--- product_id: 4103638 title: "SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM" brand: "sainsmart" price: "R858" currency: ZAR in_stock: true reviews_count: 8 category: "Sain Smart" url: https://www.desertcart.co.za/products/4103638-sainsmart-usb-4-channel-dc-12v-relay-module-automation-arduino store_origin: ZA region: South Africa --- # SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM **Brand:** sainsmart **Price:** R858 **Availability:** ✅ In Stock ## Quick Answers - **What is this?** SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM by sainsmart - **How much does it cost?** R858 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.za](https://www.desertcart.co.za/products/4103638-sainsmart-usb-4-channel-dc-12v-relay-module-automation-arduino) ## 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 Overview: This USB Relay Controller/Data Acquisition Module allows computer controlled switching of external devices as well as full bi-directional communication with the external world (ideal for Data Acquisition applications) using the USB port of your computer. The controller is very flexible and can be used in many custom applications including weather stations as well as temperature monitoring, logging and control as it can be easily connected to temperature and other types of sensors.Communication Parameters: 8 Data, 1 Stop, No Parity Baud rate : 9600 Drivers are available to work with the following operating systems: Windows Server 2008 R2, Windows 7, Windows 7 x64, Windows Server 2008, Windows Server 2008 x64, Windows Vista, Windows Vista x64, Windows Server 2003, Windows Server 2003 x64, Windows XP, Windows XP x64, Windows 2000, Windows ME, Windows 98, Linux, Mac OS X, Mac OS 9, Mac OS 8, Windows CE.NET (Version 4.2 and greater) Commands: FIRST channel commands: OFF command : FF 01 00 (HEX) or 255 1 0 (DEC) ON command : FF 01 01 (HEX) or 255 1 1 (DEC) SECOND channel commands: OFF command : FF 02 00 (HEX) or 255 2 0 (DEC) ON command : FF 02 01 (HEX) or 255 2 1 (DEC) THIRD channel commands: OFF command : FF 03 00 (HEX) or 255 3 0 (DEC) ON command : FF 03 01 (HEX) or 255 3 1 (DEC) FOURTH channel commands: OFF command : FF 04 00 (HEX) or 255 4 0 (DEC) ON command : FF 04 01 (HEX) or 255 4 1 (DEC) Download: https://s3-ap-northeast-1.desertcartaws.com/sain-amzn/20/20-018-909/20-018-909.rar Review: Cheap. Works perfect for my purpose. - I have a virtual pinball cabinet, and I wanted to add a relay to control a fan for the "Whirlwind" game. I didn't want to spend a lot of money on this silly project. The reviews are so poor but I figured I'd risk it. There's a C# sample that Anthony Marshall provided, and it worked on this board out of the box. [...] I modified this to work in the pinball simulator's framework interface, and bam! My fan kicks on when the storm hits! I checked the other 3 relays and they work fine as well. The only negative is that the relays click a few times during boot up, apparently some issue with the FTDI chip. Sainsmart notes this in the product description on their site. Overall it's exactly what I was looking for. Review: Once this was done and I found an old 5 volt dc wallwart from a discarded switch this board works great. Pity the documentation - Step one download the VCP (Virtual Comm Port) driver from (xxx).ftdichip.com/Drivers/VCP.htm. After installing driver, plug in the usb cable and the board will be identified as a comm port. Use device manager to determine comm port #. Open comm port at 9600 baud, 8 bit, no parity, 1 stop bit no flow control. Mr. Merryman was correct in his command determination. The relays are selected by binary where: 0001 = relay 1 on = Dec 1 0010 = relay 2 on = Dec 2 0100 = relay 3 on = Dec 4 1000 = relay 4 on = Dec 8 Let relayvalue = decimal value of relay desired ie: relayvalue = 1 for relay one. Then send chr$(relayvalue) to the comm port. If you want multiple relays add their decimal values together, 1 & 4 would be relayvalue=9 To then turn relay 4 off, subtract 8 from relayvalue and send relayvalue=1, turning off relay 4 and leaving relay 1 on. Once this was done and I found an old 5 volt dc wallwart from a discarded switch this board works great. Pity the documentation is lacking. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B009A5246E | | Best Sellers Rank | #1,086 in Single Board Computers (Computers & Accessories) | | Brand | SainSmart | | Brand Name | SainSmart | | Coil Voltage | 12 Volts | | Connector Type | Usb | | Contact Material | Copper | | Contact Type | Normally Open | | Customer Reviews | 3.6 out of 5 stars 28 Reviews | | Manufacturer | SainSmart | | Maximum Switching Voltage | 12 Volts | | Minimum Switching Voltage | 12 Volts | | Model | 101-70-117-03 | | Mounting Type | Plug In Mount | | Operation Mode | Automatic | | Unit Count | 4.0 Count | ## Product Details - **Brand:** SainSmart - **Connector Type:** Usb - **Contact Material:** Copper - **Contact Type:** Normally Open - **Mounting Type:** Plug In Mount ## Images ![SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - Image 1](https://m.media-amazon.com/images/I/41aYDXWyvJL.jpg) ![SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - Image 2](https://m.media-amazon.com/images/I/41jZyEeyf7L.jpg) ![SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - Image 3](https://m.media-amazon.com/images/I/518fn+6phlL.jpg) ![SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - Image 4](https://m.media-amazon.com/images/I/41VsTGnVuPL.jpg) ![SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - Image 5](https://m.media-amazon.com/images/I/41-ALKbcy8L.