Guide pratique de la cafetière sous Linux

Ce café le plus populaire parmi les programmeurs car il nécesite peu d'attention; comme les logiciels propriétaires. Son goût très excitant a inspiré des milliers de programmeurs lors de l'écriture des logiciels les plus surprenants, écrits dans les premières heures du jour. Windows, par exemple, a été écrit à 5h00. Grâce au café, le résultat est garanti.

Le Nescafé est assez fort, obtenu en versant de l'eau chaude sur un mélange de café, sucre et eau. Habituellement vous prenez 1 cuillère de café, 1 de sucre et mélanger avec un peu d'eau. Dans le même temps, mettez de l'eau à bouillir. Dès que l'eau est suffisamment chaude, vous mélangez le tout et ajoutez du lait selon votre goût.

Une variante populaire des cafés déjà mentionnés. En rélaité il ne nécessite pas de cafetière, mais d'un réfrigérateur pour l'eau froide et les glaçons.

Le Freddo est difficile à préparer, consultez la coffee-faq notée dans les references.

Espresso is a very strong, italian sort of coffee. You serve it in small cups (You ask why? See chapter: Overdose Symptomes) with on or to pieces of lump sugar. To produce a good espresso you need fresh grinded coffee beans, water, lump sugar and a special machine. These machines boil the water and press the very hot steam through the grinded coffee beans. You can buy a super-duper-automatic machine for a lot of money. But a low cost machine is useable, too.

OK, lets start. Fill water in your machine. Let it become hot. In the meantime fill about 1 teespoon of coffeepowder in the filterhandle of your machine. Press the coffeepowder down. Not too much. Now the water is at the right temperature. Attach the filterhandle to the machine and let the machine work. After about 30 seconds you can serve a delicate, hot espresso. It is fine after a good meal. You feel good and can code for a few more hours.

L'expresso est très fort, ressemblant au café italien. Il est servi dans une petite tasse (Vous demandez pourquoi ? Lisez le paragraphe : Symptômes d'overdose) avec un ou deux sucre en morceaux. Pour obtenir un bon expresso, vous avez besoin de café fraichement moulu. du sucre en morceaux et une machine spéciale. Ces machines produise de la vapeur qui ensuite traverse le café moulu. Vous pouvez acheter une super-duper-automatic machine

(See also chapter: Espresso) If you have a more profi-like machine, you can use it, to froth milk with it. You need this feature to make a creamy sort of coffee. It is easy to prepare. Put some frothed milk in a coffee pot and fill it up with espresso. Then decorade with some chokolade flakes. That's it.

Here is a simple example to get a voltage 0-5V from the parallel port of the computer.

      Back View          -----    Pin 10 - ACK
      Male DB-25         |   |    Pin  9 - D7
      Connector          |   |                           Pin 2 - D0
                         v   v                           v   Pin 1 -
~Strobe
       ____________________________________________________________
      /                                                            \
      \     13  12  11  10   9   8   7   6   5   4   3   2   1     /
       \                                                          /
        \     25  24  23  22  21  20  19  18  17  16  15  14     /
         \______________________________________________________/

Pin 1 is Strobe (inverse logic)

Pins 2-9 is DATA BUS's signals, exactly what was written to the parallel port's latches with an OUTB command.

Pin 10 is the acknowledge signal (ACK), controlled by you, so that you can produce an interrupt to the CPU.

Pins 18-25 are short-circuited and this is the ground (GND).

In detail:

<= in   DB25    Cent    Name of         Reg
=> out  pin     pin     Signal          Bit     Function Notes
------  ----    ----    --------        ---     -----------------------------
=>       1       1      -Strobe         C0-     Set Low pulse >0.5 us to send
=>       2       2      Data 0          D0      Set to least significant data
=>       3       3      Data 1          D1      ...
=>       4       4      Data 2          D2      ...
=>       5       5      Data 3          D3      ...
=>       6       6      Data 4          D4      ...
=>       7       7      Data 5          D5      ...
=>       8       8      Data 6          D6      ...
=>       9       9      Data 7          D7      Set to most significant data
<=      10      10      -Ack            S6+ IRQ Low Pulse ~ 5 uS, after accept
<=      11      11      +Busy           S7-     High for Busy/Offline/Error
<=      12      12      +PaperEnd       S5+     High for out of paper
<=      13      13      +SelectIn       S4+     High for printer selected
=>      14      14      -AutoFd         C1-     Set Low to autofeed one line
<=      15      32      -Error          S3+     Low for Error/Offline/PaperEnd
=>      16      31      -Init           C2+     Set Low pulse > 50uS to init
=>      17      36      -Select         C3-     Set Low to select printer
==      18-25   19-30,  Ground

