Steinberg CC121 is a compact control surface originally designed for use with the Cubase™ digital audio workstation.
Plug the USB cable from the CC121 into a USB2 or USB3 port on your computer. The device will be automatically recognized by your operating system and will appear in any of the lists of possible MIDI ports in Ardour.
To connect the CC121 to Ardour, open the Preferences dialog, and then click Control Surfaces. Tick the Enable checkbox opposite to "Steinberg CC121" to activate Ardour's CC121 support.
Once the device is activated, click Show Protocol Settings and in the newly opened window select the device in the drop-down lists for incoming and outgoing MIDI events.
Once you select the input and output port, Ardour will initialize CC121 and it will be ready to use. You only need do this once: once these ports are connected and your session has been saved, the connections will be made automatically in this and other future sessions.
Ardour supports a subset of features available in the CC121. Various actions in the program can be mapped to the following buttons and encoders on the device: