This page has been updated. Please see the following newer guides:
Introduction, Using The Serial Monitor, and More
A Look at the Different Serial Libraries
Serial Commands Explained
Serial Data
Getting Started With Using Serial Communication To Send Commands
ASCII Data and Using Markers to Separate Data
In part 3 we sent and received single characters to control LEDs using a fairly simple technique. If all you need is to remotely turn a few things on and off then this method is probably the best. It is simple, easy to program, and reliable. Sometimes though single characters are not enough and we need to use more complex commands or we may want to send sensor data that comprises more than one character.
In this post I look at a few different techniques for sending complex data and commands; starting with functions that are built in the Arduino language and moving to our own functions that, IMHO, perform better and allow for better code.