mirror of https://github.com/joan2937/pigpio
84 lines
6.9 KiB
HTML
84 lines
6.9 KiB
HTML
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
|
|
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
|
<head>
|
|
<meta name="description" content="Raspberry Pi Reg. C GPIO library and Python GPIO module and shell command utilities to control the GPIO, including SPI, I2C, and serial links." />
|
|
<meta name="keywords" content="raspberry, pi, C, Python, GPIO, library, shell, command, utilities, module, SPI, I2C, serial" />
|
|
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
|
|
<title>pigpio library</title>
|
|
<link rel="stylesheet" type="text/css" href="scripts/index.css">
|
|
<link rel="icon" href="favicon.ico" type="image/x-icon">
|
|
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
|
|
</head>
|
|
<body>
|
|
|
|
<table style="padding:0px; border:0px; margin:0px; width:780px; background-color:#e0e0e0;">
|
|
<td style="background:#EAF2E6 url('images/sidebar.gif') repeat-y; width:35px; height:100%"></td>
|
|
<td>
|
|
<table>
|
|
<div style="background:url('images/topbar.gif') repeat-x; height: 70px; font-size:1.5em; vertical-align: top;"><a href="index.html"><img src="images/pigpio-logo.gif" border="0" /></a>pigpio library</div>
|
|
</table>
|
|
<table><div>
|
|
<td><img src="images/wheel.jpg" width="250"></td>
|
|
<td><img src="images/srf04.jpg" width="250"></td>
|
|
<td><img src="images/servo.jpg" width="250"></td>
|
|
</div></table>
|
|
<table>
|
|
<td style="vertical-align: top; background-color: #98bf21;"><a class="l1" href="index.html">pigpio</a>
|
|
<a class="l1" href="cif.html">pigpio C I/F</a>
|
|
<a class="l1" href="pigpiod.html">pigpiod</a>
|
|
<a class="l1" href="pdif2.html">pigpiod C I/F</a>
|
|
<a class="l1" href="python.html">Python</a>
|
|
<a class="l1" href="pigs.html">pigs</a>
|
|
<a class="l1" href="piscope.html">piscope</a>
|
|
<a class="l1" href="misc.html">Misc</a>
|
|
<a class="l1" href="examples.html">Examples</a>
|
|
<a class="l1" href="download.html">Download</a>
|
|
<a class="l1" href="faq.html">FAQ</a>
|
|
<a class="l1" href="sitemap.html">Site Map</a>
|
|
</td>
|
|
<td><center><h2>pig2vcd</h2></center>pig2vcd is a utility which reads notifications on stdin and writes the
|
|
output as a Value Change Dump (VCD) file on stdout.
|
|
<br><br>The VCD file can be viewed using GTKWave.
|
|
<h3>Notifications</h3>Notifications consist of 12 bytes with the following binary format.
|
|
<br><br><code>typedef struct<br>{<br> uint16_t seqno;<br> uint16_t flags;<br> uint32_t tick;<br> uint32_t level;<br>} gpioReport_t;<br></code><br><br>seqno: starts at 0 each time the handle is opened and then increments by one for each report.
|
|
<br><br>flags: two flags are defined, PI_NTFY_FLAGS_WDOG and PI_NTFY_FLAGS_ALIVE. If bit 5 is set (PI_NTFY_FLAGS_WDOG) then bits 0-4 of the flags indicate a gpio which has had a watchdog timeout; if bit 6 is set (PI_NTFY_FLAGS_ALIVE) this indicates a keep alive signal on the pipe/socket and is sent once a minute in the absence of other notification activity.
|
|
<br><br>tick: the number of microseconds since system boot. It wraps around after 1h12m.
|
|
<br><br>level: indicates the level of each gpio. If bit 1<<x is set then gpio x is high. pig2vcd takes these notifications and outputs a text format VCD.
|
|
<h3>VCD format</h3>The VCD starts with a header.
