Customer:
I need help with temperature monitoring. We extended the DS18B20 temperature sensor wire by 12 m (6-core shielded cable, 0.22 mm²) and connected it to a GPS/GSM device so we can read the temperature via a web application.
For a while the temperature readings are correct, then it starts showing only 0.0°C, then it works again, and at one point the device sent a constant temperature of 18.2°C for 9 hours before dropping back to 0.0°C and then working correctly again, and so on.
Do you have any idea what the problem might be and how to fix it?
Original message (Croatian)
Molio bih pomoć na temu praćenja temperature.
Žicu od senzora temperature DS18B20 smo produžili za 12 m (kabel sa 6 vodiča 0,22mm2, oklopljeni) i spojili na gps/gsm uređaj tako da preko web aplikacije možemo očitavati temperaturu.
Ukratko, neko vrijeme stižu prave informacije o temperaturi i onda se počne prikazivati samo temp. 0,0°C, pa opet sve bude ok, a onda je u nekom trenutku 9h uređaj slao konstantno temp. od 18,2°C da bi opet pala na 0,0°C pa opet sve radi ok itd.
Imate li kakavu ideju u čemu je problem i kako da ga riješimo?
Hvala
Originally submitted via email support on 27 January 2016. Migrated to the forum for community visibility.