There is a lot of information available about this generally, but the field is moving quickly and it's difficult to judge what information is dated.
I have 3 harmony hubs: one for my theater room, one for my living room, and one for my exercise room. A 4th is likely in my near future for the bedroom. I have multiple Alexa devices as well, one in each of the aforementioned rooms.
Alexa, through the Harmony skill, supports only one Harmony hub at a time. There is a skill to add a second hub, but I'm already past that and still adding hubs. So, instead of using the Harmony skill I have a Samsung SmartThings hub (v2) where I've added all of my Harmony hubs and activities. Through the SmartThings skill then, Alexa has basic on/off control of my Harmony activities as "scenes".
This is where things start to fall down for me though. At first when I asked "Alexa, turn on the TV" she'd tell me that she found multiple matches and couldn't do anything. Then I found Groups, where I added the Alexa device for a given room along with whatever lights and other things are in that room, plus the Harmony activities for the hub in that room. I expected that to tie that Alexa device to the other things in that group, so when I say "Alexa, turn on the TV" there'd now be only the one matching because it's in a Group with the Alexa device. That didn't seem to change the behavior at all though, have I misunderstood how the groups are used? Do they guarantee fall down if you have multiple things named the same?
I've also tried renaming all of the activities from "Watch TV" to "Theater TV", "Living Room TV", and "Exercise TV". I can't quite tell if those changes correctly propagated through Harmony to SmartThings and then to Alexa, but presumably not because she tells me there is no matching device when I try to use those phrases.
Finally, assuming I could work out Alexa controlling my various activities correctly, it seems that going through SmartThings to control them limits me to basic on/off capability, no volume or channel control, etc. Is there just no way to get comprehensive voice control of a Harmony hub once you have 3 or more?
- Is SmartThings the best way to get Alexa to control multiple Harmony hubs?
- Can you get full Harmony control through Alexa with SmartThings as a middle man? Or are you definitely limited to just on/off?
- Should Alexa's Groups allow me to have multiple devices with the same names and still have Alexa control the right ones based on which Alexa device hears the command?