Push a button the first board and the other board's LED lights up. This is demonstrating basic 2-way networking over a serial bus, which I will use for communication in my final project.
The master board sends out a slave ID indicating that the slave should respond. The slave response is exactly one character at which point the master queries another slave.
Pretty basic circuits...
While things look basic this week, they'll be much more interesting when implemented with my final project, I promise.