432 lines
23 KiB
HTML
432 lines
23 KiB
HTML
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<?xml version="1.0" encoding="utf-8"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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<html xmlns:MadCap="http://www.madcapsoftware.com/Schemas/MadCap.xsd" MadCap:lastBlockDepth="6" MadCap:lastHeight="94" MadCap:lastWidth="853" MadCap:disableMasterStylesheet="true" MadCap:tocPath="" MadCap:InPreviewMode="false" MadCap:PreloadImages="false" MadCap:RuntimeFileType="Topic" MadCap:TargetType="WebHelp" lang="en-us" xml:lang="en-us" MadCap:PathToHelpSystem="../../../" MadCap:HelpSystemFileName="Default.xml" MadCap:SearchType="Stem">
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<head><title>OWIN</title>
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<link href="../../SkinSupport/MadCap.css" rel="stylesheet" />
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<link href="../../Resources/Stylesheets/BSE_Help.css" rel="stylesheet" />
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<script src="../../SkinSupport/MadCapAll.js" type="text/javascript">
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</script>
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</head>
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<body>
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<h1 class="code">OWIN</h1>
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<div class="ImagePlusCaption">
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<div class="Col2">
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<p>
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<img src="../../graphics/pgm_icon2p.gif" border="0" alt="BS2p icon" title="BS2p icon" />
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<img src="../../graphics/pgm_icon2pe.gif" border="0" alt="BS2pe icon" title="BS2pe icon" />
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<img src="../../graphics/pgm_icon2px.gif" border="0" alt="BS2px icon" title="BS2px icon" />
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</p>
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</div>
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<p style="text-align: right;"><a href="../ExampleTopics/OwinOwoutEx.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">OWIN / OWOUT Example</a>
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</p>
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<p> </p>
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</div>
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<p class="clear"> </p>
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<p> </p>
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<p class="PlainText">Syntax: <span class="keyword_in_text">OWIN</span> <![CDATA[ ]]><i>Pin</i>,<i> Mode</i>, [<i>InputData</i>]</p>
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<h2>Function</h2>
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<p>Receive data from a device using the Maxim/Dallas Semiconductor 1-Wire<sup>®</sup>protocol.</p>
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<ul>
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<li value="1"><b><i>Pin</i></b> is a variable/constant/expression (0 - 15) that specifies
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which I/O pin to use. 1-Wire devices require only one I/O pin
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(called DQ) to communicate. This I/O pin will be toggled between output
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and input mode during the <span class="keyword_in_text">OWIN</span> command and will be set to input mode
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by the end of the <span class="keyword_in_text">OWIN</span> command.</li>
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<li value="2"><b><i>Mode</i></b> is a variable/constant/expression (0 - 15) indicating
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the mode of data transfer. The <i>Mode</i> argument controls placement of
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reset pulses (and detection of presence pulses) as well as byte vs. bit input
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and normal vs. high speed. See explanation below.</li>
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<li value="3"><b><i>InputData</i></b> is a list of variables and modifiers that tells
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<span class="keyword_in_text">OWIN</span> what to do with incoming data. <span class="keyword_in_text">OWIN</span> can store data in a
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variable or array, interpret numeric text (decimal, binary, or hex) and store
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the corresponding value in a variable, wait for a fixed or variable sequence
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of bytes, or ignore a specified number of bytes. These actions can be combined
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in any order in the <i>InputData</i> list.</li>
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</ul>
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<h2>Quick Facts</h2>
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<table width="100%" cellpadding="4" cellspacing="0" border="1">
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<tr bgcolor="#CFCFCF">
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<td width="20%" align="center"> </td>
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<td width="80%" align="center">BS2p, BS2pe, and BS2px</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">Receive Rate</td>
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<td>Approximately 20 kBits/sec (low speed, not including reset pulse)</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">Special Notes</td>
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<td>The DQ pin (specified by <i>Pin</i>) must have a 4.7 kΩ pull-up
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resist0r.</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">Related Commands</td>
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<td align="center" colspan="1">
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<p colspan="1" align="center"><a href="OWOUT.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">OWOUT</a>
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</p>
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</td>
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</tr>
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</table>
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<h2>Explanation</h2>
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<p class="PlainText">The 1-Wire protocol is a form of asynchronous serial communication developed by
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Maxim/Dallas Semiconductor. It only requires one I/O pin and that pin can
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be shared between multiple 1-Wire devices. The <span class="keyword_in_text">OWIN</span> command
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allows the BASIC Stamp to receive data from a 1-Wire device.</p>
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<p>The following is an example of the <span class="keyword_in_text">OWIN</span> command:</p><pre class="BScode" xml:space="preserve">
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result VAR Byte
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Main:
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OWIN 0, 1, [result]
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STOP
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</pre>
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<p class="PlainText">This code will transmit a "reset" pulse to a 1-Wire device
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(connected to I/O pin 0) and then will detect the device's "presence" pulse and
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then receive one byte and store it in the variable result. </p>
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<p class="PlainText">The <i>Mode</i> argument is used to control placement of reset pulses (and
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detection of presence pulses) and to designate byte vs. bit input and normal vs.
