False values from DS18b20

Tanmay · February 15, 2025, 5:32pm

Hi Everyone,
I am working on an IOT monitoring system and using FMB120 with Dallas DS18b20 for monitoring Temperature.
However I am facing issues with the sensor and its readings in teltonika configurator.
The first sensor worked for some 5 minutes then it stopped working.
I used the second, It is giving a fixed value of 3000 degrees Celcius no matter what temperature I’m changing on it.
however, the same sensor works flawlessly with ESp32 or Arduino.

I am starting to speculate something has gone bad with the FMB120 itself. How do I pinoint this issue.

The sensor is generic DS18B20 from a local store

Patrick_Sangalang · February 16, 2025, 1:35pm

Hello @Tanmay,

Welcome to the Teltonika community forum!

Have you followed the wiring diagram for the FMB120 with a 1-wire Temperature sensor? If not, you may refer to this link https://wiki.teltonika-gps.com/view/1-Wire_Temperature_Sensors

On the other hand, the 3000 value was an error code from the device. (see screenshot below for additional information)

I hope this helps.

Best regards,
Patrick