Small example program that demonstrates enumerating temperature sensors and reading temperatures.
First, make sure Pico-SDK is installed and setup correctly ($PICO_SDK_PATH environment variable set).
Build steps (assuming using a Pico W):
$ cd example
$ mkdir build
$ cd build
$ cmake -DPICO_BOARD=pico_w ..
$ make
Example console output from the example program running on a Pico that has three DS18B20 sensors connected to it (with 4.7K pullup between data pin and 3.3V).
BOOT
[ 0.252490][ 252] Check for device(s) in the bus...
[ 0.256145][ 3] 1 or more devices detected.
[ 0.259940][ 3] Checking for devices using phantom power...
[ 0.268210][ 8] No devices using phantom power found.
[ 0.271739][ 3] Send Read ROM Command...
[ 0.282013][ 10] Read ROM Failed (multiple devices in the bus?)
[ 0.285675][ 3] start loop
[ 0.288972][ 3] Find devices in the bus...
[ 0.337435][ 48] 3 device(s) found.
[ 0.338713][ 1] Device 01: 2882126b00000061
[ 0.343454][ 4] Device 02: 28821e6a000000cf
[ 0.348227][ 4] Device 03: 2871d86a0000005a
[ 0.352988][ 4] Convert temperature: all devices
[ 0.360252][ 7] Wait for temperature measurement to complete (750ms)...
[ 1.115440][ 755] Wait done.
[ 1.127281][ 11] Device 2882126B00000061: temp: 24.5000C
[ 1.141523][ 14] Device 28821E6A000000CF: temp: 24.2500C
[ 1.155743][ 14] Device 2871D86A0000005A: temp: 37.6250C
[ 1.158877][ 3] sleep...
[ 11.162002][ 10003] Find devices in the bus...
[ 11.207650][ 45] 3 device(s) found.
[ 11.208909][ 1] Device 01: 2882126b00000061
[ 11.213670][ 4] Device 02: 28821e6a000000cf
[ 11.218444][ 4] Device 03: 2871d86a0000005a
[ 11.223200][ 4] Convert temperature: all devices
[ 11.230463][ 7] Wait for temperature measurement to complete (750ms)...
[ 11.985614][ 755] Wait done.
[ 11.997205][ 11] Device 2882126B00000061: temp: 24.4375C
[ 12.011424][ 14] Device 28821E6A000000CF: temp: 24.2500C
[ 12.025637][ 14] Device 2871D86A0000005A: temp: 37.6875C
[ 12.028770][ 3] sleep...