WARNING - WARNING - WARNING
In late April 2020, Samsung released a new smartthings skill for Alexa. If you are using the previous skill and you disable it, you will not be able to go back to it. Instead, when you re-enable the skill, you will get the new one. And a new one has some bugs.
As of July 2020, the big bug remaining for Alexa routines is that the new skill cannot see all of the child devices in smartthings. So some people have lost control of things like a Fibaro two dimmer and some fan controls.
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. So you can set up the logic on the SmartThings side however you want, then use webcore to set the virtual contact sensor open or closed as you need it, and that will trigger the echo routine. Or you can use a custom DTH which is both a virtual contact sensor and a virtual switch, and then turning the switch on will mark the sensor as “opened.“ So then you don’t need webcore, you can just turn the switch on and off with the official smartlights feature.
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.
See the following How To article in the community-created wiki for details, including a DTH if you want to use the combined sensor/switch method.
(and in particular, if echo 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!
Old Information from prior to August 2018*
If this were a wiki entry, I would delete everything in this post from this point on. But because it’s part of a discussion thread, I’m going to leave the old information so that the comments in the remaining posts still make sense. But remember that as of August 28, the answer to this question is now yes, you can, using the Contact sensor method, as long as you are in the US or the UK.
If you are outside the regions where Amazon support this, then you would have to use the older method detailed below.
This question gets asked a lot, mostly because the echo can work with so many different devices, including many that don’t integrate directly with SmartThings. So many people would like to be able to turn on a virtual switch in SmartThings and have that cause echo to activate one of its own echo groups or echo routines.
Prior to August 2018, the only thing that you could do was pretty weird, but it does work, and some community members are using it.
What they did was set up an inexpensive android device right next to an echo device, and then automate that android device speaking a command that the echo will understand.
This will work fine. It’s just a little strange to set up an automated speaker so you can avoid personally speaking to the echo. And of course it doesn’t solve those use cases were the reason you didn’t want to speak to the echo was because you wanted quiet.
If you have a device that can do text to speech (TTS) like a Sonos or some of the other DNLA speakers, you could also use that in the same way, and then the implementation is really simple, because there are already official features in SmartThings to cause a Sonos or similar device to speak a notification. Or use the community-created smartapp Big Talker.
If you don’t already have this kind of speaker, again, you can just get an android device and use LANnouncer, although the technical set up for that one is much more complex. (LANnouncer can even be triggered by IFTTT recipes without having smartthings in the middle.)
Both of these are based on the same idea: you are going to automate when the second device speaks a specific phrase, and then echo will react to that phrase being spoken just as it would to a person saying it.
So there you have it. You set up automation to tell your second speaker device to say a specific phrase when a specific event happened, and then your echo responds to that just as it would to person saying the same phrase.
that’s the only method that was available until August 2018. But now you can use to contact sensor method instead.