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diff --git a/static/freebsd/man4/ow_temp.4 3.html b/static/freebsd/man4/ow_temp.4 3.html new file mode 100644 index 00000000..2c32b344 --- /dev/null +++ b/static/freebsd/man4/ow_temp.4 3.html @@ -0,0 +1,140 @@ +<table class="head"> + <tr> + <td class="head-ltitle">OW_TEMP(4)</td> + <td class="head-vol">Device Drivers Manual</td> + <td class="head-rtitle">OW_TEMP(4)</td> + </tr> +</table> +<div class="manual-text"> +<section class="Sh"> +<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> +<p class="Pp"><code class="Nm">ow_temp</code> — <span class="Nd">Dallas + Semiconductor 1-Wire Temperature sensor</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> +<p class="Pp"><code class="Cd">device ow_temp</code></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp">The <code class="Nm">ow_temp</code> module supports many of the + 1-Wire temperature sensors.</p> +<p class="Pp">The sensor is read periodically and the results returned via a + <a class="Xr">sysctl(3)</a> as described below.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HARDWARE"><a class="permalink" href="#HARDWARE">HARDWARE</a></h1> +<p class="Pp">The <code class="Nm">ow_temp</code> driver supports the following + temperature sensors:</p> +<p class="Pp"></p> +<table class="Bl-column Bl-compact"> + <tr> + <td>DS1820</td> + <td>1-Wire Digital Thermometer</td> + </tr> + <tr> + <td>DS18S20</td> + <td>High-Precision 1-Wire Digital Thermometer</td> + </tr> + <tr> + <td>DS18B20</td> + <td>Programmable Resolution 1-Wire Digital Thermometer</td> + </tr> + <tr> + <td>DS1822</td> + <td>Econo 1-Wire Digital Thermometer</td> + </tr> + <tr> + <td>DS1825</td> + <td>Programmable Resolution 1-Wire Digital Thermometer with 4-bit ID</td> + </tr> + <tr> + <td>MAX31820</td> + <td>1-Wire, Parasite-Power, Ambient Temperature Sensor</td> + </tr> +</table> +<p class="Pp">The driver supports Family codes 0x10, 0x22, 0x28, and 0x3b.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYSCTL"><a class="permalink" href="#SYSCTL">SYSCTL</a></h1> +<p class="Pp">The <code class="Nm">ow_temp</code> driver reports data via + <a class="Xr">sysctl(8)</a> entries in the device's node in the + <a class="Xr">sysctl(8)</a> tree:</p> +<dl class="Bl-tag"> + <dt>temperature</dt> + <dd>The last temperature read, in milli-Kelvin.</dd> + <dt>badcrc</dt> + <dd>The number of CRC errors in reading the temperature from the device. Some + CRC errors are to be expected. High rates of CRC errors, however, + generally indicate a noisy environment, cabling issues, or too many + devices on the bus.</dd> + <dt>badread</dt> + <dd>The number of times a non-CRC error was encountered reading the + temperature from the card. This type of error is very rare.</dd> + <dt>reading_interval</dt> + <dd>The time, in ticks, between successive reads of the sensor.</dd> + <dt>parasite</dt> + <dd>This item is non-zero when the device is connected using its parasitic + power mode. It can also indicate a wiring error.</dd> +</dl> +<p class="Pp">Temperatures are reported in milli-Kelvin, even though the + absolute accuracy is around 0.2 degrees for the good devices and around 1 + degree for cheaper devices. The devices report in steps of 0.0625 degrees. + The driver preserves the precision of the device's measurements in its + <a class="Xr">sysctl(8)</a> reports. These devices often have a much higher + relative accuracy and repeatability than their absolute accuracy. This makes + them well suited for control loops that strive for stability and become + possible if the full precision is preserved.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE + ALSO</a></h1> +<p class="Pp"><a class="Xr">ow(4)</a>, <a class="Xr">owc(4)</a>, + <a class="Xr">sysctl(8)</a>, <a class="Xr">owll(9)</a>, + <a class="Xr">own(9)</a></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="LEGAL"><a class="permalink" href="#LEGAL">LEGAL</a></h1> +<p class="Pp">1-Wire is a registered trademark of Maxim Integrated Products, + Inc.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="HISTORY"><a class="permalink" href="#HISTORY">HISTORY</a></h1> +<p class="Pp">The <code class="Nm">ow_temp</code> driver first appeared in + <span class="Ux">FreeBSD 11.0</span>.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="AUTHORS"><a class="permalink" href="#AUTHORS">AUTHORS</a></h1> +<p class="Pp">The <code class="Nm">ow_temp</code> device driver and this manual + page were written by <span class="An">Warner Losh</span>.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="BUGS"><a class="permalink" href="#BUGS">BUGS</a></h1> +<p class="Pp">The parasitic mode of the devices does not work. It requires + support from the <a class="Xr">owc(4)</a> driver that is unimplemented.</p> +<p class="Pp" id="DS1825">The ID bits from the + <a class="permalink" href="#DS1825"><i class="Em">DS1825</i></a> are not + recognized or reported.</p> +<p class="Pp">The type of the device is not reported via + <a class="Xr">sysctl(8)</a>.</p> +<p class="Pp">Alarm mode is not supported. It is not possible to set the low and + high alarm temperatures.</p> +<p class="Pp">There is no way to write to the EEPROM.</p> +<p class="Pp">“Convert Temperature” requests are sent directly to + the device. There is no way to use the broadcast ability of the 1-Wire bus + to do all the conversions in parallel.</p> +<p class="Pp">It is not possible to set the precision on those devices that + support it.</p> +<p class="Pp">The time to convert is fixed at 1 second, even though some devices + are faster.</p> +<p class="Pp">There is no character device to supply a stream of readings to a + program. Programs interested in the temperature must poll the sysctl to get + the temperature.</p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">November 22, 2024</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |