Connect temperature sensor and register measurements

DS18B20 Temperatuur sensor
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https://www.kernel.org/doc/Documentation/w1/w1.generic
If you have a w1 bus that never changes (you don't add or remove devices),
you can set the module parameter search_count to a small positive number
for an initially small number of bus searches. Alternatively it could be
set to zero, then manually add the slave device serial numbers by
w1_master_add device file. The w1_master_add and w1_master_remove files
generally only make sense when searching is disabled, as a search will
redetect manually removed devices that are present and timeout manually
added devices that aren't on the bus.

vi /boot/config.txt
dtoverlay=w1-gpio,gpiopin=4

cd /sys/bus/w1/devices
ls

cat /sys/bus/w1/devices/28*/w1_slave |grep "t=" |cut -d "=" -f 2 | awk ' { printf "%.1f" , $1 /1000 } '
cat /sys/class/thermal/thermal_zone0/temp | awk ' { printf "%.1f" , $1 / 1000 } '

Temperature stop searching for device changes (default -1) : echo "0" > /sys/bus/w1/devices/w1_bus_master1/w1_master_search