Hi Guys,
Got a Fibaro FGBS-222. Wanted to hook up three temperature sensors to it. Even though Fibaro manual say the temperature sensor is DS18B20 but when I paired the device it shows DS18S20 as a device in drop down menu as shown. So I bought DS18S20. Looks like it does support DS18S20. Now the issue is it cannot read more than one external sensor. One sensor works fine. Any thoughts before I buy DS18B20 to try? I have not installed any separate drivers. Hubitat detected the Fibaro upon inclusion and show all the I/O devices.
I have scoped the data line of DS18S20 and the data look healthy. Initially I thought the cable length may be too long, at 8ft. Adding a sensor does not change signal quality. So signal quality looks good. Power source is 12V 3A. That is plenty of power.
Just checked the Amazon order. I did order DS18B20. So I guess I am not sure why is Fibaro showing DS18S20 in dropdown menu and not DS18B20? The devices are different in the sense that S is 9-bit only and B can do upto 12-bit.
Now checking the events shows only 1 out of 5 sensors logging temperature events when individually connected for testing. Others read temperature twice and never log an event after it. So it looks 4 out of 5 sensors are bad. Little less likely but that is what it looks like so far.
Interesting, I never noticed the HE driver drop down listing DS18S20. I also bought and installed 2-DS18B20. I get readings from both probes and the setup has been working for over a year. You should be good to go with good sensors. You will have to exclude the Fibaro FGBS-222 and then include again with good sensors.
I use this for myself, with 4 sensors. Over the years the sensors may go bad, but in your case, are you sure that the are connected correctly? The three pins need to be connected the same on all, and in a specific way.
Yes, the connections are good. I order the sensors from Amazon about 8 months ago. Just gotten around to work on them now. I did two iteration of the cabling. In the first iteration I hooked three of them with each having 8 ft cable. It ended up reading only one sensor out of the three. The cable looked long so I though it may be corrupting the signal due to longer stub length. So I did a second iteration with six ft cable with shorter stubs. The results were same. Only one sensor worked. So this time I probed it further. With one sensor working I saw the waveform on data line. It looked quite good. Nice sharp square wave with proper logic highs and lows. Then I added second sensor on the harness. The data looked good but the second sensor would not read properly. So at this point I removed the working sensor and started trying rest of 4 sensors one at a time. Each of the four sensors will not read temperature. But when I put back the know good sensor it worked again on same harness. I also added an external 4.7K pull up on the data line to see if that will work. But no change. It looks like Fibaro already has an oboard pull up as per datasheet connection diagram. So it was not that the sensors did not liked long length or multiple of them on same bus. It was more like 4 of the senors are bad it appears. I cut open one of the sensors but I do not see a DS18B20 in them. These are placed in a epoxy filled metal tube. It appears like it is third party die placed in epoxy. Attached is a cutaway. I was expecting a TO-92 package but there is metal strip on the left cutaway and three wires on right cutaway but no TO-92. So my guess is these are counterfeit parts being sold on Amazon as DS18B20. If they are selling 5 of these with 3 ft cable for $10 and actual part on Digikey costs close to $5 then there is something fishy about them. I ordered another batch before the tear down to try my luck on new vendor. Lastly if this did not work I will try buying the actual part, DS18B20 in TO-92 package, from Digikey and try it.
Before there was an built-in driver, I was using a community one. With that driver (and possibly the built-in one), you needed to have all sensors connected before adding/pairing the device to the hub. Else it would not pick up the additional sensors. I.e. try removing and pair again with all sensors attached.
i have two implants now with 5 & 6 DS18b20 on and they work pretty much faultless except if they read 10, 20, 30, 40, 50, 60 DegC exactly they come up with some weird code but as soon as it goes over/under reads just find
