You haven't directly made use of the serial communication between the host computer and the Arduino board. First, I'll describe how to write a basic client/server style program.

The official Arduino Blog has this week featured a new project which demonstrates ultrasonic Arduino to Arduino communication by Brazilian maker Eduardo Zola. Showing that you can communicate ...

The Arduino ecosystem is an amazing learning tool, but even those of us who love it admit that even the simplified C Arduino ...

Once you’ve completed [Jethomson’s] modifications to the cable you can follow his examples for using this in conjunction with an Arduino.