Strange Behavior on DS18B20 Temp sensor and Pull-up Resistor

[MarkT]

@zeronix

I´m testing Arduino uno with 7 temperature sensors for a composting project , all worked good until i add more than 2 sensors :).

Make sure every sensor has a decoupling capacitor between Vcc and ground. With a large breadboard setup I'd worry about wiring integrity - recheck every connection.