2 Motion Sensors on 1 SmartThings Hub Controlled by 2 Amazon Alexa Accounts

I recently purchased two Dome Motion Sensors for automating my bedroom lights. I’m using one motion sensor (Motion_Sensor_1), in my room with my Alexa account (Alexa_1). My brother is using the other motion sensor (Motion_Sensor_2) in his room with his Alexa account (Alexa_2). Both motion sensors are connected to the same SmartThings Hub and each of us have our own Samsung account that are members of the Locaiton.

Desired Functionality:
The ability for both of us to enable create routines via Alexa to turn on lights when motion is detected.

When I initially connect the Motion_Sensor_1 to Alexa_1, the routine works as expected and turns on lights when motion is detected. However after connecting Motion_Sensor_2 to Alexa_2, the routine within Alexa_1 no longer works and only the routine in Alexa_2 works.

To trouble shoot, I removed the SmartThings Skill from Alexa_1 and proceeded to reinstall, discover the devices and set up the routine. After doing this the routine worked for Alexa_1 and Motion_Sensor_1 but the routine stopped working for Alexa_2.

The confusing part is that when the routine stops working in either Alexa after installed in the other. You can still seeing motion detected in the Alexa where the routine is no longer working (ie If i go to devices and click on the motion sensor it shows motion detected even thought the routine isn’t triggering).

Has anyone experienced this or know of a workaround?

This is a known issue. :disappointed_relieved: Basically you cannot connect a single smartthings account to two different Amazon accounts. As you noted, it will keep swapping which devices get controlled.

There’s been a note up in the official support base FAQ for about two years that says they are hoping to be able to increase the number of accounts that can work, but again, it’s been up for two years.

I understand the situation you run into because we had a similar thing at my house (three housemates), but people more often run into it when they have two separate buildings with two smartthings locations on one SmartThings account. But it’s the same issue.

There are a couple of possible workarounds although they can add lag and they get a little kludgy. You can try using IFTTT as a “man in the middle”, but then you have to use the “trigger” construction which a lot of people don’t like.

What we did at our house was just to get a Google mini for the housemate who wanted to keep everything separate and he uses that for the home automation commands. He still has his own echo with his own Amazon account but he doesn’t try to control smartthings through that. It solved the problem in our house, but it does mean you have to remember in his room that it’s google controlled not echo controlled. However, that doesn’t get you to the echo routines, so it may not work for you.



Thank you for the detailed explanation! I was concerned there might not be a solution.

I thought maybe having two distinct Samsung Accounts (Account_1 (Mine) and Account_2(My brother’s) tied to the one Location (My_House) with myself as the owner and my brothers account (Account_2) as a member of the home.

So when enabling the skill we both sign into SmartThings w/ our respective accounts (Account_1 and Account_2).

And the google option may work, I would soley use it for lighitng automation via SmartThings and let all other routines reside in my Alexa.


Why do you need Alexa to turn on the lights when motion is detected? Just use a Smartthings automation to do it.


I’m with @Paul_DeFeo on this one. SmartThings capabilites far outshines Alexa Routines. Is the device you are trying to turn on via motion not connected to SmartThings? If not, then can it? This will solve your issues.

@Paul_DeFeo, I wanted to incorporate Alex voice commands and trigger music to play from Spotify in addition but that’s really just a nice to have. The approach through the SmartThings hub may work well, I’ll give it a shot!