I had a Sonoff TH10 with a ds18b20 sensor that was included in the device. Everything was working properly. I decide to switch to a Shelly 1 V3 with temperature addon. I make the Shelly connection first. Everything’s fine. The problem comes when trying to connect the temperature addon. When stripping the wires from ds18b20 I see that the colors are red, black and yellow. I connect red to red, black to black, and white to yellow. When I connect the addon to Shelly, it stops working automatically, the IP web is not responding. If I disconnect the addon it works again. If I connect the addon again without the yellow cable, it doesn’t work either. If I connect the addon again without the three cables, it does work (only Shelly logically). Does anyone know what can happen? Is the sonoff ds18b20 not compatible? Thanks.
Check the resistance of the probe wires from red to yellow
I don’t understand much about electricity. This is my first time using a multimeter. If I choose ohm measurement mode and wire red and white, multimeter shows 54.2 and letter k. What does that mean?
The reading indicates 54200 ohms of resistance to current flow, the reason I asked is because the probes for the sonoff and the shelly may have the same sensor inside, but one may have a resistor inside the probe and the other may not.
I can compare your reading to the probe included with the shelly temp addon
Okay, I would appreciate it. I would like to know where the fault is to replace the probe, the addon or the Shelly 1. Although I suppose that probe of the Shelly and probe of the Sonoff should be the same, they both indicate that they use the DS18B20 probe.
I just checked 2 of the Shelly probes:
Hot to Gnd 3.20 MΩ ± 0.05 MΩ
Sig to Gnd 2.80 MΩ ± 0.05 MΩ
Hot to Sig Open (infinite resistance)
Where 1 MΩ = Mega Ohms (1000 KΩ)
Where hot is red, sig is yellow/white, gnd is black
I had to change the polarity to get measurements to ground, so there are diodes in the circuit
HOWEVER that did not yield resistance from hot to sig on either probe
54 KΩ is really low if there is no resistor, and really high if there is, since they usually use a 4.7 KΩ to 10.0 KΩ resistor
The Shelly probes should not have one, since the addon is designed to use multiple probes, so the resistor is in the addon itself (I think), though I was unsure what the natural hot to sig resistance was without the resistor, and it appears that is very high or infinite
Thank you very much, Richie. It is not clear to me, what do you think is my problem? The probe? The cable is 15 meters long, I do not know if that influences
my cable is maybe 2m max, a longer cable will increase the resistance a bit, but will not lower it.
I am not sure if the probe is bad, or if it has an extra resistor, or what.
I would double check the red/black and yellow/black resistance just for a point of reference, but I would not expect it to work given your red/yellow measurement… at least using only my probes as a comparison point
It is possible the reduced resistance is “sinking” power from the shelly causing it to freeze, I do not know, but the other measurements will paint a better picture
Hi,
How do I get the temperature addon and the temperature sensor to work with Shelly 1?
Regards
I didn’t do anything special to make it work. I just plugged it in a day after a long time and it worked. Maybe a bad wiring connection? I don’t know.