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().


Serial.println(val, format)


  • 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)


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


  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:
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:

See also

Language Reference Home

The text of the 86Duino reference is a modification of the Arduino reference and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.

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