<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html> <head> <title>Arduino - Available </title> <link rel="shortcut icon" type="image/x-icon" href="http://arduino.cc/en/favicon.png"> <link rel='stylesheet' href='arduinoUno.css' type='text/css' /> <!--HeaderText--><style type='text/css'><!-- ul, ol, pre, dl, p { margin-top:0px; margin-bottom:0px; } code { white-space: nowrap; } .vspace { margin-top:1.33em; } .indent { margin-left:40px; } .outdent { margin-left:40px; text-indent:-40px; } a.createlinktext { text-decoration:none; border-bottom:1px dotted gray; } a.createlink { text-decoration:none; position:relative; top:-0.5em; font-weight:bold; font-size:smaller; border-bottom:none; } img { border:0px; } span.anchor { float: left; font-size: 10px; margin-left: -10px; width: 10px; position:relative; top:-0.1em; text-align: center; } span.anchor a { text-decoration: none; } span.anchor a:hover { text-decoration: underline; } ol.toc { text-indent:-20px; list-style: none; } ol.toc ol.toc { text-indent:-40px; } div.tocfloat { font-size: smaller; margin-bottom: 10px; border-top: 1px dotted #555555; border-bottom: 1px dotted #555555; padding-top: 5px; padding-bottom: 5px; width: 38%; float: right; margin-left: 10px; clear: right; margin-right:-13px; padding-right: 13px; padding-left: 13px; background-color: #eeeeee; } div.toc { font-size: smaller; padding: 5px; border: 1px dotted #cccccc; background: #f7f7f7; margin-bottom: 10px; } div.toc p { background-color: #f9f6d6; margin-top:-5px; padding-top: 5px; margin-left:-5px; padding-left: 5px; margin-right:-5px; padding-right: 5px; padding-bottom: 3px; border-bottom: 1px dotted #cccccc; }.editconflict { color:green; font-style:italic; margin-top:1.33em; margin-bottom:1.33em; } table.markup { border: 2px dotted #ccf; width:90%; } td.markup1, td.markup2 { padding-left:10px; padding-right:10px; } td.markup1 { border-bottom: 1px solid #ccf; } div.faq { margin-left:2em; } div.faq p.question { margin: 1em 0 0.75em -2em; font-weight:bold; } div.faq hr { margin-left: -2em; } .frame { border:1px solid #cccccc; padding:4px; background-color:#f9f9f9; } .lfloat { float:left; margin-right:0.5em; } .rfloat { float:right; margin-left:0.5em; } a.varlink { text-decoration:none; } --></style><script type="text/javascript"> function toggle(obj) { var elstyle = document.getElementById(obj).style; var text = document.getElementById(obj + "tog"); if (elstyle.display == 'none') { elstyle.display = 'block'; text.innerHTML = "hide"; } else { elstyle.display = 'none'; text.innerHTML = "show"; } } </script> <meta name='robots' content='index,follow' /> <meta name="verify-v1" content="TtxFIEJAB6zdJ509wLxjnapQzKAMNm9u0Wj4ho6wxIY=" /> </head> <body> <div id="page"> <!--PageHeaderFmt--> <div id="pageheader"> <div class="title"><a href='http://arduino.cc/en'>Arduino</a></div> <div class="search"> <!-- SiteSearch Google --> <FORM method=GET action="http://www.google.com/search"> <input type=hidden name=ie value=UTF-8> <input type=hidden name=oe value=UTF-8> <INPUT TYPE=text name=q size=25 maxlength=255 value=""> <INPUT type=submit name=btnG VALUE="search"> <input type=hidden name=domains value="http://www.arduino.cc/"> <input type=hidden name=sitesearch value="http://www.arduino.cc/"> </FORM> <!-- SiteSearch Google --> </div> </div> <!--/PageHeaderFmt--> <!--PageLeftFmt--> <div id="pagenav"> <div id="navbar"> <p><a class='wikilink' href='http://arduino.cc/en/Main/Buy'>Buy</a> <a class='wikilink' href='http://arduino.cc/en/Main/Software'>Download</a> <a class='wikilink' href='Guide_index.html'>Getting Started</a> <a class='wikilink' href='http://arduino.cc/en/Tutorial/HomePage'>Learning</a> <a class='wikilink' href='index.html'>Reference</a> <a class='wikilink' href='http://arduino.cc/en/Main/Hardware'>Hardware</a> <a class='wikilink' href='FAQ.html'>FAQ</a> </p> <p class='vspace'></p> </div> <div id="navbar_external"> <a class="urllink" href="http://www.arduino.cc/blog/" rel="nofollow">Blog »</a><a class="urllink" href="http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl" rel="nofollow">Forum »</a><a class="urllink" href="http://www.arduino.cc/playground/" rel="nofollow">Playground »</a> </div> </div> <!--/PageLeftFmt--> <div id="pagetext"> <!--PageText--> <div id='wikitext'> <p><a class='wikilink' href='Serial.html'>Serial</a> </p> <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() > 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> </p> </div> <!-- AddThis Button BEGIN --> <script type="text/javascript">var addthis_language = "en"; </script> <div class="addthis_container addthis_toolbox addthis_default_style" addthis:url="Serial_Available" addthis:title="Arduino Wiki English"> <a href="http://www.addthis.com/bookmark.php?v=250&username=arduinoteam" class="addthis_button_compact">Share</a><span class="addthis_separator">|</span><a class="addthis_button_email"></a><a class="addthis_button_favorites"></a><a class="addthis_button_print"></a><a class="addthis_button_facebook"></a><a class="addthis_button_twitter"></a><script type="text/javascript" src="http://s7.addthis.com/js/250/addthis_widget.js#username=arduinoteam"></script></div> <!-- AddThis Button END --> </div> <!--PageFooterFmt--> <div id="pagefooter"> ©Arduino | <a href=.html'Serial_Available?action=edit.html'>Edit Page</a> | <a href='Serial_Available?action=diff.html'>Page History</a> | <a href='Serial_Available?action=print.html' target='_blank'>Printable View</a> | <a href='http://arduino.cc/en/Site/AllRecentChanges'>All Recent Site Changes</a> </div> <!--/PageFooterFmt--> </div> </body> </html>