92 lines
3.2 KiB
HTML
92 lines
3.2 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
|
<HTML>
|
|
<HEAD>
|
|
<META NAME="GENERATOR" CONTENT="SGML-Tools 1.0.9">
|
|
<TITLE>Coffee Making: Software</TITLE>
|
|
<LINK HREF="Coffee-5.html" REL=next>
|
|
<LINK HREF="Coffee-3.html" REL=previous>
|
|
<LINK HREF="Coffee.html#toc4" REL=contents>
|
|
</HEAD>
|
|
<BODY>
|
|
<A HREF="Coffee-5.html">Next</A>
|
|
<A HREF="Coffee-3.html">Previous</A>
|
|
<A HREF="Coffee.html#toc4">Contents</A>
|
|
<HR>
|
|
<H2><A NAME="s4">4. Software</A></H2>
|
|
|
|
<P>
|
|
<P>
|
|
<H2><A NAME="ss4.1">4.1 Programming</A>
|
|
</H2>
|
|
|
|
<P>You will have to build an executable that will take the following steps:
|
|
<UL>
|
|
<LI>Get permission to use I/O address space, by calling kernel, with
|
|
the call <B>ioperm</B>: eg <EM>ioperm( BASE, range ,1); </EM></LI>
|
|
<LI>Perform an out request instruction, to set the 0-5V voltage to the
|
|
parallel port, eg <EM>outb( 1, BASE );</EM></LI>
|
|
<LI>Wait enough time so the coffee is made. It would be nice
|
|
if that time is read by looking at the command line.</LI>
|
|
<LI>Then it will turn off the coffee-machine: outb( 0 , BASE );</LI>
|
|
<LI>Before ending it should give back the parallel port
|
|
with an <EM>ioperm( BASE, range, 0);</EM></LI>
|
|
</UL>
|
|
|
|
Change BASE = 0x3bc for /dev/lp0, 0x378 for /dev/lp1, and 0x278
|
|
for /dev/lp2; range=8.
|
|
<P>
|
|
<P>It would be useful if you had that program setuid,
|
|
so that everybody can drink coffee! You BOFH!
|
|
<P>
|
|
<H2><A NAME="ss4.2">4.2 Device driver</A>
|
|
</H2>
|
|
|
|
<P>
|
|
<P>Just read
|
|
<A HREF="http://en.tldp.org/LDP/khg/HyperNews/get/khg.html">kernel hacker's guide</A>,
|
|
to implement a device driver; you might also do it in user space.
|
|
Please compile it as a module, so that we won't need a
|
|
kernel compile in every update.
|
|
Then write:
|
|
<P>
|
|
<PRE>
|
|
echo cappuccino >/dev/coffee
|
|
</PRE>
|
|
<P>And you will have a hot cup of coffee in minutes!
|
|
Remember to give the right permissions to /dev/coffee,
|
|
depending on whether you want only root making coffee or not.
|
|
<P>
|
|
<P>The advantage of this method is that it supports feedback
|
|
from the coffee-machine by using the ACK of parallel port and such,
|
|
so that smart coffee-machines can produce an interrupt when ready.
|
|
<P>
|
|
<P>Do it yourself, after reading the excellent book
|
|
of Alessandro Rubini and Jonathan Corbet
|
|
<A HREF="http://www.xml.com/ldd/chapter/book/index.html">Linux Device Drivers</A>
|
|
and studying the
|
|
<A HREF="http://lxr.linux.no/source/">Cross Reference Linux</A> source code repository.
|
|
<P>
|
|
<P>
|
|
<H2><A NAME="ss4.3">4.3 Connecting with the Internet</A>
|
|
</H2>
|
|
|
|
<P>If you have implemented the controlling program in C (see above),
|
|
you just have to write a CGI script to turn ON and OFF
|
|
the coffee-machine or pass along more complex instructions.
|
|
You should write some nice webpages, explaining how to make coffee,
|
|
and put them on an <B>apache</B> web server...
|
|
<P>
|
|
<P>...LAMP technology (Linux, Apache, MySQL, [Perl|Python|PHP]),
|
|
will help you to build a perfect user-customizable coffee system!
|
|
<P>At some time in the future when the applications get rather complex,
|
|
you might want to extend on the basis of Flow-Based Programming:
|
|
<A HREF="http://www.jpaulmorrison.com/fbp/">http://www.jpaulmorrison.com/fbp/</A>.
|
|
What a great match for a great Coffee Machine!
|
|
<P>
|
|
<HR>
|
|
<A HREF="Coffee-5.html">Next</A>
|
|
<A HREF="Coffee-3.html">Previous</A>
|
|
<A HREF="Coffee.html#toc4">Contents</A>
|
|
</BODY>
|
|
</HTML>
|