Popular coffee among programmers because doesn't need a lot of care; like commercial software. Its exciting taste has inspired thousands of programmers in writing incredible software, written in the very first ours of a day. Windows for example was written at 5:00 o'clock in the morning, Due to coffee! A result is guaranteed.

Nescafe is a rather strong coffee, made by pouring hot water in a mixture of coffee, sugar and some water. You usually take 1 spoon of coffee and 1 spoon of sugar with just a bit of water, to mix it. In the meantime you should have the water boiling. As soon as the water is hot enough, you mix them all together and preferably add milk. Although you can use something simpler than a coffee-machine to boil the water, I have seen this done many times...

A popular variation of the above mentioned coffee. Actually, it doesn't need a coffee-machine, rather a refrigerator for cold water and ice-cubes.

This is a difficult one, read coffee-faq (see 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.

(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: ent= in DB25 Cent Name of Reg =ent out pin pin Signal Bit Function Notes ------ ---- ---- -------- --- ----------------------------- =ent 1 1 -Strobe C0- Set Low pulse ent0.5 us to send =ent 2 2 Data 0 D0 Set to least significant data =ent 3 3 Data 1 D1 ... =ent 4 4 Data 2 D2 ... =ent 5 5 Data 3 D3 ... =ent 6 6 Data 4 D4 ... =ent 7 7 Data 5 D5 ... =ent 8 8 Data 6 D6 ... =ent 9 9 Data 7 D7 Set to most significant data ent= 10 10 -Ack S6+ IRQ Low Pulse ~ 5 uS, after accept ent= 11 11 +Busy S7- High for Busy/Offline/Error ent= 12 12 +PaperEnd S5+ High for out of paper ent= 13 13 +SelectIn S4+ High for printer selected =ent 14 14 -AutoFd C1- Set Low to autofeed one line ent= 15 32 -Error S3+ Low for Error/Offline/PaperEnd =ent 16 31 -Init C2+ Set Low pulse ent 50uS to init =ent 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 ent-\/\/\/\/---| NPN Transistor: BC547A or 2N2222A data pi |\ E | V | parallel port ent--------------+ ground pin | Ground Connect Vcc with the same voltage as the relay type (usually 5 or 12V). Obviously, the relay's specifications should be scaled for your coffee-machine.

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 MOC301ent012], 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 +---/\/\/\----+-----+ +----/\/\/-+--/\/\/\---+-------ent 120V | 1| |6 | | Hot | +=====+ | | MT1 | | MC | TRIAC | +-+ | | 3032| Driver | G | | TRIAC | +=====+ | /| | \ 2| |4 | / +-+ 2N3904 |----+ | | | | MT2 / | +--------- | -------+ | V \ | | | | / | \ | | \ 43 .01u --- 10k / | | / 500V --- \ | | | | / | +------+ | | | Neutral | +--------+--+---o o--ent 120V / load ent-/\/\--| 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: Get permission to use I/O address space, by calling kernel, with the command ioperm: eg ioperm( BASE, range ,1); Perform an out request instruction, to set the 0-5V voltage to the parallel port, eg outb( 1, BASE );Wait enough time so the coffee is made. It would be nice if that time is read by looking at the command line.Then it will turn off the coffee-machine: outb( 0 , BASE );Before ending it should give back the parallel port with a ioperm( BASE, range, 0); 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 , 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 ent/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 . Remember, that magaz is greek it will look like that to you.

My name is 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.

Ethiopia: Identified as the originating country of coffee. As many people corrected, coffee did not originally come from America nor was brought by Christofer Colombus. It was popular in the Middle East long before America was discovered. Still, we can remember , as the person who brought tobacco and chocolate in Europe. Kostas Lialiambis is the one who dared saying that he can't make coffee with his Linux box. Panagiotis Vrionis, Yannakopoulos Haralambos, for giving me interesting and humorous notes. NUMEROUS people on the internet with additions and remarks.