Help placing zigbee repeater in ideal location


(Ron) #1

I purchased a SmartThings Outlet to act as a repeater. I have mostly zwave devices in my system so this Outlet was purchased to improve connection between STv2 Hub and ZigBee Presence Sensors kept in my car.

Currently the connection works but I want to make it a little more solid. I do get occasional leaving/arriving events that are false.

So I have two options and wonder which would be best. One location would be at very close to the midpoint between my hub and my sensors. The other idea would be to place the outlet in the Garage since I am assuming the battery based presence sensors put out a weaker signal. This would allow a very solid connection between the sensors and the outlet. Then I assume the outlet being powered would have a stronger signal to reach the hub.

I think both locations will improve my zigbee mesh. But thought I would ask here to see what others in the community have experienced.

Does the system have any means of determining how strong a signal the hub is receiving ?
I see these values on the sensors but not sure what they mean. (This is without the outlet)
Sensor 1
lqi: 100 %
rssi: -72 dBm

Sensor 2
lqi: 100 %
rssi: -71 dBm


#2

rssi is the received signal strength. -40 is stronger (often presumed closer) than -50.

https://docs.digi.com/plugins/servlet/mobile#content/view/3407998

LQI is the link quality, usually calculated from the rssi and the error rate. So 100% is very good. (Some systems calculate lqi only from rssi without taking errors into account. That can be bad if there is interference as you might just be getting the strength of the interferer. I’m assuming ST includes error rate, but I don’t know for sure.)

.
http://atmel.force.com/support/articles/en_US/FAQ/RSSI-vs-LQI-What-is-the-difference

Looks like the two locations are about the same. So personally, I would probably put the repeater inside the garage as that tends to be the area where there’s the most trouble. Usually you want the repeater as close to the shared interior wall as possible so it get the signal through that wall. But you may just have to experiment.

Remember that every time you move the repeater to a new physical location you have to do a Zigbee heal so that the neighbor tables get updated. And ideally you want the presence sensors at the position where you want them to be detected.

To do the heal, just take the hub off power (including off battery) for at least 15 minutes. Then put the hub back on power and all the devices should update their neighbor tables. This can take a while, even a few hours, before you see improvement. .


(Ron) #3

Thanks for the info. IF -40 is better then -50 the -70 seems bad but 100% seems good so maybe I don’t even need the repeater.

I’ll try to two locations and see how the numbers change.

My two numbers provided are both without the outlet installed. I have to sensors hence the two sets of readings.


(Ron) #4

I started by placing the outlet inside my home at the midpoint and get really good numbers now so think I might just leave it there.

Sensor#1
lqi: 100 %
rssi: -34 dBm

Sensor #2
lqi: 100 %
rssi: -33 dBm


(Teo Tod) #5

Hi,
Where do you see the lqi and rssi?
I cannot find this info neither in app, neither in dev web app?
Best,
Teodor


(Ron) #6

ide.smartthings.com => My Devices => Select your presence sensor

So far Presence Sensor is the only device I have found has these values.


(Teo Tod) #7

Oh, that was fastest response I ever so - thx so much, Ron! :slight_smile:
Now I see why I cannot find those values, as well as why the Presence sensor battery depletion is so high (rssi & lqi are very very very power consuming :slight_smile: )

Still interested why the capability “Power Strength” it is not in outlets too as they do not rely on battery. Any Samsung SmartThng support folk able to give an answers to that?