pylcd.docbook

linux下LCD驱动的例子代码

<sect1 id="pyramid-howto">
<title>The pyramid Driver</title>

<para>
This section talks about using LCDproc with programmable LC displays
sold by <ulink url="http://www.pyramid.de/">Pyramid Ccomputer</ulink>.
</para>

<para>
Pyramid Computer builds these LC displays into its thriving server products
to show system data, and to allow the user to change important parameters or
shut down the appliance in a controlled manner.
The LCD module, accessible via USB, can be integrated by Pyramid's BTO server
and appliance manufacturing division at the customer's request or it can be
made available separately for self-integration, e.g. as a 5.25" module. 
</para>

<sect2 id="pyramid-features">
<title>Features</title>

<para>
The displays are 16 characters wide and 2 lines high. They have 4 programmable
buttons as well as 3 (or 9) LEDs which can also be software controlled.
</para>

</sect2>


<sect2 id="pyramid-requirements">
<title>Requirements</title>

<para>
For Linux the driver depends on features of the <filename>ftdi_sio.ko</filename>
that have only been added to quite recent version of the 2.6 kernel series.
For older Linux kernels of the 2.6 series (or even the 2.4 series) that patch
to <filename>ftdi_sio.c</filename> might help: 
<ulink url="http://www.pyramid.de/d/downloads/patch-4-linux-2.6.13-14.txt">
http://www.pyramid.de/d/downloads/patch-4-linux-2.6.13-14.txt</ulink>.
</para>

</sect2>


<sect2 id="pyramid-ledoutput">
<title>LED output</title>

<para>
I've added support for the LEDs on the Pyramid LC-Display to the
"pyramid" driver of lcdproc. 
</para>

<para>
Since it seems that LEDs on an LCD are not directly supported by the
lcdproc API I've used the "output" command of the server to trigger the
LEDs, similar to what the IOWarrior driver does.
</para>

<para>
The Pyramid LC-Display exists in two different versions, with 3 and with
9 LEDs. 2 of these LEDs can not be controlled by software but are
usually hard wired to power and HDD. The other 1 or 7 LEDs can now be
controlled by sending an "output" command to the server. The one
argument to the output command is a bitmask that controls the LEDs.
</para>

<screen>
bit 0: LED3
bit 1: LED4
bit 2: LED5
bit 3: LED6
bit 4: LED7
bit 5: LED8
bit 6: LED9
</screen>

<para>
There's no way of finding out whether 3 or 9 LEDs are available, so it
is up to the software to do the right thing.
</para>

<example>
<title>How to use the LED output from the client</title>
<programlisting>
telnet localhost 13666
hello
output 67
</programlisting>

will light up LEDs 3, 4 and 9.

<programlisting>
output 0
</programlisting>

will clear all LEDs.
</example>

<para>
More information on the Pyramid LC-Display can be found here:
<ulink url="http://www.pyramid.de/e/produkte/server/pyramid-lcd.php"></ulink>
</para>

</sect2>

Author
<author>
  <firstname>Stefan</firstname>
  <surname>Reinauer</surname>
</author>

coresystems GmbH · Brahmsstr. 16 · D-79104 Freiburg i. Br.
Tel.: [phone] · Fax: [phone]
Email: [e-mail]  · http://www.coresystems.de/

<!-- ## Pyramid LCD driver ## -->
<sect2 id="pyramid-config">
<title>Configuration in LCDd.conf</title>

<sect3 id="pyramid-config-section">
<title>[pyramid]</title>

<variablelist>
<varlistentry>
  <term>
    <command>Device=</command>
    <arg choice="plain"><replaceable>DEVICE</replaceable></arg>
  </term>
  <listitem><para>
  Device to connect to. Default: <filename>/dev/lcd</filename>
  </para></listitem>
</varlistentry>
</variablelist>

</sect3>

</sect2>

</sect1>