by creating 'on' and 'off' binary files and copying them to the appropriate /dev/tty file, as long as you've used stty to set the baud rate correctly.

Great little serial-USB relay, Works with Linux Mint 21.3 and with Windows 10.

Works well - has 1 LED for off and 2 LED for on. You can get it working in Windows with a CH340 driver. Linux automatically picks it up in /dev/ttyUSB0. With either c# scripting in windows (Windows picks it up for me as COM5) or a simple echo command in linux with the given hex code you can close or open the relay.

This is a simple device. You plug it into USB and you get a controllable relay rated at 10A up to 250V. Screw terminal for the common, normally open, and normally closed contacts. It shows up as a serial port (/dev/USBx in Linux) and you MUST use 9600 baud. Linux knows about the CH340 chip, but not sure about Windows. But CH340 serial drivers are out there, for sure.There was no manual, but the product page says:Usage Method Step 1: Plug the USB relay module into the computer and install the driver of the CH340 USB to the serial port chip Step 2: Open the serial port debugging software such as STC-ISP and SSCOM32, and select the baud rate of 9600; Send A0 01 01 A2 in hexadecimal (hex) to open the relay; send A0 01 00 A1 in hexadecimal (hex) to close the relay.The A0 is like a start code. The 01 is for the first relay (only one, in this case) 00 or 01 is on/off and the A1/A2 is a checksum. Note that these are HEX values. You can't just type A0 in a terminal program to make this work.That works fine. I used cutecom on Linux to test it (see picture). It was nice that it has an LED that shows it is on and another one that shows if the relay is closed. Nicer if they were different colors, but that's a small thing. What would be a bigger concern if you were doing something that needed high reliability is the thing doesn't answer you. You send your serial data, and presumably, it works. Granted, if you are sitting next to it, you can hear and see it work. But I would have liked to get some acknowledgment back. It would be nice, too, if it had a way to tell you its serial number so if you had a bunch of these on one computer, you could figure out which was which. You can, however, get it to tell you if the relay is ON or OFF by sending an FF. It will reply with "CH1: OFF<CR><LF>" or "CH1: ON<CR><LF>" see second picture.If you search github for LCUS-1 you will find some scripts for Linux/Windows.There are reports of similar devices having failed relays quickly, but these relays are pretty standard and my guess is it is from abuse of the relay. If it does fail, just replace it. The pins are readily exposed and it would be an easy desolder/solder job (see red circle in photo). But my guess is if you use the relay appropriately, it will last as well as any other.

I ordered this USB Serial Port Control Relay Module as a novelty item to play around with, and while it works as described, its limited functionality and outdated design left me questioning its practicality in today’s tech ecosystem.Pros:Basic Functionality: The module performs its primary function—reading serial port commands to toggle the relay on and off—reliably. It uses simple hexadecimal commands for operation, and the onboard LED indicators make it easy to see the relay status at a glance.Sturdy Design: The module feels durable, with overcurrent protection and relay diode freewheeling protection ensuring its longevity.Affordable Price: At under $10, it’s an inexpensive gadget for experimenting or for niche projects.Plug-and-Play (Sort Of): The CH340 USB control chip makes it easy to connect and use without additional drivers, provided you have the right software.Cons:Limited Software Compatibility: The module requires specific serial port debugging software to work properly. Common tools like the Arduino serial monitor won’t work, which significantly limits its ease of use. While the manufacturer mentions compatible software, it’s frustratingly outdated.Very Basic Features: With only two functions—on and off—the module feels incredibly rudimentary compared to modern microcontrollers with robust capabilities.Questionable Practicality: If you’re already using modern tools like Arduino boards, microcontrollers, and cloud-based I/O systems (as I am), this module feels redundant and underwhelming.Unclear Use Cases: While it’s a fun tool for tinkering, its real-world applications are niche. For example, you might use it to build a computer watchdog or novelty automation project, but beyond that, its utility is limited.Outdated Approach: Having to write a dedicated PC program to toggle a single relay feels like taking a step back in time, especially when more versatile solutions are readily available.Conclusion:The USB Serial Port Control Relay Module is a neat toy for tech hobbyists who enjoy tinkering with old-school tools. However, its outdated functionality, limited compatibility, and lack of modern features make it impractical for serious applications. If you’re looking for a simple way to toggle a relay and don’t mind the quirks, this module is worth a try. But if you’re already working with advanced microcontrollers and cloud systems, this might just gather dust in your toolkit.

this relay was very easy to work with, though i wish it took a standard binary instead of hex.