Fibaro Universal Sensor Temperature Zero

[vettori 0]

Hello,

I have a Fibaro Universal Sensor connected only to a DS18B20 temperature sensor (metal case with cable, purchased on Amazon). The HCL recognizes the universal sensor and shows three devices, two motion sensor and a temperature.

The problem is that the temperature is always zero.

 

Can you suggest a fix ? If the DS18B20 wires are not connected the right way, would I see a zero or no temperature sensor at all ?

 

I already tried to remove from the network and re-add it.

 

Thank you

[j.nowacki 5]

First make sure wires are not too long or placed along the mains grid. PSU can also be a source of the problem, please try out some better stabilized to make sure it is not the reason - like the laptop one.

[vettori 0]

First make sure wires are not too long or placed along the mains grid. PSU can also be a source of the problem, please try out some better stabilized to make sure it is not the reason - like the laptop one.

 

 

Wires are just 15 cm long and at the moment the sensor, module and power unit are on a table

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To power the sensor I'm using a LED driver, 250V ac -> 12V dc, 6W max. I need something very small and thin. Do you think this can be the problem ?

Thanks

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[j.nowacki 5]

I have seen DS18B20 sensors not working properly due to "noisy" PSU, of course cause may be different but give another PSU a try.

[Cyberhofi 0]

I have the same problem. I connected 4 temperature sensors to the Universal Sensor (3x 1m ane 1x 11m cable length).

Because i hade issues with noisy Power supplies i hooked it up to a 12V lead acid Battery, also the 11m cable is shielded and all cables are away from mains cables.

 

After inclusion it worked and read the correct temperatures but did not get new values. So i disconnected the power and reconnected it.

Now im getting 0°C redings on every Sensor - do you have any suggestions?

 

 

By the way: Please consider a (better)input filter at the power input if you do a redesign of this unit. Im a development enigieer for electronics and a device whitch is this sensitive to the power supply is an absolute no-go in automation devices. Also a noisy PSU should not be a problem for the DS18B20 sensors because these use the Voltage regulator on YOUR device - so maybe its a grounding issue in the design and not the users fault.

 

Edit: I tried adding a bypass cap to the farest sensor but it did not help

[killer8 0]

I had the same problem and finally fixed it with the help of fibaro support. I explained the solution here 

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