|
|
<br><br><code>$date 2013-05-31 18:49:36 $end<br>$version pig2vcd V1 $end<br>$timescale 1 us $end<br>$scope module top $end<br>$var wire 1 A 0 $end<br>$var wire 1 B 1 $end<br>$var wire 1 C 2 $end<br>$var wire 1 D 3 $end<br>$var wire 1 E 4 $end<br>$var wire 1 F 5 $end<br>$var wire 1 G 6 $end<br>$var wire 1 H 7 $end<br>$var wire 1 I 8 $end<br>$var wire 1 J 9 $end<br>$var wire 1 K 10 $end<br>$var wire 1 L 11 $end<br>$var wire 1 M 12 $end<br>$var wire 1 N 13 $end<br>$var wire 1 O 14 $end<br>$var wire 1 P 15 $end<br>$var wire 1 Q 16 $end<br>$var wire 1 R 17 $end<br>$var wire 1 S 18 $end<br>$var wire 1 T 19 $end<br>$var wire 1 U 20 $end<br>$var wire 1 V 21 $end<br>$var wire 1 W 22 $end<br>$var wire 1 X 23 $end<br>$var wire 1 Y 24 $end<br>$var wire 1 Z 25 $end<br>$var wire 1 a 26 $end<br>$var wire 1 b 27 $end<br>$var wire 1 c 28 $end<br>$var wire 1 d 29 $end<br>$var wire 1 e 30 $end<br>$var wire 1 f 31 $end<br>$upscope $end<br>$enddefinitions $end<br></code><br><br>The header defines gpio identifiers and their name. Each gpio identifier
|
|
must be unique. pig2vcd arbitrarily uses 'A' through 'Z' for gpios 0
|
|
through 25, and 'a' through 'f' for gpios 26 through 31.
|
|
The corresponding names are 0 through 31.<br>
|
|
<br><br>The VCD file may be edited to give a frendlier name, e.g. 8 could be
|
|
changed to ENCODER_A if an encoder switch A is connected to gpio 8.
|
|
<br><br>Following the header pig2vcd takes notifications and outputs a timestamp
|
|
followed by a list of one or more gpios which have changed state.
|
|
The timestamp consists of a '#' followed by the microsecond tick.
|
|
The state lines contain the new state followed by the gpio identifier.
|
|
<br><br><code>#1058747<br>0H<br>0I<br>#1059012<br>1H<br>#1079777<br>1I<br>#1079782<br>0I<br>#1079852<br>1I<br>#1079857<br>0I<br>0H<br>#1165113<br>1H<br>#1165118<br>0H<br>#1165153<br>1H<br></code></td>
|
|
</table>
|
|
<div style="vertical-align: center; text-align: center; background-color:#98bf21; font-size:0.8em; height:30px"><a class="l2" href="index.html">[pigpio]</a>
|
|
<a class="l2" href="cif.html">[pigpio C I/F]</a>
|
|
<a class="l2" href="pigpiod.html">[pigpiod]</a>
|
|
<a class="l2" href="pdif2.html">[pigpiod C I/F]</a>
|
|
<a class="l2" href="python.html">[Python]</a>
|
|
<a class="l2" href="pigs.html">[pigs]</a>
|
|
<a class="l2" href="piscope.html">[piscope]</a>
|
|
<a class="l2" href="misc.html">[Misc]</a>
|
|
<a class="l2" href="examples.html">[Examples]</a>
|
|
<a class="l2" href="download.html">[Download]</a>
|
|
<a class="l2" href="faq.html">[FAQ]</a>
|
|
<a class="l2" href="sitemap.html">[Site Map]</a>
|
|
</div>
|
|
<table><tr>
|
|
<td style="width: 200px"><div style="text-align: left;"><small>© 2012-2020</small></div></td>
|
|
<td style="width: 350px"><div style="text-align: center;">e-mail: pigpio @ abyz.me.uk</div></td>
|
|
<td style="width: 200px"><div style="text-align: right;"><small>Updated: 29/04/2020</small></div></td>
|
|
</tr></table>
|
|
</td>
|
|
</table>
|
|
</body>
|
|
</html>
|