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diff --git a/static/freebsd/man4/htu21.4 3.html b/static/freebsd/man4/htu21.4 3.html new file mode 100644 index 00000000..71ac5903 --- /dev/null +++ b/static/freebsd/man4/htu21.4 3.html @@ -0,0 +1,106 @@ +<table class="head"> + <tr> + <td class="head-ltitle">HTU21(4)</td> + <td class="head-vol">Device Drivers Manual</td> + <td class="head-rtitle">HTU21(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">htu21</code> — <span class="Nd">driver for + HTU21D and compatible temperature and humidity sensors</span></p> +</section> +<section class="Sh"> +<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> +<p class="Pp">To compile this driver into the kernel, place the following lines + in your kernel configuration file:</p> +<div class="Bd Pp Bd-indent"><code class="Cd">device htu21</code> +<br/> +<code class="Cd">device iicbus</code></div> +<p class="Pp">Alternatively, to load the driver as a module at boot time, place + the following line in <a class="Xr">loader.conf(5)</a>:</p> +<div class="Bd Pp Bd-indent Li"> +<pre>htu21_load="YES"</pre> +</div> +</section> +<section class="Sh"> +<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> +<p class="Pp">The <code class="Nm">htu21</code> driver provides temperature and + relative humidity readings over I2C bus for the supported sensors:</p> +<ul class="Bl-bullet Bl-compact"> + <li>HTU21D</li> + <li>SHT21</li> + <li>Si7021</li> +</ul> +<p class="Pp">The <code class="Nm">htu21</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 temperature, in hundredths of Kelvin.</dd> + <dt>humidity</dt> + <dd>The relative humidity, in hundredths of a percent.</dd> + <dt>crc_errors</dt> + <dd>The number of CRC errors in reading the measurements from the device.</dd> + <dt>power</dt> + <dd>The good power indication. This can be useful with battery powered + sensors.</dd> + <dt>heater</dt> + <dd>The built-in heater control. The heater can be used for testing and for + recovery from saturation after high humidity.</dd> + <dt>hold_bus</dt> + <dd>Whether the sensor should hold SCL low while performing the measurement. + Normally, the sensor releases the bus and NACKs all accessed until the + measurement is completed. The hold mode may be useful in mult-master + environments.</dd> +</dl> +<p class="Pp">On an <a class="Xr">FDT(4)</a> based system the following + properties must be set:</p> +<dl class="Bl-tag"> + <dt id="compatible"><var class="Va">compatible</var></dt> + <dd>Must be set to "meas,htu21".</dd> + <dt id="reg"><var class="Va">reg</var></dt> + <dd>The I2C address of <code class="Nm">htu21</code>. Although, it is + hard-wired to 0x40 (7-bit) on all supported sensors.</dd> +</dl> +<p class="Pp">The DTS part for a <code class="Nm">htu21</code> device usually + looks like:</p> +<div class="Bd Pp Li"> +<pre>/ { + + ... + htu21d { + compatible = "meas,htu21"; + reg = <0x40>; + }; +};</pre> +</div> +</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">fdt(4)</a>, <a class="Xr">iicbus(4)</a>, + <a class="Xr">sysctl(8)</a></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">htu21</code> driver and this manual page was + written by <span class="An">Andriy Gapon</span> + <<a class="Mt" href="mailto:avg@FreeBSD.org">avg@FreeBSD.org</a>>.</p> +</section> +<section class="Sh"> +<h1 class="Sh" id="BUGS"><a class="permalink" href="#BUGS">BUGS</a></h1> +<p class="Pp">There is no way to control the measurement resolution.</p> +<p class="Pp">Some sensor variants do not provide a serial number or use an + incompatible format. The <code class="Nm">htu21</code> driver does not + distinguish those variants and may complain about incorrect serial number + checksum.</p> +</section> +</div> +<table class="foot"> + <tr> + <td class="foot-date">January 19, 2021</td> + <td class="foot-os">FreeBSD 15.0</td> + </tr> +</table> |