You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
104 lines
4.7 KiB
HTML
104 lines
4.7 KiB
HTML
15 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<title>Arduino - PulseIn </title>
|
||
|
|
<link rel='stylesheet' href='arduino.css' type='text/css' />
|
||
|
|
<meta name="verify-v1" content="TtxFIEJAB6zdJ509wLxjnapQzKAMNm9u0Wj4ho6wxIY=" />
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div id="page">
|
||
|
|
<!--PageHeaderFmt-->
|
||
|
|
<div id="pageheader">
|
||
|
|
<div class="title"><a href="http://www.arduino.cc"/>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" style="text-align: right">
|
||
|
|
<div style="float: left;">
|
||
|
|
<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>
|
||
|
|
<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>
|
||
|
|
<!--/PageLeftFmt-->
|
||
|
|
<div id="pagetext">
|
||
|
|
<!--PageText-->
|
||
|
|
<div id='wikitext'>
|
||
|
|
<p><strong>Reference</strong> <a class='wikilink' href='index.html'>Language</a> (<a class='wikilink' href='Extended.html'>extended</a>) | <a class='wikilink' href='Libraries.html'>Libraries</a> | <a class='wikilink' href='Comparison.html'>Comparison</a> | <a class='wikilink' href='Changes.html'>Changes</a>
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><h2>pulseIn()</h2>
|
||
|
|
<h4>Description</h4>
|
||
|
|
<p>Reads a pulse (either HIGH or LOW) on a pin. For example, if <strong>value</strong> is <strong>HIGH</strong>, <strong>pulseIn()</strong> waits for the pin to go <strong>HIGH</strong>, starts timing, then waits for the pin to go <strong>LOW</strong> and stops timing. Returns the length of the pulse in microseconds. Gives up and returns 0 if no pulse starts within a specified time out.
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><p>The timing of this function has been determined empirically and will probably show errors in longer pulses. Works on pulses from 10 microseconds to 3 minutes in length.
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><h4>Syntax</h4>
|
||
|
|
<p>pulseIn(pin, value) <br />pulseIn(pin, value, timeout)
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><h4>Parameters</h4>
|
||
|
|
<p>pin: the number of the pin on which you want to read the pulse. (<em>int</em>)
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><p>value: type of pulse to read: either <a class='wikilink' href='Constants.html'>HIGH</a> or <a class='wikilink' href='Constants.html'>LOW</a>. (<em>int</em>)
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><p>timeout (optional): the number of microseconds to wait for the pulse to start; default is one second (<em>unsigned long</em>)
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><h4>Returns</h4>
|
||
|
|
<p>the length of the pulse (in microseconds) or 0 if no pulse started before the timeout (<em>unsigned long</em>)
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><h4>Example</h4>
|
||
|
|
<pre>
|
||
|
|
|
||
|
|
int pin = 7;
|
||
|
|
unsigned long duration;
|
||
|
|
|
||
|
|
void setup()
|
||
|
|
{
|
||
|
|
pinMode(pin, INPUT);
|
||
|
|
}
|
||
|
|
|
||
|
|
void loop()
|
||
|
|
{
|
||
|
|
duration = pulseIn(pin, HIGH);
|
||
|
|
}
|
||
|
|
|
||
|
|
</pre>
|
||
|
|
<p class='vspace'></p><p><a class='wikilink' href='index.html'>Reference Home</a>
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><p><em>Corrections, suggestions, and new documentation should be posted to the <a class='urllink' href='http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?board=swbugs' rel='nofollow'>Forum</a>.</em>
|
||
|
|
</p>
|
||
|
|
<p class='vspace'></p><p>The text of the Arduino reference is licensed under a
|
||
|
|
<a class='urllink' href='http://creativecommons.org/licenses/by-sa/3.0/' rel='nofollow'>Creative Commons Attribution-ShareAlike 3.0 License</a>. Code samples in the reference are released into the public domain.
|
||
|
|
</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
</div>
|
||
|
|
<!--PageFooterFmt-->
|
||
|
|
<div id="pagefooter">
|
||
|
|
<a href='#'>Edit Page</a> | <a href='#'>Page History</a> | <a href='#' target='_blank'>Printable View</a> | <a href='http://arduino.cc/en/Site/AllRecentChanges'>All Recent Site Changes</a>
|
||
|
|
</div>
|
||
|
|
<!--/PageFooterFmt-->
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|