DS18B20 temperature sensors on Raspberry Pi to monitor air condition

configure kernel module

There are two ways to configure onewire kernel module, one is to use /boot/config.txt and add following line:

# IO1 on board
dtoverlay=w1-gpio,gpiopin=17

Another way to to use configfs and load device tree overlay in runtime:

pi@pihdmi:~/rpi-ds18b20 $ ./overlay-load.sh ./w1-2.dts

If you are loading device tree on runtime, you will have to add it to startup script like /etc/rc.local. This might allow you to have multiple onewire buses on single machine which will be enumerated in correct order (otherwise, there are ordered by number of gpio pin, which might not be something which suits your configuration).

add mapping between sensor id and name

Run w1-ds18b20.sh to figure out sensor id:

pi@pihdmi:~/rpi-ds18b20 $ ./w1-ds18b20.sh
28-03150505eeff  33.000

Now add mapping between sensor id and name into id2name.txt

pi@pihdmi:~/rpi-ds18b20 $ grep 28-03150505eeff id2name.txt
28-03150505eeff pihdmi

Now when you re-run script you will see name displayed:

pi@pihdmi:~/rpi-ds18b20 $ ./w1-ds18b20.sh
28-03150505eeff pihdmi 33.437

add systemd service to start automatically

Scripts are configured to work for our setup, to make it work in your environment you will need to edit IP address of influxdb server which is 10.60.0.92 in our examples in both rpi-ds18b20.service and w1-ds18b20-influx.sh

pi@pihdmi:~/rpi-ds18b20 $ sudo cp rpi-ds18b20.service /etc/systemd/system
pi@pihdmi:~/rpi-ds18b20 $ sudo systemctl enable rpi-ds18b20.service
pi@pihdmi:~/rpi-ds18b20 $ sudo systemctl start rpi-ds18b20.service