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<p><a class='wikilink' href='Serial.html'>Serial</a>
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<p class='vspace'></p><h2>available()</h2>
<h4>Description</h4>
<p>Get the number of bytes (characters) available for reading from the serial port.  This is data that's already arrived and stored in the serial receive buffer (which holds 128 bytes).
</p>
<p class='vspace'></p><h4>Syntax</h4>
<p>Serial.available()
</p>
<p class='vspace'></p><p><em>Arduino Mega only:</em> <br />Serial1.available() <br />Serial2.available() <br />Serial3.available()
</p>
<p class='vspace'></p><h3>Parameters</h3>
<p>none
</p>
<p class='vspace'></p><h4>Returns</h4>
<p>the number of bytes available to read
</p>
<p class='vspace'></p><h3>Example</h3>
<pre>
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() &gt; 0) {
		// read the incoming byte:
		incomingByte = Serial.read();

		// say what you got:
		Serial.print("I received: ");
		Serial.println(incomingByte, DEC);
	}
}

</pre>
<p class='vspace'></p><p><strong>Arduino Mega example:</strong>
</p>
<p class='vspace'></p><pre>
void setup() {
  Serial.begin(9600);
  Serial1.begin(9600);

}

void loop() {
  // read from port 0, send to port 1:
  if (Serial.available()) {
    int inByte = Serial.read();
    Serial1.print(inByte, BYTE); 

  }
  // read from port 1, send to port 0:
  if (Serial1.available()) {
    int inByte = Serial1.read();
    Serial.print(inByte, BYTE); 
  }
}

</pre>
<p class='vspace'></p><h4>See also</h4>
<ul><li><a class='wikilink' href='Serial_Read.html'>Serial.read</a>()
</li><li><a class='wikilink' href='Serial_Flush.html'>Serial.flush</a>()
</li></ul><p class='vspace'></p><p><a class='wikilink' href='index.html'>Reference Home</a>
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