Problem with 1-wire (CRC-error)

[Gast]

Hi,

I encounter some stability issues with the temperature (DS18B20) sensors on Loxone. Sometimes no values are returned (several of the sensors).
When looking at the 1-wire monitor I see several CRC errors followed by an valid value. See below . Anyone knows what may be the cause?

[Thomas M.]

This error also ocurred at my setup ...

- I had a 10B20 fixed into a heat shrink tube under water for measuring the rain water temp. This doesn't work, so water gets in.
suddenly (but after some months) CRC errors ...

- at installation i connected one 18B20 and 2401, next window one 18b20 and one 2401, ... suddenly the bus was too long and there the CRC errors ocurred.

- as i mentioned ... i had 2401. suddenly the 1-wire bus was faulty (don't know why - 3 years everything was ok), windows were recognized as open - 5 seconds later closed, ... (but no CRC errors).
I changed every 2401(DQ and GND) to 2411 (DQ, GND and 5V), problem solved.

So i hat three different problems which ended in CRC errors.

[Gast]

Thanks Thomas,

So far as I'm aware of - not using the 2401 at all. Will start reconeccting them one by one and check which one causes the error.

[manalishi]

Hi,

I encounter some stability issues with the temperature (DS18B20) sensors on Loxone. Sometimes no values are returned (several of the sensors).
When looking at the 1-wire monitor I see several CRC errors followed by an valid value. See below . Anyone knows what may be the cause?

Did you solve the issue? I have the same behavior.

[Labmaster]

Usualy CRC Errors on the 1-Wire bus reflects an overall unstable electrical bus system.
If the bus is already working on the edge (to long, to many clients, bad cabling ....) beween working/not working, then even very small changes (temperature, sensor or cable or contact aging) could make the difference.

Analog Device has a quit good writing about the 1-Wire bus check https://www.analog.com/en/resources/...-networks.html