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Cheap. Works perfect for my purpose. *by D***X on January 23, 2014* I have a virtual pinball cabinet, and I wanted to add a relay to control a fan for the "Whirlwind" game. I didn't want to spend a lot of money on this silly project. The reviews are so poor but I figured I'd risk it. There's a C# sample that Anthony Marshall provided, and it worked on this board out of the box. [...] I modified this to work in the pinball simulator's framework interface, and bam! My fan kicks on when the storm hits! I checked the other 3 relays and they work fine as well. The only negative is that the relays click a few times during boot up, apparently some issue with the FTDI chip. Sainsmart notes this in the product description on their site. Overall it's exactly what I was looking for. ### ⭐⭐⭐ Once this was done and I found an old 5 volt dc wallwart from a discarded switch this board works great. Pity the documentation *by D***B on March 31, 2015* Step one download the VCP (Virtual Comm Port) driver from (xxx).ftdichip.com/Drivers/VCP.htm. After installing driver, plug in the usb cable and the board will be identified as a comm port. Use device manager to determine comm port #. Open comm port at 9600 baud, 8 bit, no parity, 1 stop bit no flow control. Mr. Merryman was correct in his command determination. The relays are selected by binary where: 0001 = relay 1 on = Dec 1 0010 = relay 2 on = Dec 2 0100 = relay 3 on = Dec 4 1000 = relay 4 on = Dec 8 Let relayvalue = decimal value of relay desired ie: relayvalue = 1 for relay one. Then send chr$(relayvalue) to the comm port. If you want multiple relays add their decimal values together, 1 & 4 would be relayvalue=9 To then turn relay 4 off, subtract 8 from relayvalue and send relayvalue=1, turning off relay 4 and leaving relay 1 on. Once this was done and I found an old 5 volt dc wallwart from a discarded switch this board works great. Pity the documentation is lacking. ### ⭐⭐⭐⭐ How to use this on Android *by G***G on June 29, 2014* As others have said, the instructions and documentation really stink and the hardware has a few flaws. However, the comments on here really helped me to get this running reliably from an Android tablet. I'd like to add to the discussion to make this easier for the next person. Software: (1) You MUST set this to bitbang mode using the FTDI driver for your operating system. Specifically, for Android, I ended up passing FT_BITMODE_SYNC_BITBANG to the setBitMode method of ftDev. (See #3 below.) This cost me literally 4 hours of pulling my hair out. (2) The instruction set that Thomas Merryman posted is correct. You're writing a single byte with 0-F to the device to change the relay states. The product documentation is completely incorrect - ignore it completely. (3) To get going on android, I used a project called "Android Java D2XX". I'd put the URL, but Amazon would scrub it out. Google for the following and you should find it: "Android Java D2XX - Example projects to connect FTDI peripheral devices to an Android Host with the Java D2XX driver". For troubleshooting while getting up and running, the specific file that I modified to mess around with was DeviceUARTFragment.java, and specifically the SendMessage method. I modified that method to (1) set to bitbang mode (it is NOT in bitbang mode by default which tripped me up big time) and (2) convert the input from the app's UART screen (called writeText) to a byte (rather than a byte representation of a string of ascii chars). Then you can install the app on your Android device and use the UART GUI to write 0-15 and see the corresponding relay state changes. Hardware: (1) The circuit does not dissipate the voltage transient from opening a relay on a high inductance device (like a high power solenoid ... which I am using). You can overcome this by soldering on a freewheeling diode for each relay. Turn the board over - solder diodes from the "outer" pins surrounding the u-shaped holes. The diodes direction matters - it should point towards the USB port. (2) You can power the relays from the USB port by adding a jumper wire. Connect one end of the wire to the VCC terminal block then push the other end of the wire through the hole labeled 5V (just under R10), turn the board over and solder in place. ## Frequently Bought Together - SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM - SainSmart 16-Channel 9-36V USB Relay Module - SainSmart USB Eight Channel Relay Board for Automation - 12 V --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.za/products/4103638-sainsmart-usb-4-channel-dc-12v-relay-module-automation-arduino](https://www.desertcart.co.za/products/4103638-sainsmart-usb-4-channel-dc-12v-relay-module-automation-arduino) --- *Product available on Desertcart South Africa* *Store origin: ZA* *Last updated: 2026-04-23*