shelly uni Problem with Shelly Uni + 3x DS18B20 temperature sensors

[Luke.Starkiller]

Hi
Just bought and set up a Shelly Uni with 3 DS18B20 temperature sensors. Had no problem adopting it, and when adding the 3 addon sensors I could see them all and add them. The problem is that they each lose connection on and off. I can see that they show up as N/A in Shelly Cloud for a couple of seconds and then the value comes back. They don't do it at the same time, often just one of them. But all 3 are affected. I use Home Assistant and I can see the gap in the history chart.

The other problem is that they out of nowhere report about half the correct temp for a couple of seconds then jump back to the right temp. All 3 of the sensors have been lying on my desk for 48h and it's about 20-22c in my office, but they all have some reports of 5-10c over the past 24h.
The higher value 25c+ is when I'm holding them in my hand.

Does anyone have a clue what's going on?



 In shelly cloud shows that temp sensor 1 and 2 reports lower temps than it should from time to time. And the 3rd picture shows whats shelly cloud shows when a sensor loses connection for a couple of seconds before coming back.

Home assistant 15min graph showing the gaps that are reported by all 3 sensors.

In Home assistant 24h graph showing the frequency of the 10c measurements wrongly reported.

[terae]

Some of my clients and -teme- from this forum (when testing) have had also some similiar things happening... It's possibly reason of lack of some filtering of data, when there's some times peak values as kind of status code from recently restarted 1-wire DS18B20 or so... another possibility is some issues with most new batches of DS18B20. How ever error values should be allowed to be filtered out if not automatically done.

Edit: Forgot to tell, that if I haven't got it wrong, it's under inspection to do fix at Shelly (?)

[mschaeffler]

@Luke.Starkiller Do you have an Uni or a PlusUni?

I have seen similar things with PlusUni.

[Luke.Starkiller]

On 4/6/2024 at 3:36 PM, terae said:

Some of my clients and -teme- from this forum (when testing) have had also some similiar things happening... It's possibly reason of lack of some filtering of data, when there's some times peak values as kind of status code from recently restarted 1-wire DS18B20 or so... another possibility is some issues with most new batches of DS18B20. How ever error values should be allowed to be filtered out if not automatically done.

Edit: Forgot to tell, that if I haven't got it wrong, it's under inspection to do fix at Shelly (?)

@terae These are the 3 wire DS18B20.

 

On 4/6/2024 at 3:46 PM, mschaeffler said:

@Luke.Starkiller Do you have an Uni or a PlusUni?

I have seen similar things with PlusUni.

@mschaeffler It's the PulsUni.

Edited April 8 by Luke.Starkiller

[Dimitar]

In next firmware release we implement a filtering which solve such a problems. You will have it in 2 weeks. 

[terae]

11 hours ago, Luke.Starkiller said:

@terae These are the 3 wire DS18B20.

 

@mschaeffler It's the PulsUni.

The technology is called 1-wire. You can feed these from any DC source locally and just transfer data by one wire, another one has to be same ground but not exactly in same cable.

[terae]

10 hours ago, Dimitar said:

In next firmware release we implement a filtering which solve such a problems. You will have it in 2 weeks. 

Great! Thank you for info. Many are waiting to have that solved.

[Luke.Starkiller]

17 hours ago, Dimitar said:

In next firmware release we implement a filtering which solve such a problems. You will have it in 2 weeks. 

Hi Awesome! will it fix the gaps in the measurement or when it sometimes report 10c lower temp and then jumped back?

[janro]

Was there a fw fix?

Still having this issue with UniPlus and the mentioned temp probes. N/A showing every 2nd second, alternates with proper values

[Luke.Starkiller]

I just updated my Shelly UniPlus and I still have the same problem, just as @janro. About once every 10 seconds one of the values shows NaN / Null, and then after the next poll, it shows normal values again. Is this really the intended behavior? I bought the UniPlus and 3x DS18B20 instead of 3x  H/T because I thought it would be a better solution for getting the temperature in 3 different places, but it has only given me a headache so far. 

Do you have any suggestions @Dimitar?

EDIT: This is also a gen2 device so maybe it should be moved to the right forum.

Edited June 22 by Luke.Starkiller

[RickB3n]

My shelly uni had been working fine for months, but today the three ds18b20 temperature probes mysteriously disappeared.

I tried to restart but they no longer appear on the cloud, what could it depend on?

The shelly power supply is correct, I can see it with the ADC.

Unfortunately I don't have physical access, but the hardware should be ok.

[loukote]

Hi, i also have the N/A problem, with two Uni Plus devices and one DHT22 sensor on each. The devices are up and running, just not showing the data. It happens independently or both at the same time. Reboot does not help. What helps is to switch power off and back on. But then it come back, sooner or later.

Both Uni Plus are on the same 12V DC source. The spec of the source seems to be enough for both. Could the consumption be somehow higher in a different place for a reason?

But i was writing a script and testing for a month in a room and it happened only once or twice. What changed is that now they are placed in a cellar. I was wondering if the issue could be due to humidity (~80%)?

[Dreckfresse]

Ich habe ein ähnliches Problem an 2 Plus UNI mit DHT21 (AM2301) mit schwankenden Temperaturen (nicht bei der Luftfeuchtigkeit)

beide DHT21 waren vorher an Gen1 UNI montiert und hatten jahrelang keinerlei Probleme!
 

installiert war bis heute Morgen die Stable 1.4.0 und jetzt die 1.4.2 beta 1

dieser Fehler ist immer noch vorhanden 

 

[Alex8974]

I have the same problem with 3 Ds18b20 and shelly 1 plus with add on, The devices are up and running, just not showing the data. It happens independently or both at the same time, I have always one Ds18b20 which stay running, but it's never the same. Reboot does not help. What helps is to switch power off and back on. But then it come back, sooner or later. 

[Bajen2001]

I have the same problem as @Alex8974.  Must do a power off and power on and then the Shelly Uni with 3 Ds18b20 will work again. But my installation is 500 km away so it's hard do a reset.

[loukote]

@Bajen2001, how do you power your uni plus - 12V?

Edited September 1 by loukote

[Bajen2001]

@loukote yes, 230V in the wall  to 12V supply

[loukote]

I hoped to hear from a wizard but for now i'm only speculating that the input power is just enough to power the shelly uni and not for the sensor. No idea if it's a plausible explanation or not...

[Jick]

Anyone have a solution to this? I just installed a Uni Plus with 5 temperature sensors (the plus should be able to handle 5 units). Upon boot, I see 3 sensors (not 5), of which 1 is showing regularly 'Null'. Then a bit later a temperature value is showed, but it fails quickly again.

Shelly uni plus is powered using a 5V DIN rail power supply. Running latest firmware.

Anyone ideas?

[wooly]

I never tried with 5 but with three i had similar problem and looked that sensors, when more than one, need a very perfect contact. check it first.