Digital I/O

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

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Ethernet
Ethernet (Server)
Ethernet (Client)
Servo Motor
Character LCD
SPI
I²C (Wire)
SD Card
SD (File Operations)
Periodic Operation
Clock (RTC)

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 set
mode: INPUT or OUTPUT

Returns

None

digitalWrite

Description

Write a HIGH or a 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 pin number

Returns

HIGH or LOW

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Sample for digitalWrite and digitalRead.

#include <Arduino.h>
#define INTERVAL 100
    
void setup()
{
    pinMode(PIN_LED_RED   , OUTPUT);
    pinMode(PIN_LED_GREEN , OUTPUT);
    pinMode(PIN_LED_BLUE  , OUTPUT);
    pinMode(PIN_LED_USER  , OUTPUT);
    pinMode(PIN_SW        , INPUT);
}
    
void loop()
{
    while(digitalRead(PIN_SW) == 0){
        digitalWrite(PIN_LED_USER, 1);
        delay(INTERVAL);
        digitalWrite(PIN_LED_USER, 0);
        delay(INTERVAL);
    }
    digitalWrite(PIN_LED_RED, 1);
    delay(INTERVAL);
    digitalWrite(PIN_LED_RED, 0);
    digitalWrite(PIN_LED_GREEN, 1);
    delay(INTERVAL);
    digitalWrite(PIN_LED_GREEN, 0);
    digitalWrite(PIN_LED_BLUE, 1);
    delay(INTERVAL);
    digitalWrite(PIN_LED_BLUE, 0);
    
}