Accessing the "user button" on the R4S

[getliquidsky]

Hi

I would like to know if anyone using Ubuntu has been able to access the "User Button"

http://stepx.io/downloads/UserButtonR4S.jpeg

I find no documentation how to interact with this button.
I am using ... Ubuntu Core with it.

If you have an idea how I can user python or so to detect when the button is pressed.

Thank you

R.

[v8dave]

Check the schematic to find out which GPIO pin it is connected to.