Arduino Reference

Serial.println()

Description

Prints data to the serial port as human-readable ASCII text followed by a carriage return character (ASCII 13, or '\r') and a newline character (ASCII 10, or '\n'). This command takes the same forms as Serial.print().

Syntax

Serial.println(val)
Serial.println(val, format)

Parameters

Serial: serial port object. See the list of available serial ports for each board on the Serial main page.

val: the value to print - any data type

format: specifies the number base (for integral data types) or number of decimal places (for floating point types)

Returns

size_t: println() returns the number of bytes written, though reading that number is optional

Example Code

/*
 Analog input reads an analog input on analog in 0, prints the value out.
 created 24 March 2006
 by Tom Igoe
 */

int analogValue = 0;    // variable to hold the analog value

void setup() {
  // open the serial port at 9600 bps:
  Serial.begin(9600);
}

void loop() {
  // read the analog input on pin 0:
  analogValue = analogRead(0);

  // print it out in many formats:
  Serial.println(analogValue);       // print as an ASCII-encoded decimal
  Serial.println(analogValue, DEC);  // print as an ASCII-encoded decimal
  Serial.println(analogValue, HEX);  // print as an ASCII-encoded hexadecimal
  Serial.println(analogValue, OCT);  // print as an ASCII-encoded octal
  Serial.println(analogValue, BIN);  // print as an ASCII-encoded binary

  // delay 10 milliseconds before the next reading:
  delay(10);
}

Notes and Warnings

For information on the asyncronicity of Serial.println(), see the Notes and Warnings section of the Serial.write() reference page.