For demonstrating the benefits of the graphical approach let us study a very simple TinyOS application, one with a single user-defined component and three system components. Note that the real advantages of the visual environment can be recognized more easily with complex applications.

Our sample application, called BLINK, is part of the TinyOS release. It does not provide tremendous functionality: it blinks one of the LEDs at a given frequency. The configuration of the BLINK application (shown below) specifies the included components and the wiring (->) between the interfaces.

The Main component is contained in every application and its sole role is to initialize and start the application. We have wired these startup functions to our Blink component. Since our component requires access to the LedsC, we have made the appropriate links the LedsC system component. After initializing the SingleTimer component it will generate events periodically. These events are routed to the BlinkM component where the event handling routine will toggle the LED.

The interface of our Blink component can be easily defined now. From the wiring we know what kind of commands and events must be handled in our component and what other commands will be used by it. 

The graphical equivalent of the previous configuration files is shown in the figure below. It contains two module references  and two configuration references. The visual representation of the wiring is undeniably easier to comprehend. Another advantage of this graphical representation is the easy navigation through the component hierarchy. To double-click on a component's box GME opens it.