Sets the data rate in bits per second (baud) for serial data transmission. For communicating with the computer, use one of these rates: 300, 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.
int datarate, in bits per second (baud)
nothing
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