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high speed<sup>†</sup>. The tables below show the meaning of each of the
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four bits of <i>Mode</i> and some of the 16 possible values and their effect. </p>
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<h3><i>Mode</i> Format bits</h3>
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<table width="35%" cellpadding="4" cellspacing="0" border="1">
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<tr bgcolor="#CFCFCF">
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<td width="50" align="center">Bit</td>
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<td width="200" align="center">Function</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">0</td>
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<td>Front-End Reset<br></br>• 0 = No reset <br></br>• 1 = Generate reset before data</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">1</td>
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<td>Back-End Reset<br></br>• 0 = No reset <br></br>• 1 = Generate reset after data</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">2</td>
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<td>Bit / Byte Transfer<br></br>• 0 = Byte <br></br>• 1 = Bit</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">3</td>
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<td>Low / High Speed<sup>†</sup><br></br>• 0 = Low <br></br>• 1 = High</td>
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</tr>
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</table>
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<p> </p>
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<table width="35%" cellpadding="4" cellspacing="0" border="1">
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<tr bgcolor="#CFCFCF" align="center">
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<td width="50">Mode</td>
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<td>Effect</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">0</td>
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<td>No Reset, Byte mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">1</td>
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<td>Reset before data, Byte mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">2</td>
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<td>Reset after data, Byte mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">3</td>
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<td>Reset before and after data, Byte mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">4</td>
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<td>No Reset, Bit mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">5</td>
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<td>Reset before data, Bit mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">6</td>
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<td>Reset after data, Bit mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">7</td>
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<td>Reset before and after data, Bit mode, Low speed</td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">8</td>
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<td>No Reset, Byte mode, High speed<sup>†</sup></td>
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</tr>
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<tr>
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<td align="center" bgcolor="#CFCFCF">9</td>
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<td>Reset before data, Byte mode, High speed<sup>†</sup></td>
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</tr>
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</table>
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<p><sup>†</sup> The BS2pe is not capable of High-Speed transfers.</p>
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<p> </p>
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<p class="PlainText">The proper value for <i>Mode</i> depends on the 1-Wire device
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and the portion of the communication you're working on. Please consult the data
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sheet for the device in question to determine the correct value for Mode. In many
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cases, however, when using the <span class="keyword_in_text">OWIN</span> command, <i>Mode</i> should be set for
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either No Reset (to receive data from a transaction already started by a <span class="keyword_in_text">OWOUT</span>command) or a Back-End Reset (to terminate the session after data is received).
