if(Serial) - Arduino Reference

if(Serial)

Description

Indicates if the specified Serial port is ready.

On the Leonardo, if (Serial) indicates whether or not the USB CDC serial connection is open. For all other instances, including if (Serial1) on the Leonardo, this will always return true.

This was introduced in Arduino IDE 1.0.1.

Syntax

All boards:

if (Serial)

Arduino Leonardo specific:

if (Serial1)

Arduino Mega specific:

if (Serial1)
if (Serial2)
if (Serial3)

Parameters

Nothing

Returns

boolean : returns true if the specified serial port is available. This will only return false if querying the Leonardo’s USB CDC serial connection before it is ready.

Example Code

void setup() {
 //Initialize serial and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB
  }
}

void loop() {
 //proceed normally
}