OH2: Netatmo binding and drawing charts

I’m running a Netatmo weather station and I successfully added it to my configuration.
Now I wanted to draw a chart for the temperature and the humidity, but no line is drawn.

I assume, the reason is the format of the values returned by the binding:
Temperature: "22.2 °C"
Humidity: “58 %”

The binding seems to return the values with the “°C” and “%” for better readability, but with these characters at the end, it’s no number anymore - and cannot be used for charts.

Now I’m a bit lost how and where to transform these values into “drawable” numbers.
Do I need rules for this? Or a REGEX at the item defintion?

Thank you for your help!

Forget it, found it out myself. For anyone else being as stupid as me:
I forgot the format definition at the items.

Instead of…

Number   Netatmo_WZ_Temperatur          "Temperatur [%.1f °C]"

I used…

Number   Netatmo_WZ_Temperatur          "Temperatur"

…which worked for the display, but not for the charts.

Just to make sure I understand, which is the correct way to define it? The first or the second (I would guess the second, but this seems to be contradicted by “which worked for the display, but not for the charts.”)


Sorry, if I was unclear - THIS is the version which works: