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
Getting Started With Using Serial Communication To Send Commands
ASCII Data and Using Markers to Separate Data
In the last post I briefly talked about different data formats and how I recommend keeping things as simple as possible. With this is mind for a first project let’s create a simple blinking LED. We will have one Arduino controlling an LED on a second Arduino. Controls to turn the LED on or off will be sent via serial from the first Arduino to the second Arduino. This is as basic as it gets. Arduino Blink by remote control. The LED has only two states so simple control codes can be used and to start I am using 1 of on and 0 for off.
In these examples I am using Arduino Nanos but any kind of Arduino can be used and for this series I am using Arduino to Arduino communication. The techniques are exactly the same for any UART to UART device. For example, in Arduino to Arduino by Bluetooth I use exactly the same serial communication techniques wirelessly over Bluetooth.