having the same problem right now.
the dir /sys/bus/w1/devices doesn’t show anything, its empty.
maybe i did some wiring error, but i checked my wiring and did not discover any shortages or some other failure that far. tried with several ds18 b20 sensors without any success.
any ideas ?
the w1 kernel modules are loaded
i even tried with 2 pi’s. the new pi2 and the piB, tried different wiring schemes, different breadboards.
now this is far beyond me!