Digital I/O

Digital I/O
Analog I/O
Advanced I/O
Time
Math
Trigonometry
Random Numbers
Bits and Bytes
Interrupts
Serial Comm.

Ethernet
Ethernet (Server)
Ethernet (Client)
Servo Motor
Stepping Motor
Character LCD
EEPROM
SPI
I²C (Wire)
SD
SD (File Operations)
Image Processing
Periodic Operation
Clock (RTC)
Utility

This library is for configuring the digital signal (HIGH/LOW) to function as either input or output.

pinMode

Description

Configures the specified pin to behave either as an input or an output.

Syntax

pinMode(pin, mode)

Parameters

pin: The number of the pin to be set.
mode:
   INPUT
   OUTPUT
   INPUT_PULLUP (pullup then input)
   OUTPUT_HIGH (enable 2 times current)
   OUTPUT_OPENDRAIN

Returns

None

digitalWrite

Description

Writes a HIGH or LOW value to a digital pin.

Syntax

digitalWrite(uint8_t pin, uint8_t value)

Parameters

pin: The pin number
value: HIGH or LOW

Returns

None

digitalRead

Description

Reads the value from a specified digital pin, either HIGH or LOW.

Syntax

digitalRead(uint8_t pin)

Parameters

pin: The number of the digital pin you want to read

Returns

HIGH or LOW

Sample for digitalWrite and digitalRead.

#include <Arduino.h>
void setup()
{
    pinMode(PIN_LED0, OUTPUT);
    pinMode(PIN_LED1, OUTPUT);
    pinMode(PIN_SW, INPUT);
}
  
void loop()
{
    if(digitalRead(PIN_SW) == 0){
        digitalWrite(PIN_LED0, HIGH);
        digitalWrite(PIN_LED1, LOW);
    } else {
        digitalWrite(PIN_LED1, HIGH);
        digitalWrite(PIN_LED0, LOW);
    }
}