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This may vary due to device and application requirements, however.</p>
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<p>When using the Bit (rather than Byte) mode of data transfer, all variables in
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the <i>InputData</i> argument will only receive one bit. For example, the following
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code could be used to receive two bits using this mode:</p><pre class="BScode" xml:space="preserve">
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bitOne VAR Bit
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bitTwo VAR Bit
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Main:
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OWIN 0, 6, [bitOne, bitTwo]
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STOP
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</pre>
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<p class="PlainText">In the code above, we chose the value "6" for <i>Mode</i>. This sets Bit transfer
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and Back-End Reset modes. Also, we could have chosen to make the bitOne and bitTwo
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variables each a byte in size, but they still would only have received one bit each
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in the <span class="keyword_in_text">OWIN</span> command (due to the <i>Mode</i> selected).</p>
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<p class="PlainText">The <span class="keyword_in_text">OWIN</span> command's <i>InputData</i> argument is similar to the <b>SERIN</b>command's <i>InputData</i> argument. This means data can be received as ASCII
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character values, decimal, hexadecimal and binary translations and string data as
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in the examples below. (Assume a 1-Wire device is used and that
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it transmits the string, "Value: 3A:101" every time it receives a Front-End Reset
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pulse).</p><pre class="BScode" xml:space="preserve">
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value VAR Byte(13)
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Main:
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OWIN 0, 1, [value] ' receive ASCII code for "V"
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OWIN 0, 1, [DEC value] ' receive the number 3
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OWIN 0, 1, [HEX value] ' receive the number $3A
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OWIN 0, 1, [BIN value] ' receive the number %101
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OWIN 0, 1, [STR value\13] ' receive the string "Value: 3A:101"
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STOP
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</pre>
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<p class="PlainText">The tables below list all the available special formatters and conversion
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formatters available to the <span class="keyword_in_text">OWIN</span> command. See the <a href="SERIN.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">SERIN</a> command for additional information and examples of their use.</p>
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<table width="100%" cellpadding="4" cellspacing="0" border="1">
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<tr bgcolor="#CFCFCF" align="center" valign="top">
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<td width="150">Special Formatter</td>
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<td>Action</td>
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</tr>
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<tr>
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<td align="center">STR ByteArray \L {\E}</td>
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<td>Input a character string of length L into an array. If specified, an end
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character E causes the string input to end before reaching length L.
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Remaining bytes are filled with 0s (zeros).</td>
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</tr>
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<tr>
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<td align="center">WAITSTR ByteArray {\L}</td>
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<td>Wait for a sequence of bytes matching a string stored in an array variable,
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optionally limited to L characters. If the optional L argument is left off,
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the end of the array-string must be marked by a byte containing a zero (0).</td>
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</tr>
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<tr>
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<td align="center">SKIP Length</td>
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<td>Ignore Length bytes of characters.</td>
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</tr>
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<tr>
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<td align="center">SPSTR Length</td>
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<td>Buffer Length bytes (up to 126) of serial characters to Scratchpad RAM,
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starting at location 0. Use <a href="GET.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">GET</a> to retrieve the
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characters.</td>
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</tr>
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</table>
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<p> </p>
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<p>
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<img src="../../graphics/bs2all_inline.gif" border="0" />
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</p>
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<table width="100%" cellpadding="4" cellspacing="0" border="1">
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<tr bgcolor="#CFCFCF" align="center" valign="top">
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<td width="15%">Conversion Formatter</td>
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<td width="45%">Type of Number</td>
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<td width="30%">Numeric Characters Accepted</td>
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<td width="10%">Notes</td>
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</tr>
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<tr align="center">
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<td>DEC{1..5}</td>
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<td>Decimal, optionally limited to 1 - 5 digits</td>
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<td>0 through 9</td>
