Posted on by Doug Roberson

How can you turn on multiple lights with one smart switch?

Using a Shelly module and DDD (Direct Device to Device communication), you can use one device to turn on another or a whole chain of others.

I started a project today, where I’m installing a Shelly 1 inside a floodlight, so that if a motion sensor is tripped on one side of my house, I can turn on multiple lights, including indoor lights.

Installing the Shelly 1 gives me lots of options – I can add the lights in question to a group (multiple devices of the same type, in the same room or different rooms) or to a scene.

One of the simplest but most powerful options, though is DDD (Direct Device to Device communication). With the Shelly 1, there are six actions where you can execute DDD:

Button Switched On
Button Switched Off
Button Long Pressed
Button Short Pressed
Output Switched On
Output Switched Off

The way that it works is that you enable one or more of the above actions and enter the URL you wish executed. Obviously, any Shelly API command will work here, allowing you to perform a number of functions, but the feature is actually agnostic. You can execute any URL command.

For example, you could send a custom value to a listener on a webserver and perform whatever action is programmed there. If you have another device that allows you to send commands via URL, like a Wi-Fi plug flashed with Tasmota, then you can send that command from your Shelly. Please note – DDD is not currently available on RGBW2 or 4Pro modules, though these devices can be the target.

Here’s how to use DDD with a Shelly relay:

  1. Open the Shell app and tap the relay you want to trigger DDD
  2. Tap the Actions menu
  3. Select the URL option you want to use (I use Button Switched On in my example)
  4. Tap Enable
  5. Enter the URL (example – http://192.168.1.30/relay/0?turn=on)
  6. Tap Save

The URL (http://192.168.1.30/relay/0?turn=on) triggers the relay on a Shelly 1/1PM relay at 192.168.1.30 or the first relay on a Shelly 2.5 or 4Pro.

It’s THAT easy. It’s no problem to chain together an entire series of devices this way. The best part is that it works 100% local, no cloud component is needed, no hub is needed.

Time to set up? 21 seconds, including app load time.

For more details on DDD, read HERE

Shelly offers an ever expanding catalog of products that allow you to customize your solution for your automation needs.

You can order whatever you need by visiting the US or Europe Shelly online stores!