Get the number of bytes (characters) available for reading over the serial port.
None
The number of bytes are available to read in the serial buffer, or 0 if none are available. If any data has come in, Serial.available() will be greater than 0. The serial buffer can hold up to 128 bytes.
int incomingByte = 0; // for incoming serial data
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 0) {
// read the incoming byte:
incomingByte = Serial.read();
// say what you got:
Serial.print("I received: ");
Serial.println(incomingByte, DEC);
}
}
Serial.available has a documented bug in it in Arduino v.0007. This will be patched in v.0008, but see this thread if you wish to patch Serial.available in Arduino 0007.