I finally received the SNZB-02 sensor I ordered weeks ago to evaluate, pairing it to my ZHA flashed bridge and getting the data showing up in HA was without issues and so far it seems to be doing what I expected it to do and sending the data to HA. Before I order a bunch more of these I thought I’d see if anyone has any longer term experience? Are they reasonably reliable? Does the accuracy generally hold up from one unit to the next? How’s the battery life? Mine was showing 73% out of the box so I’m guessing the battery that came with it is not going to be a good measure, despite arriving with an insulating strip in place.
Also are there better sensors I should be considering instead? At under 10 bucks these are inexpensive and they’re a nice form factor but they’re also the only sensor of this type that I’ve tried so far.
Good to hear. I’m interested in experiences with the sensor itself, I would expect that if it works well with one bridge it would work well with another. I’m not married to ZHA, I could switch to something different easily enough if there was a compelling reason but I don’t want to spend money on a dozen sensors and then find out a few months later that they’re junk. At any rate I ordered a handful of them and will see how it goes, the one I have so far is still working great.
I have four or five of these scattered in the house. Currently I’ve had two stop working after a couple of months, changed the batteries, needed to delete from Zigbee2MQTT and reconfigure for them to show up again. Actually they show up again but don’t actually work. A bit of a pain. I don’t entirely understand why this is happening.
I’ve been experimenting with one of the Sonoff SNZB-02 and the Aqara Lumi zigbee climate sensors a little. Just a short term with the Sonoff so far. It sends temperature updates by default about 2 to 4 times per hour. I understand that folks have found ways to change this reporting interval, but I have not yet tried. As shown in the chart below, the Aqara checks in at about the same interval.
I have the Sonoff connected VIA a Centralight wall plug router to a Tasmota’ed Sonoff zigbee bridge managed by ZHA, and that experience has been in a word ‘strange’. The Sonoff SNZB-02, has delivered readings at the rated described above for 7 days I have had it operating, however as far as ZHA is concerned it has NO routes back to the coordinator. In the ZHA visualization, it is a floating circle with no links. To make it even more strange, 2 or 3 times I have detected, for period of a couple hours, the Sonoff SNZB-02 did show a route connecting it to the network, however it was VIA a different CentraLight wall plug router.
I am not sure if this routing issue is caused by the CentraLight or by the Sonoff, I suspect a combo of both. I am exploring these strange routing behaviors with several combos of routers and end devices. What makes the Sonoff SNZB-02 unique, is that it rarely shows a connection to the network as far as ZHA detects, however it delivers its data consistently…
Zigbee is interesting, but so far with my experiences with the low cost zigbee weather sensors, Sonoff and Aqara, I would recommend going instead with a Bluetooth Low Energy setup. Both the Govee (several models) and Xiaomi LYWSD03MMC (with the hacked firmware) offer much more frequent data updates, good range, low price and solid battery life.
Good to know, and thanks for sharing.
I have seen other post reporting around +10% compared to other devices.
I have another devices, cheap one not so trustable, that differs 8-10% with SNZB-02…so i was little bit unsure what to believe.
The discrepance seems to be just humidity, temperature is quite similar to other devices.
temperatures are accurate BUT look at the humidity!
It currently shows 80% to 95% humidity, but I tested with 3 other hygrometers and the real humidity is 63% in grow tent 1 and 72% in grow tent 2
Hi guys, I am a bit confused. I read conflicting comments concerning the accuracy of the humidity sensor. Can someone share their experience.
Any alternative is also welkom. Accuracy (and size) is very important in my case, I will be using it for my (cigar)humidor.
I have 3 of them, no others and my first/only experience with these kind of devices (had lights and switches)
Compared the temp with a thermometer and had to adjust all 3 of them with the same value (-1,3°C).
I have no other means to compare the humidity values but they seem to be correct.
Fluctuation : It seems the sensor is fluctuating a bit. In a steady environment (cigar humidor and ziplock bag) the fluctuations were within a range of 2% which seems reasonable to me.
