16-Channel I2C Relay Board Driver



The I2C-RELAY16 is designed to piggyback on commonly available, Chinese-made, boards with 16 SPDT relays.   (We don't sell the relay boards directly, but they're available from multiple sources - various vendors on Amazon (#1, #2), SainSmart, or even direct from China on eBay.)

Included are two 6P6C I2C connectors, a female 20-pin dual row connector to attach to the relay board's header, a PCA9671 16 channel I2C I/O expander, and three address jumpers to select 1 of 8 possible addresses.  The I2C connector makes it easy to add the I2C-RELAY16 to our various I2C products and adapters.  For Arduino users, be sure to check out the I2C-RELAY16 Library Reference for details on the Relay16 library and example sketch.

For a Qwiic compatible version (good for use with a Raspberry Pi), please check out the I2C-RELAY16-QWIIC.


2.22"(L) x 1.04"(W)


The complete gEDA design files are available on GitHub.


6P6C I2C Connector Standard

Arduino Library Reference

  • $20.00

  • 10 or more $15.00

Related Products

5V I2C Adapter for Raspberry Pi

5V I2C Adapter for Raspberry Pi

This I2C adapter allows you to connect 5V I2C peripherals to the Raspberry Pi.  It performs the..


DCC Decoder Shield for Arduino

DCC Decoder Shield for Arduino

The ARD-DCCSHIELD is an optoisolated interface shield for connecting an Arduino (as a decoder) to a ..


Qwiic-Compatible 16-Channel I2C Relay Board Driver

Qwiic-Compatible 16-Channel I2C Relay Board Driver

The I2C-RELAY16-QWIIC is a Qwiic-compatible relay driver board designed to piggyback on commonly ava..


News & Application Notes

A Qwiic Update

This week I’d like to introduce you to two new Qwiic-compatible I2C products in our lineup:  a new Qwiic-compatible, 2 channel analog to digital converter, and a re-spin of our popular I2C-RELAY16 into a Qwiic-compatible 3.3V version. 

To explore how each of these can be used through a simple example, I’ll walk through an example connecting the ADC to a liquid level sensor, using Python on a Raspberry Pi to read the data, and then act on that liquid level by triggering a relay. 


High Current DCC Accessory Decoder

One of our customers was trying to build an accessory decoder using our I2C-RELAY16 to drive a bank of relays for high current loads, and they were having a bit of trouble.  So, I thought I’d sit down and work through the issues tonight, as I’ve always thought having an accessory decoder with isolated, high current relay outputs might be nice. 

[See image gallery at www.iascaled.com]

Controlling Relays with a Raspberry Pi

Ever wanted to control some real world hardware with your Raspberry Pi?  Every now and then, we get questions about using either our I2C-RELAY16 or I2C-XIO boards from the Pi, and it’s been on my eternal backlog list of “I should do a quick article on that…”   So let’s break this logjam and get down to controlling a cheap Chinese 16 channel relay board with a Pi (available from SainSmart and others).  Because this provides 16 relatively high current, isolated output channels, this seems a great place to start, and it’s an easy hour project.

A Raspberry Pi 3 controlling a 16-channel relay module on my bench


Solar Car Teams

As alumni of the Iowa State University Solar Car Team, Team PrISUm, we recognized that many of Iowa Scaled Engineering’s products could be used by teams competing in solar racing competitions.  In fact, MRBus had its origins in the Sunrayce ’99 car, PrISUm Phoenix.



Write a review

Note: HTML is not translated!
    Bad           Good