An if statement allows you to choose between two discrete options, TRUE or FALSE. When there are more than two options, you can use multiple if statements, or you can use the switch statement. Switch allows you to choose between several discrete options.
This tutorial shows you how to use switch to turn on one of several different LEDs based on a byte of data received serially. The sketch listens for serial input, and turns on a different LED for the characters a, b, c, d, or e.
Circuit
Five LEDs are attached to digital pins 2, 3, 4, 5, and 6 in series through 220 ohm resistors.
To make this sketch work, your Arduino must be connected to your computer. Open the Serial Monitor, and send the characters a, b, c, d, or e, or anything else.
image developed using Fritzing. For more circuit examples, see the Fritzing project page
Schematic:
Code
/*
Switch statement with serial input
Demonstrates the use of a switch statement. The switch
statement allows you to choose from among a set of discrete values
of a variable. It’s like a series of if statements.
To see this sketch in action, open the Serial monitor and send any character.
The characters a, b, c, d, and e, will turn on LEDs. Any other character will turn
the LEDs off.
The circuit:
– five LEDs attached to digital pins 2 through 6 through 220 ohm resistors
created 1 Jul 2009
by Tom Igoe
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/SwitchCase2
*/