Serial.begin()

Description

Sets the data rate in bits per second (baud) for serial data transmission. For communicating with the computer, use one of these rates: 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, or 115200. You can, however, specify other rates - for example, to communicate over pins 0 and 1 with a component that requires a particular baud rate.

An optional second argument configures the data, parity, and stop bits. The default is 8 data bits, no parity, one stop bit.

Syntax

Serial.begin(speed) Serial.begin(speed, config)

Arduino Mega only:

Serial1.begin(speed)
Serial2.begin(speed)
Serial3.begin(speed)
Serial1.begin(speed, config)
Serial2.begin(speed, config)
Serial3.begin(speed, config)

Parameters

speed: in bits per second (baud) - long

config: sets data, parity, and stop bits. Valid values are

SERIAL_5N1
SERIAL_6N1
SERIAL_7N1
SERIAL_8N1 (the default)
SERIAL_5N2
SERIAL_6N2
SERIAL_7N2
SERIAL_8N2
SERIAL_5E1
SERIAL_6E1
SERIAL_7E1
SERIAL_8E1
SERIAL_5E2
SERIAL_6E2
SERIAL_7E2
SERIAL_8E2
SERIAL_5O1
SERIAL_6O1
SERIAL_7O1
SERIAL_8O1
SERIAL_5O2
SERIAL_6O2
SERIAL_7O2
SERIAL_8O2

Returns

Nothing

Example Code

void setup() {
    Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}

void loop() {}

Arduino Mega example:

// Arduino Mega using all four of its Serial ports
// (Serial, Serial1, Serial2, Serial3),
// with different baud rates:

void setup(){
  Serial.begin(9600);
  Serial1.begin(38400);
  Serial2.begin(19200);
  Serial3.begin(4800);

  Serial.println("Hello Computer");
  Serial1.println("Hello Serial 1");
  Serial2.println("Hello Serial 2");
  Serial3.println("Hello Serial 3");
}
void loop() {}

Thanks to Jeff Gray for the mega example