Communication with external processes in the embedded system can be accomplished in several ways. One approach that provides a strong API while maintaining a loose coupling for the implementation is to use Storyboard IO.

Storyboard IO is provided as a plugin for the Storyboard Engine and includes a C API and library for external applications to link against.

When the Storyboard IO plug-in is loaded a channel is created in order for processes to inject events into the system. A single event queue is used to serialize the events and therefore any events sent via Storyboard IO will be placed in the queue with standard Storyboard system events. If the external application wishes to receive events, it can create its own Storyboard IO channel which can have events sent through. Applications can have multiple receive channels and the Engine has a single input channel. The following diagram illustrates an application which can send events to the Engine and review events on a named channel.

The chapter Sending and Receiving Data with Storyboard IO discusses how to work with Storyboard IO to send and received events while the C API is covered in detail in the appendix Storyboard IO API.