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<td>1</td>
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</tr>
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<tr align="center">
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<td>SDEC{1..5}</td>
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<td>Signed decimal, optionally limited to 1 - 5 digits</td>
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<td>-, 0 through 9</td>
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<td>1,2</td>
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</tr>
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<tr align="center">
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<td>HEX{1..4}</td>
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<td>Hexadecimal, optionally limited to 1 - 4 digits</td>
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<td>0 through 9, A through F</td>
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<td>1,3</td>
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</tr>
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<tr align="center">
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<td>SHEX{1..4}</td>
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<td>Signed hexadecimal, optionally limited to 1 - 4 digits </td>
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<td>-, 0 through 9, A through F</td>
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<td>1,2,3</td>
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</tr>
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<tr align="center">
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<td>IHEX{1..4}</td>
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<td>Indicated hexadecimal, optionally limited to 1 - 4 digits</td>
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<td>$, 0 through 9, A through F</td>
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<td>1,3,4</td>
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</tr>
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<tr align="center">
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<td>ISHEX{1..4}</td>
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<td>Signed, indicated hexadecimal, optionally limited to 1 - 4 digits</td>
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<td>-, $, 0 through 9, A through F</td>
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<td>1,2,3,4</td>
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</tr>
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<tr align="center">
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<td>BIN{1..16}</td>
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<td>Binary, optionally limited to 1 - 16 digits</td>
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<td>0, 1</td>
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<td>1</td>
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</tr>
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<tr align="center">
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<td>SBIN{1..16}</td>
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<td>Signed binary, optionally limited to 1 - 16 digits</td>
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<td>-, 0, 1</td>
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<td>1,2</td>
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</tr>
|
|||
|
|
<tr align="center">
|
|||
|
|
<td>IBIN{1..16}</td>
|
|||
|
|
<td>Indicated binary, optionally limited to 1 - 16 digits</td>
|
|||
|
|
<td>%, 0, 1</td>
|
|||
|
|
<td>1,4</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr align="center">
|
|||
|
|
<td>ISBIN{1..16}</td>
|
|||
|
|
<td>Signed, indicated binary, optionally limited to 1 - 16 digits</td>
|
|||
|
|
<td>-, %, 0, 1</td>
|
|||
|
|
<td>1,2,4</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr align="center">
|
|||
|
|
<td>NUM</td>
|
|||
|
|
<td>Generic numeric input; hex or binary number must be indicated</td>
|
|||
|
|
<td>$, %, 0 through 9, A through F</td>
|
|||
|
|
<td>1,3,4</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr align="center">
|
|||
|
|
<td>SNUM</td>
|
|||
|
|
<td>Similar to NUM with value treated as signed with range -32768 to +32767</td>
|
|||
|
|
<td>-, $, %, 0 through 9, A through F</td>
|
|||
|
|
<td>1,2,3,4</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
<ol>
|
|||
|
|
<li value="1">All numeric conversions will continue to accept new data until receiving
|
|||
|
|
either the specified number of digits (ex: three digits for DEC3) or a
|
|||
|
|
non-numeric character.</li>
|
|||
|
|
<li value="2">To be recognized as part of a number, the minus sign (-) must immediately
|
|||
|
|
precede a numeric character. The minus sign character occurring in non-numeric
|
|||
|
|
text is ignored and any character (including a space) between a minus and a
|
|||
|
|
number causes the minus to be ignored.</li>
|
|||
|
|
<li value="3">The hexadecimal formatters are not case-sensitive; "a" through "f" means
|
|||
|
|
the same as "A" through "F".</li>
|
|||
|
|
<li value="4">Indicated hexadecimal and binary formatters ignore all characters, even
|
|||
|
|
valid numerics, until they receive the appropriate prefix ($ for hexadecimal,
|
|||
|
|
% for binary). The indicated formatters can differentiate between text and
|
|||
|
|
hexadecimal (ex: ABC would be interpreted by HEX as a number but IHEX would
|
|||
|
|
ignore it unless expressed as $ABC). Likewise, the binary version can
|
|||
|
|
distinguish the decimal number 10 from the binary number %10. A prefix
|
|||
|
|
occurring in non-numeric text is ignored, and any character (including a space)
|
|||
|
|
between a prefix and a number causes the prefix to be ignored. Indicated, signed
|
|||
|
|
formatters require that the minus sign come before the prefix, as in -$1B45.</li>
|
|||
|
|
</ol>
|
|||
|
|
<h3>The 1-Wire Protocol Format</h3>
|
|||
|
|
<p class="PlainText">The 1-Wire protocol has a well-defined standard for transaction
|
|||
|
|
sequences. Every transaction sequence consists of four parts: 1) Initialization, 2)
|
|||
|
|
ROM Function Command, 3) Memory Function Command, and 4) Transaction/Data.
|
|||
|
|
Additionally, the ROM Function Command and Memory Function Command are always 8
|
|||
|
|
bits wide (1 byte in size) and is sent least-significant-bit (LSB) first.</p>
|
|||
|
|
<p>The Initialization part consists of a reset pulse (generated by the master)
|
|||
|
|
and will be followed by a presence pulse (generated by all slave devices). The
|
|||
|
|
figure below details the reset pulse generated by the BASIC Stamp and a typical
|
|||
|
|
presence pulse generated by a 1-Wire slave, in response.</p>
|
|||
|
|
<center>
|
|||
|
|
<img src="../../graphics/ow_pulses.gif" border="0">
|
|||
|
|
</img>
|
|||
|
|
</center>
|
|||
|
|
<p> </p>
|
|||
|
|
<p class="PlainText">This reset pulse is controlled by the lowest two bits of the <i>Mode</i> argument
|
|||
|
|
in the <span class="keyword_in_text">OWIN</span> command. It can be made to appear before the ROM Function
|
|||
|
|
Command (ex: Mode = 1), after the Transaction/Data portion (ex: Mode = 2), before
|
|||
|
|
and after the entire transaction (ex: Mode = 3) or not at all (ex: Mode = 0).
