Xiaomi aqara sensor with Samsung home connect

[veeceeoh (Keith G)]

@wasim

my question is if it works 1 hour without any problem is doing on off is detect motion and does all functions properly exactly after 1 hour it just goes offline I’m pretty much newbie with these things but I was thinking it maybe there is a small change will help us

Only SmartThings would be able to make a change that would help, and I don’t think it’s likely that will happen because the issue with Xiaomi devices dropping their connection is because they don’t behave as Zigbee devices are supposed to.

Here’s the explanation from a SmartThings Software Engineer:

@tpmanley

As you probably know, the Xiaomi sensors are very sleepy. Most sleepy end devices that we support will wake up every 6 seconds to 2 minutes to check for messages and to make sure its parent knows it is still there. The Xiaomi sensors do this closer to once an hour. That is zigbee compliant behavior so everything is fine so far.

The zigbee specification includes a section called End Device Aging. It states that a parent must forget about a child that doesn’t check in for a certain amount of time. In other words if the parent (like the hub or another router on the network) hasn’t heard from a device within a certain amount of time it must tell the device to leave and rejoin the network. This isn’t an uncommon thing to happens on a zigbee network and most devices will handle this just fine. When the device does it right you’ll never even notice it was gone for a brief period.

By using a zigbee sniffer I can see all the communication between the sensor and the hub. The sensor is quiet for about an hour and then sends a checkin message to the hub. The timeout for end devices has elapsed so the hub’s zigbee radio doesn’t recognize the sensor anymore. Therefore per the specification it sends the sensor a leave and rejoin request. The sensor replies with a message saying it is going to leave and rejoin. Then it does leave but it does not attempt to rejoin. Instead it appears to factory reset itself. This is why it drops offline and I believe is non-compliant behavior.

(a partial quote from this forum post)

So as you can hopefully see from the above explanation, even though the Xiaomi devices seem to work fine for the first hour, the hub is looking for a different kind of check-in message from the device, which Xiaomi devices send either every 50 or 60 minutes. Then, because the Xiaomi device doesn’t re-join as requested, the connection is dropped.

In the current firmware of the SmartThings v2 hub, it appears that Xiaomi devices are allowed to keep their connection when they check-in with the hub, while on other SmartThings hub products, such as the Home Connect or SmartThings Link for NVIDIA Shield, probably send the leave and rejoin request which results in the lost connection.