Fibaro Smart Implant and DS18B20


Does anybody now how to connect more then one DS18B20 to the Smart implant? I can connect one and it shows up fine in homey, but when I try to connect one more and add the device again none of the DS18B20 shows up :confused:


What I notice is that the amount of sensors you can add, depends on the length of the sensor cables but also on the power supply.

For example, I was able to add 5 sensors with cables of 3 meter, but not 3 sensors with cables of 10 meter.

Also using a power supply of 24V gives better results, with enough power of course.

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Some problem here. With two sensors I cannot even add the device.
Might be that the databus is not working correctly, as it needs an pull up resistor of 4,7k Ohm. I have to wait for the delivery of the resistor.

In the O P E R A T I N G M A N U A L is the next picture: ( No resistor mentioned )


With 2 sensors step 5 is not successful.
The 1st sensor has 1m cable, the 2nd 3 m.
I will test to connect the 3m sensor only.
The pull-up is for defining good signals on the databus. These signal, especially the high signal, will get worse with longer lines and multiple sensors.
So to exclude this possible cause, I will add this pull-up resistor.
By the way, a bus network is shown, but I made it a star. That also has its limitations, making a short bus with long stubs.
I will let you know the results.


i had this working with 4 sensors and a smart implant, you need to reset the devices and connect all the sensors and than pair the sensor like you normal do to homey, worked for my like this

After connecting the second sensor, pairing just fails. When I remove the second sensor, pairing is fine. I will just run some more test to find the problem.

Yes. But with removing the device it doesnt reset it self. You need to find a way to reset it and than pair it again

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I found the reset procedure on page 18 and will test it.

Thanks, It is now working with 2 sensors, 1 sensor with 1 meter cable and 1 sensor with 3 meter cable. I had to follow the procedure a few times. When paring the device, wait for the red led after the you pushed the button 3 times, before pushing the buttons 3 times fast again.

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