Breaking News!!! As of August 2018, a SmartThings-connected Contact or Motion Sensor can now trigger an Amazon echo routine if you live in the US, Canada, or the UK !!!
Amazon has now added the ability for some sensors to trigger an Amazon echo routine (not a smartthings routine), which does let you trigger other smart home devices which are not connected to SmartThings without having to speak an echo command! Or you can set it up so that your echo devices will speak a customized phrase, play a doorbell chime, or various other sound effects.
And even better, that contact sensor can be a virtual contact sensor. And SmartThings let’s you create a virtual device which is BOTH a switch and a sensor. So you can set up the logic on the SmartThings side however you want, then turning the switch on will mark the sensor as “opened.“ So you can just turn the switch on and off with a SmartThings routine or other automation.
The setup using a physical contact sensor is very easy. The set up using a virtual contact sensor is more work, but may well be worth it.
This now works for US, Canada, and UK accounts. It is likely that more countries will be added in the future, just check your Alexa app to see what’s possible.
Here’s the Alexa article on creating a routine.
Routines are in an if/then format, only Amazon calls it
When this happens/action
For “When this happens,” choose “Smart Home” and then pick the sensor (physical or virtual) you want to trigger the routine.
For “Add action,” choose “Smart Home” if you want to have Alexa control a device.
Choose “Sounds” if you want to have Alexa Play a sound effect like a doorbell chime or dogs barking.
Choose “Send announcement” if you want to have any or all of your echo devices speak a custom announcement.
Choose “Skills” if you want to have Alexa activate one of your skills without having to speak to it.
December 2020 Update
If you live in the United States, Amazon has now added the ability for a “custom action” as the last step in a routine. This allows you to have a routine do anything that you can speak to Alexa. This is a great way to add partial Integration with devices/skills that work with Alexa but not with smartthings. However, it is still only one way: you can have smartthings as the “if“ using the virtual Sensor method and the other device/skill as the “that“, but not the other way around for most items.
See the following How To article in the community-created wiki for details, including an Edge Driver if you want to use the combined sensor/switch method.
(if Alexa can see your sensor but the sensor will not trigger an echo routine, follow the steps in the how to article exactly and that will fix that problem. )
We should also mention that as of November 10, 2018, Amazon echo buttons (two for $20, about the size of a deck of cards) can also trigger an echo routine. So you can press the button and have the echo routine turn on a virtual switch which then triggers pretty much anything you want in SmartThings. The button won’t be visible to smartthings, but it’s a nice alternative means of control if you already have an echo in that room.
Also, as of November 2019, they have also added some sound effects options, including doorbell chimes, a dog barking, and sirens. Thanks to @fido for pointing that out in another thread!
And as of March 2021, Flic buttons are another physical button that can be used to trigger an Amazon routine.