---
product_id: 2076922
title: "USB 4 Channel Relay Automation (5V)"
brand: "sainsmart"
price: "€ 43.22"
currency: EUR
in_stock: true
reviews_count: 3
url: https://www.desertcart.de/products/2076922-usb-4-channel-relay-automation-5v
store_origin: DE
region: Germany
---

# USB 4 Channel Relay Automation (5V)

**Brand:** sainsmart
**Price:** € 43.22
**Availability:** ✅ In Stock

## Quick Answers

- **What is this?** USB 4 Channel Relay Automation (5V) by sainsmart
- **How much does it cost?** € 43.22 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.de](https://www.desertcart.de/products/2076922-usb-4-channel-relay-automation-5v)

## Best For

- sainsmart enthusiasts

## Why This Product

- Trusted sainsmart brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Description

SainSmart USB 4 Channel Relay Automation (5V)

## Product Details

- **Connector Type:** 5-pin Header Connector
- **Contact Material:** Silver
- **Contact Type:** Normally Open
- **Mounting Type:** PCB Mount
- **Brand:** SainSmart

## Images

![USB 4 Channel Relay Automation (5V) - Image 1](https://m.media-amazon.com/images/I/41KP-+1plmL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great little device!! And Python-able! (see below)
*by M***M on July 1, 2016*

I'm generally not big on writing online reviews, but I felt like I needed to share my experience (and maybe offer some small help to get folks started?). For myself, I was looking for a way to automate control of a fan and a hard drive via program or script (and hopefully in Python!). After some mild growing pains, this device proved extremely useful and super convenient!The device has an FTDI controller as a brain - these chips have been around for years and generally are auto-detected by Windows...mine came up as a "USB Serial Port", and for my purposes, that was all I needed. There *are* special FTD2XX drivers available online for Windows (and documentation available as well - just search "ftd2xx"), but I personally haven't had any need to install them.For Python, I used a publicly available module called "ftd2xx 1.0" (Google [ ftd2xx python ]).Unzip the package, find [ setup.py ], open a command prompt there, and run [ python setup.py install ].Now, there are many wonderful and glorious ways to control/ping the FTDI, all of which can be read in the FTD2XX documentation discussed above - but I *only* cared about turning the relays on and on off. So here's just a simplified example Python script that I used to get started (Amazon doesn't allow text formatting, apparently - please remove the [indent]s below and replace with actual indents ^_^):================================================import ftd2xx as ftimport timeON = TrueOFF = FalseRELAY_0 = 0x01 # Farthest from the USB connectorRELAY_1 = 0x02RELAY_2 = 0x04RELAY_3 = 0x08 # Closest to the USB Connectordevice = ft.open(0) # Opens the device, if it's connecteddevice.setBitMode(0xFF, 0x01) # IMPORTANT TO HAVE: This sets up the FTDI device as "Bit Bang" mode.def setRelay(relay, state):[indent] relayStates = device.getBitMode() # Get the current state of the relays[indent] if state == ON:[indent] device.write( chr(relayStates | relay) ) # Turn on relay(s) (without messing with the others)[indent] # The .write() method requires a CHARACTER, so we[indent] # type-cast our selected state INT to a chr()[indent] elif state == OFF:[indent] device.write( chr(relayStates & ~relay) ) # Turn off relay(s) (again without killing the others)setRelay( RELAY_0, ON ) # Turn Relay 0 ONtime.sleep(.5) # Wait 0.5 secondssetRelay( RELAY_1 | RELAY_3, ON ) # Turn Relays 1 and 3 ONtime.sleep(.5) # Wait 0.5 secondssetRelay( RELAY_1, OFF ) # Turn Relay 1 OFFtime.sleep(.3) # Wait 0.3 secondssetRelay( 0x0F, ON ) # No need to use globals...EVERYTHING ONtime.sleep(.3) # Wait 0.3 secondssetRelay( 0x0A, OFF ) # Turn Relay 0 and 2 OFFtime.sleep(.3) # Wait 0.3 secondssetRelay( 0x05, OFF ) # Turn Relay 1 and 3 OFFHope this helps!!!

### ⭐⭐⭐⭐⭐ SainSmart USB 4 Channel Relay Board is pretty smart
*by S***T on March 4, 2018*

This review is based on the experiences that I had buying/using this product. I am also going to respond to some of the other reviewers that had some "constructive" criticism had of the product.1. First - the price and form factor are perfect. If I had to duplicate this product using other means (i.e. DAQ Board/Relay Board) -- I am going to spend $100+ for the same functionality. This product simplifies everything and its priced at less than $20.2. Second -- the command set is simple. I know it is "interesting" when the product is not well documented (or even provided the wrong information). I was unable to get the VCP mode to work but the Bit Bang mode worked perfectly. The advantage of the Bit Bang DLL is that you can get additional information (part number, serial number). I spent roughly 4 to 6 hours working on my software subroutines which is basically a one time (up front) "cost" of figuring out a new board.3. Finally - there were some reviewers complaining that the board does not include the capability of handle inductive kick (i.e. diodes) in the case where you are hooked up to a motor or something. In my case, I am driving some simple lights so I don't want to have the mfg include parts that I do not require or need.In summary - this is a nice product. I have bought six and used two. This product is now part of my permanent toolkit for projects.

### ⭐⭐⭐⭐ Handy board but poor documentation
*by M***E on August 9, 2019*

I read most of the reviews before ordering this device to use as part of a custom temperature-control system. I have a fair amount of experience with serial devices and machine programming. I expected getting this up and running would be fairly straightforward but it ended up taking a few hours. Here's what I now know:1) I got the 5v version. The relays can be powered from the USB, but this requires a standard PC-type jumper (not included). As-shipped, I guess you would need to connect a 5v external power supply. If you don't have jumpers laying around, order some.2) I was intending to operate this device via the virtual COM port on my PC as some reviewers reported (though I noticed that some reviewers reported trouble doing this...). It wasn't clear to me after reading other reviews but it seems that this device will only respond to serial commands (relays mapped to bits in a single byte, not as documented in the description download) AFTER it has been place in the so-called "bit bang mode" by a prior call to the SetBitMode() function in the FTD2XX.DLL (after each power-up), so you'll have to load/learn that interface to use serial/VCP (or first run the Relay Manager utility in the description download - it apparently leaves the chip in this mode). After putting in the effort to do this, I decided to just use the DLL for everything and not serial. There doesn't seem to be any way to put the FTDI chip in bit bang mode by sending commands to the virtual COM port interface (as far as I could find) - not convenient...3) My program was in 64-bit VBA. FTDI has a 64-bit PC driver but all the examples I downloaded from their website were 32-bit (had 32-bit Declares). I had to modify the Declares for all of the functions I needed (add PtrSafe and handles should be LongLong).

## Frequently Bought Together

- SainSmart USB 4 Channel Relay Automation (5V)
- SainSmart USB Eight Channel Relay Board for Automation - 12 V

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*Product available on Desertcart Germany*
*Store origin: DE*
*Last updated: 2026-02-05*