I have 3 pcs of DS18B20 sensors connected to Arduino with about 20 meter 3-wire cable to my DIY solar collector.
When all sensors were located onto the protoboard they worked fine and correct, but when connected with 20+ m
cable all temperature readings are all the time 0 degrees celsius? Must be because of the distance, but how can i help it ?
Did some searching about old messages and find one advice, so i did replac the 4k7
resistor with 2k2 and now it works fine ! No more 0-values, only correct ones 8)
What cable are you using?? I would suggest using CAT5 network cable, which has 4 twisted pairs. I would use one pair for +5V and Ground, and the other 3 pairs for DS18B20 Signal and Ground. That would be for the long run to your solar collector, and then break out to the individual sensors with 3-wire cable, or 2 twisted pairs. Keeping the Signal and Ground in twisted pair as far as possible would be good.