pinMode()

[Digital I/O]

void pinMode(unsigned short pin, unsigned short mode);

Description

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

It is possible to enable pull-up resistors with the mode INPUT_PULLUP. Additionally, alternative output modes are available for all pins, such as THREE_STATE, OPEN_DRAIN, and OPEN_COLLECTOR.

Parameters

pin: the Custom Element pin.

mode: INPUT, OUTPUT, INPUT_PULLUP, THREE_STATE, OPEN_DRAIN, or OPEN_COLLECTOR

Returns

Nothing.

Example Code

The code makes the digital pin 7 an OPEN_COLLECTOR output and toggles it by alternating between HIGH and LOW at one second pace.

void setup() {
  pinLabel(7, "OUT");           // sets the pin 7 label to "OUT"  
  pinMode(7, OPEN_COLLECTOR);   // sets the digital pin 7 as OPEN COLLECTOR output
}

void loop() {
    // Remember that the pin is an OPEN COLLECTOR output, 
    // so it will only pull the voltage down
    
    digitalWrite(7, HIGH);   // sets the digital pin 7 to HIGH
    delay(1000);             // waits for a second
    digitalWrite(7, LOW);    // sets the digital pin 7 to LOW
    delay(1000);             // waits for a second
}

Notes and Warnings

All the pins can be used as digital pins, except for the power and ground pins.