The simplest circuit that one can build is:

                             Vcc
                              |
                              +------+
                              |    __|__
                            Relay   /^\  Diode 1N4002
                             Coil  /---\
                              |      |
                              +------+
                              |
                           | / 
                 4.7K    B |/  C
parallel port >-\/\/\/\/---|        NPN Transistor: BC547A or 2N2222A
data pi                    |\  E
                           | V
                             |
parallel port >--------------+
ground pin                   |
                          Ground

Barmen, tend to put the relay AFTER the transistor, at the emitter (E) pin instead of the collector (C) pin. This is bad practice because it biases the transistor badly, and may result in bad coffee :-). Diode 1N4002 is useful to protect the transistor from the relay's currents. If you don't use it the transistor will become dark and smelly...

If you only want a simple circuit, you can use Motorola's triac driver MOC301[012], together with a general purpose TRIAC like SC141D. This method has the advantage that you don't need an extra power supply.

For non-inductive loads, this is the circuitry:

        270     1 +-------+ 6    180
  +5v -VAVAVA-----+       +----VAVAVA-----+-------------- Line Hot
                2 |  MOC  |               |
  TTL in ---------+ 3012  +nc            VA  SC141D
                  |       | 4           / |
                nc+       +------------/  |
                  +-------+               +----\/\/\/---- Line Neutral
                                                LOAD

If you are going to work with 220V, try to obtain a 3021. Inductive loads should be used in conjuction with bypass capacitors, see Motorola Application Note AN-780. Coffee-machines are mainly resistive loads and not inductive (like a motor), but who knows what yours is!

+5VDC
|    180                      180            2.2k
+---/\/\/\----+-----+   +----/\/\/-+--/\/\/\---+-------> 120V
              |    1|   |6         |           |         Hot
              |    +=====+         |           | MT1
              |    | MC  | TRIAC   |          +-+
              |    | 3032| Driver  |        G | | TRIAC
              |    +=====+         |         /| |
              \    2|   |4         |        / +-+
       2N3904  |----+   |          |        |  | MT2
              /     |   +--------- | -------+  |
             V      \              |        |  |
             |      /              |        \  |
             |      \ 43    .01u  ---   10k /  |
             |      /       500V  ---       \  |
             |      |              |        /  |
             +------+              |        |  |            Neutral
             |                     +--------+--+---o    o--> 120V
             /                                      load
 >-/\/\--|  2N3904
             \
              V
              |
             ---
            ///
You should change resistors accordingly for 220V.

Circuit description:

The MC3032 is an optoisolator TRIAC driver. The 180-ohm resistor sets the current for the LED emitter in the optoisolator. Change the value of this resistor - if necessary - to get a reasonable current (e.g., 15 mA).

Note that you cannot test this circuit without a load. The TRIAC will not switch unless connected to an AC voltage source, so you can't test it for simple switching without applying AC and a load. Note the 500V rating on the .01 cap.

You will have to build an executable that will work like this:

Change BASE = 0x3bc for /dev/lp0, 0x378 for /dev/lp1, and 0x278 for /dev/lp2, range=8.

It would be useful if you had that program setuid, so that everybody can drink coffee!

Just read kernel hacker's guide, implement a device driver (it could even be user space I think). Please compile it as a module, so that we won't need a kernel compile in every update. Then write:

echo cappuccino >/dev/coffee

And you will have a hot cup of coffee in minutes! Remember to give the right permission to /dev/coffee, depending on whether you want only root making coffee or not.

The advantage of this method is that it supports feedback from the coffee-machine by using the ACK of parallel port, so that smart coffee-machines could produce an interrupt.

Do it as homework.

If you have implemented the C program (see above), you just have to write a simple CGI script to turn ON and OFF the coffee-machine. You should write some nice webpages, explaining how to make coffee, and put them on an apache web server...

This document was initially written as part of a small debate in the linux-greek-users list , whether linux can make coffee or not. It has been an article in our beautiful online magazine about Linux called magaz. Remember, that magaz is greek it will look like that to you.

My name is Fotis Georgatos and I have also been in the past busy with the greek documentation and wwwpages maintainance. I welcome submissions to this HOWTO, as long as you're not anxious about the changes.

I'm Annie Pinder and a coffee fan. I live in England. I made the language changes on this document. I'm currently in the English equivalent of High School, in my final compulsory year.

The casual copyright with everything you get with linux... To find it, you'll have to read all of HOWTOs and average out the most common. Otherwise, no, you cannot copy it.