Arduino-Digital I/O Function

This article details the use of Arduino's Digital I/O functions.

The Digital I/O functions allow the Arduino board to output and input digital signals.

For other Arduino functions and libraries, please refer to the following article.

Digital I/O Functions

Functions	Parameters	Returns	Explanation
void pinMode(pin, mode)	pin: The digital pin number to set mode: INPUT, OUTPUT, or INPUT_PULLUP	None	Configures the pin to be input, output, or pullup
void digitalWrite(pin, value)	pin: The digital pin number to set value: HIGH or LOW	None	Write HIGH or LOW to the digital pin
int digitalRead(pin)	pin: The digital pin number to set	HIGH or LOW	Reads HIGH or LOW from the digital pin

pinMode()/Configures the pin to be input, output, or pullup

The pinMode() function switches the mode of digital I/O by setting "pin number" and "mode" as parameters.

The mode can be selected from "INPUT", "OUTPUT", and "INPUT_PULLUP".

digitalWrite()/Write HIGH or LOW to the digital pin

The digitalWrite() function performs digital output by setting "pin number" and "output voltage" as parameters. The output voltage can be "HIGH" or "LOW".

digitalRead()/Reads HIGH or LOW from the digital pin

The digitalRead() function is used to perform digital input by setting a "pin number" as an parameter.

The input voltage status returns "HIGH" for 5V and "LOW" for 0V.

Sample Programs (Sample Sketches)

Sample programs that use Digital I/O functions to move electronic parts such as LEDs and switches are introduced.

LED (Light Emitting Diode)

Blinking LED is programmed in the Digital I/O functions.

Switch

The input state of the switch is read by a program using Digital I/O functions.