• USB-I2C-SPI-4VI4SRMx-2H-12V

4 signal relay board, 4 wide voltage input, Multi-protocol card with 2 part horizontal connectors.

General purpose relay card with 4 opto-isolated, 12V operating, 120V, 3A signal relays and 4, 3V to 60V, AC/DC, opto-isolated voltage sensing inputs.

This card has 3 communication options:

  • USB
  • I2C
  • SPI

This card also has 2 powering options:

  • USB power
  • External 5V DC with reverse polarity protection

Two LEDs indicate data transfers between your control hardware and the relay card for help with debugging and testing.

Each relay channel or voltage sensing input has its own LED to indicate status.

The card has been designed with future expansion in mind including access up to 6, 5V DIO channels connected to the main controller. The programming pins for the control processor are also available to enable re-purposing of the card by loading application specific software.

Nylon feet are fitted in each corner which will take self tapping screws.  They can easily be removed to allow the cards to be mounted on pillars or stacked.  

(Perspex cover under redesign - currently unavailable for this model)

These are industry standard relay boards and products.  High quality equipment, for professional electronic automation, connectivity, and control.

EasyDAQ products are used in research and education, security, industrial applications, power and energy management, motor and device control. There are uses across various industries, including maritime, rail, automotive, automation, measuring and calibration, agriculture, medical, sanitation, light and power solutions, fire protection, security, and many more.

You can order any of our boards with customisations or without connectors fitted - contact us for prices

RoHS compliant and CE marked.

'Pre-Order' simply means that we will build to order. Delays are minimised - with most orders dispatched within 48 hours. More time is needed if we have limited PCB stock. If you require clarification of timings, please phone or email us. 

Download datasheet

Quickstart Guide

EasyDAQ is primarily a business-to business seller, supplying products around the world, therefore advertised prices exclude VAT. Customers in the UK and Northern Ireland will be charged VAT  at checkout.


Operational Parameters
Manufacturer EASYDAQ
Control Interface USB I2C SPI
Relay coil voltage 12V
Relay Channels 4
Relay contact current 3A
Digital input channels 4
Relay Type SIGNAL
Digital output channels 4
Opto-isolated YES
Connector TWO-PART CONNECTORS HORIZONTAL
Wide Input Voltage YES

USB-I2C-SPI-4VI4SRMx-2H-12V

  • Brand: Easydaq
  • Product Code: USB-I2C-SPI-4VI4SRMx-2H-12V
  • Availability: In Stock
  • £108.51


  • 10 or more £86.81
  • 25 or more £77.04
  • 50 or more £72.27
  • 100 or more £67.93
  • 250 or more £63.48
  • 500 or more £58.81

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Tags: SIGNAL, USB, SPI, I2C, wide input, 12V, wide input voltage, vertical connectors, USB 4 relay, relay board, USB-I2C-SPI-4VI4SRMx-2H-12V, Free shipping, EasyDAQ, UK