[i2c] newbie: connection problem with parallel port

pierre demanax baddemanax at hotmail.com
Mon Nov 6 16:39:34 CET 2006

Hi all,

I would like to connect my pc running damn small linux ( kernel 2.4.26) via 
the parallel port to a i2c chip PCF8584.

I used a philips like adapters on the parallel port ( using the following 
pining : pin 17 for the SCL output, pin 15 for the SCL input, pin 9 for the 
SDA out , pin 11for the SDA in ...)

I did the following modprobe :

modprobe i2c-core
modprobe i2c-dev
modprobe i2c-parport
modprobe i2c-philips-par
modprobe i2c-algo-bit

What i got from this are two files in /proc/bus.

the first one is i2c which contains : i2c-0    i2c   Philips parallel port 
adapter    bit-shift algorithm
the other one i2c-0 is empty

when i look in the dev folder, nothing is present: ls /dev/i2c* is empty

Then i cannot used any C application to communicate with the the PCF8584 as 
it expects any files in the /dev/i2c*

As i am a newbie in this field maybe i did something wrong.

Are the pining i am using compatible with the driver ( driver version i see 
with dmesg is 2.6.1 from 30/08/2001)
is there any problem possible with the default clock speed of the PC ( i 
know that chip is rather old and cannot work at the actual i2c speed)
The chip address is 0x40 for reading and 0x41 fro writing)

Thanks in advance, i hope somebody will be able to help me out.


Zoé a trouvé le truc pour travailler en groupe sans crêpage de chignon. 

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