Using the Shelly i3 to automate in new ways!

The Shelly i3 has recently been certified for use in Australia and we are really excited to explore all of the use cases for this innovative device.  

Scene controllers are not new - battery powered Zigbee wall switches have been around for years and even Shelly have their WiFi Button to allow for wireless control of lights and other automations.  The Zigbee wireless wall switches are really convenient, but have some limitations:

  • The batteries used are often hard to come by and expensive to replace;
  • The style of the switch will almost certainly not match the style of the hardwired light switches in your home;
  • Zigbee switches require a Zigbee hub, and pairing is not always straightforward;
  • When it comes to using the switches to run automations (e.g. in Home Assistant), a bit of coding is sometimes required as the Zigbee events need to be parsed; and
  • Depending on the strength of your Zigbee network, commands may fail which can become frustrating.


The Shelly i3 attempts to solve many of these issues. It is a tiny mains powered device that sits behind your standard wall switches.  It has three smart inputs that can react to presses (or flicks) of your wall switch, which can in turn run automations either in the Shelly app, or your home automation platform of choice!  See below for some interesting use cases:

1. Smart RGBW bulbs

The great thing about smart bulbs is that they are really convenient, cheap and allow you to control colour and brightness through their apps.  Whether they are Philips Hue zigbee/bluetooth bulbs or Lifx WiFi bulbs, the ability to control the warmth of light and colour is a real plus over regular downlights.  The major problem though is when someone flicks the wall switch off and cuts power to the bulb, meaning it cannot be controlled via the app until the switch is turned back on!

The i3 solves this issue.  An electrician can wire such that the bulb always has power, and then wire the switch into a Shelly i3.  Scenes can then be created so that when the wall switch is turned off, a command is sent to the bulb to turn off and vice versa.  As the bulb still has power, you still have control via your app! 

The Shelly i3 means you can now choose between turning your smart bulb off at the wall, or via the app.

2. Two way switching


Two way switching can always be tricky with smart relays. Where your existing wiring does not allow for two way switching with a single relay, the Shelly i3 comes into its own.

On one switch, a Shelly 1 can be installed.  At your other switch (any switch of your choice, the switches do not need to be physically connected in any way) install a Shelly i3.  The Shelly i3 can be set to toggle the Shelly 1, meaning that you have achieved two way switching!

The ability to create two way switching across any pair of switches in your home is one of the real innovations that the Shelly i3 brings.

3. Garage door sensor


The Shelly i3 has three inputs that can be utilised to monitor the state of a reed switch.  If you have two or three garage doors, you can install reed switches at each of them, and the Shelly i3 will help to notify you when your garage doors are open or closed.  To be able to monitor three inputs with a single device costing $27 is unique given how little programming and flashing of software is required with the Shelly line of products.

These are just a few of the interesting uses for the Shelly i3.  We would love to hear how you are using the Shelly i3, or your interesting ideas on how the Shelly i3 might be used.  Email us with your ideas on info@smartguys.com.au - the best three ideas submitted in November 2021 will all receive a $10 voucher to spend anywhere at Smart Guys.