|
|||
|
|
See the section on <i>Mode</i>, above, for more information.</p>
|
|||
|
|
<p class="PlainText">Following the Initialization part is the ROM Function Command. The ROM Function
|
|||
|
|
Command is used to address the desired 1-Wire device. The table
|
|||
|
|
below shows common ROM Function Commands. If only a single 1-Wire
|
|||
|
|
device is connected, the Skip ROM command can be used to address it. If more than
|
|||
|
|
one 1-Wire device is attached, the BASIC Stamp will ultimately have
|
|||
|
|
to address them individually using the Match ROM command.</p>
|
|||
|
|
<table width="100%" cellpadding="4" cellspacing="0" border="1">
|
|||
|
|
<tr bgcolor="#CFCFCF" align="center" valign="top">
|
|||
|
|
<td width="100">Command</td>
|
|||
|
|
<td width="100">Value (HEX)</td>
|
|||
|
|
<td>Action</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td align="center">Read ROM</td>
|
|||
|
|
<td align="center">$33</td>
|
|||
|
|
<td>Reads the 64-bit ID of the 1-Wire device. This command
|
|||
|
|
can only be used if there is a single 1-Wire device on the
|
|||
|
|
line.</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td align="center">Match ROM</td>
|
|||
|
|
<td align="center">$55</td>
|
|||
|
|
<td>This command, followed by a 64-bit ID, allows the BASIC Stamp to address
|
|||
|
|
a specific 1-Wire device.</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td align="center">Skip ROM</td>
|
|||
|
|
<td align="center">$CC</td>
|
|||
|
|
<td>Address a 1-Wire device without its 64-bit ID. This
|
|||
|
|
command can only be used if there is a single 1-Wire device
|
|||
|
|
on the line.</td>
|
|||
|
|
</tr>
|
|||
|
|
<tr>
|
|||
|
|
<td align="center">Search ROM</td>
|
|||
|
|
<td align="center">$F0</td>
|
|||
|
|
<td>Reads the 64-bit IDs of all the 1-Wire devices on the
|
|||
|
|
line. A process of elimination is used to distinguish each unique device.</td>
|
|||
|
|
</tr>
|
|||
|
|
</table>
|
|||
|
|
<p> </p>
|
|||
|
|
<p class="PlainText">The third part, the Memory Function Command, allows the BASIC Stamp to address
|
|||
|
|
specific memory locations, or features, of the 1-Wire device.
|
|||
|
|
Refer to the 1-Wire device's data sheet for a list of the available
|
|||
|
|
Memory Function Commands.</p>
|
|||
|
|
<p class="PlainText">Finally, the Transaction/Data section is used to read or write data to the
|
|||
|
|
1-Wire device. The <span class="keyword_in_text">OWIN</span> command will read data at this
|
|||
|
|
point in the transaction. A read is accomplished by generating a brief low-pulse
|
|||
|
|
and sampling the line within 15 ms of the falling edge of the pulse. This is called
|
|||
|
|
a "Read Slot." The figure below shows typical Read Slots performed by the BASIC
|
|||
|
|
Stamp. See the <a href="OWOUT.htm" target="" title="" alt="" class="MCXref_0" xrefformat="{paratext}">OWOUT</a> command for information on Write Slots.</p>
|
|||
|
|
<center>
|
|||
|
|
<img src="../../graphics/ow_readslots.gif" border="0" />
|
|||
|
|
</center>
|
|||
|
|
<div class="Col2">
|
|||
|
|
<div class="MasterFoot">
|
|||
|
|
<p MadCap:conditions="BSEconditions.BSEWebHelp (Primary)-INCLUDE"><a href="../../HomeTopics/HomePage.htm">Go to Welcome page</a>
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="Col2">
|
|||
|
|
<div class="MasterFoot">
|
|||
|
|
<p style="text-align: right;"><span class="ContactInfoProjectName">BASIC Stamp Help</span> <![CDATA[ ]]><span class="ContactInfoVersion#">Version 2.5.4</span> <![CDATA[ ]]></p>
|
|||
|
|
<p style="text-align: right;">Copyright © <span class="ContactInfoCompanyName">Parallax Inc.</span></p>
|
|||
|
|
<p style="text-align: right;"><span class="SystemShortDate">8/8/2012</span>
|
|||
|
|
</p>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
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