This is a preview version of the DisplayLink DL-7450 Software Development Kit Documentation. The functionality that is described and made available in this version is subject to addition, removal or change without warning.

Programming paradigm

When executing code on the DL-7450, the application runs using a single thread of execution. Whilst this thread (henceforth called the Python thread) executes, there are a number of actions that cannot be performed:

• The execution of any callbacks, whether they are timers set via wakeup(), responses from async http requests or responses to changes in the state of DL-7450 hardware (e.g. gpio pins).

• The rendering of elements added, removed or modified on the splashscreen.

The use of time.sleep therefore is highly discouraged, as it will prevent any of these core SDK functionalities from occuring.

Instead, application developers are encouraged to write applications that react to events, using the main component of the app mostly to set up wakeup.Timers and other callbacks.

Once the Python thread finishes processing the Python code, it is now able to go idle and allow timers, callbacks and rendering to occur.

The use of dedicated callbacks where available is also highly encouraged over proactively polling state using a wakeup.Timer; this will result in much more responsive applications.