Offset: I read comments about testing the accuracy by comparing it to another sensor. In my opinion, this is very strange (how would you know the other sensor is accurate?).
What you should do instead is the “salt test”. Create a conditioned environment where you know (thanks to physics) that the humidity will be a certain value. (75% in this case). You do the test and there you have it: the offset. About 4% in my case.
Note that the other sensor is off by 2% in the other direction.
Because I could not find if the offset is to be adjusted in the Sonoff SNZB-02 sensor, I did it within HA by adding the following code to the configuration.yaml:
Just wanted to share my personal experience with the Sonoff SNZB-02. I purchased two of them. On one of the two devices, the setup button was depressed into the case. I popped the case open (there are no screws) to discover that the tiny microswitch was poorly soldered to the board. It actually fell off into my hand when I tried to press the button with my finger.
I was able to configure both devices. For the one without a setup switch, I used a flat blade screwdriver to bridge the contacts for five seconds. Both devices reported temperature, humidity and 100% battery levels. I walked away thinking that I was done.
A few days later I logged in hoping to see a graph of temperatures and humidity. I was disappointed to find that the devices (both) stopped reporting and were now “unavailable”.
For the one device that had a setup button, I did a reconfigure to get it up and running again. It was reporting data one again. In my logbook I have a “Identifybutton” event, but no further logs from the device. It reported the temperature and humidity once.
The next morning I expected to see a graph of temperatures and humidities. Once again, nothing. Only the one reading when I reconfigured the device. Perhaps I’m missing something, but my experience so far can only be summed up as disappointing.
I bought 4 of them, mostly because I like the bigger battery.
One had the same problem as @paulcarlin is reporting - the setup button was depressed into the case :-/ , very poor quality and not something I would expect for a button (that gets broken when you press it omg)…
And the other 3? Over the course of 3 days, only two are somewhat reliably report the temperature. One of them just drops off, when I “repair” it by holding the pairing button, it reports the temperature like once and then drops off. This is next to 3 additional routers (extending the signal) that are connected just fine, so it’s not out of range or something. Changed the battery, same behavior… The sensor, however, reports more often than just once in an hour.
50% survival rate is not great , seems like a hit and miss.
I bought two SNZB-02 and added them to my Home Assistant on the RPi 4.
Pairing was easy to ZHA.
One did not really want to update the Humidity, temperature was OK.
Cured with doing a Reconfigure of the device.
Since then the temperature and humidity are reported. Not often, e.g. it needs 0.2 change for the temperature to report. So it saves battery that way I think. After two days the batteries are still at 100%.
So far so good. Accuracy is 0.2 degrees, humidity is 2%.
I have also two Aqara Temperature and Humidity Sensors. One is just as good/bad as the Sonoff devices, the other is eating batteries in a day, so garbage now.
The spikes were created by breathing on the sensors, to force a report.
Home Assistant 2023.5.2
Supervisor 2023.04.1
Operating System 10.1
Frontend 20230503.3 - latest
Zigbee Home Automation
Been running three SNZB-02 for over a year on MQTT. Did salt test and compared temperature with other thermometers - I my case it is all in spec. Battery fluctuates after re-pair, but other than that these are still close to 100%. One out of three sometimes disappear from network, but it’s only happened few times in a year.
People experiencing connection issues - ZigBee is very weak especially for battery powered devices. Something like moving sensor 5cm in other direction might cause massive drop in link quality. Things like using electrical devices can also cause network degradation. I just keep an eye on situation using chart
I also have negative experience with Sonoff SNZB-02. Bought 2 of them, to work together with SONOFF Zigbee 3.0 USB Dongle Plus + ZHA. Both were paired without any issues, humidity is updated every ~30s (or every minute, not sure here) reliably, but temperature was updated once right after pairing, and then not updated at all. I tried multiple times to remove battery and re-pair, but the behavior is still the same
I can’t blame the setup, because Aqara sensors works perfectly in the same time.
, seems like a hit and miss.
