When working in Embrio you can connect directly to an Arduino to see the functionality of your program in real time. In the bottom left of the application is the Arduino Communication panel. If you don’t see the panel, you need to first install Arduino 1.6, then tell Embrio where you installed it.
To connect to you Arduino you simple select the model you are using, and the port that it is attached to, then click on the connection button. When there is no connection the icon looks like an unplugged socket, and it changes to a connected socket when there is a connection. To connect to and communicate with the Arduino, Embrio writes a little sketch that does all of the reading and writing to pins that are defined in your project and uploads it using the Arduino software. To the right of the icons is a message that shows the current status of the communicator.
While in connected mode, the Arduino reads values, sends them to the computer where they are displayed and passed through the rest of the nodes in your project, and then outputs are sent back to the Arduino for writing to pins. Note that this adds some delay to your project. When your final program is compiled and uploaded, all of the processing happens on the Arduino, so things are much faster. With most projects there isn’t much of a noticeable difference, but if you’re doing something that needs high levels of responsiveness and high refresh rates, you might want to do a full compile pretty often while you work to see how the real compiled program works.
Whenever you change a pin that touches a pin on the Arduino, like a controller input, controller output, or custom Arduino node, you need to refresh the connection program. When the program is in sync the refresh button next to the connect button is grayed out and cannot be clicked. When you make a change that requires a refresh the button becomes black.
The next two buttons have to do with compiling the full project to the Arduino. This feature is only available in the full version of Embrio, and is discussed further in another tutorial.