You can extend mono using the two options:
Making your own accessories for Mono matters very much for us. Therefore we have selected the standard 3.5 mm jack connector with 4 terminals, for a number of reasons: It is small, durable, available and pretty – compared to other connectors.
The 4 terminals in the 3.5 mm jack connector, will contain the following signals:
Mono’s 3.5mm jack provide both digital and analog I/O, but also power. You can configure the connectors I/O pins in software, making the use of the connector extremely flexible.
The expansion connector is a fine pitched 50-pin connector. It is hidden inside the plastic casing by default. You expose it by removing a small area of the plastic, guided by recess lines in the back panel.
When the connector is exposed it can be used together with our Arduino Shield Adaptor or you can build your own custom hardware. The connector contains all the signals found in the standard Arduino Uno pinout.
We will provide a complete diagram of all the signals in the connector, as soon as our design is frozen.
To enable compatibility with existing Arduino shields we have made a shield adaptor, utilizing the expansion connector. With the adaptor to have access to the same set of pins and the Arduino Uno, SPI, GPIO, analog, etc.
For flexibility you can attach mono to both sides of the Shield Adaptor PCB, as seen in the illustration below.