5 2004-07-06, Jean Delvare
7 This is a unified driver for several i2c-over-parallel-port adapters,
8 such as the ones made by Philips, Velleman or ELV. This driver is
9 meant as a replacement for the older, individual drivers:
13 * video/i2c-parport (NOT the same as this one, dedicated to home brew
16 It currently supports the following devices:
18 * home brew teletext adapter
19 * Velleman K8000 adapter
21 * Analog Devices evaluation boards (ADM1025, ADM1030, ADM1031, ADM1032)
23 These devices use different pinout configurations, so you have to tell
24 the driver what you have, using the type module parameter. There is no
25 way to autodetect the devices. Support for different pinout configurations
26 can be easily added when needed.
29 Building your own adapter
30 -------------------------
32 If you want to build you own i2c-over-parallel-port adapter, here is
33 a sample electronics schema (credits go to Sylvain Munaut):
36 Side ___________________Vdd (+) Side
45 SCL ----------x--------o |-----------x------------------- pin 2
49 SDA ----------x----x---| o---x--------------------------- pin 13
53 ---------o |----------------x-------------- pin 3
66 - This is the exact pinout and electronics used on the Analog Devices
69 - All inverters -o |- must be 74HC05, they must be open collector output.
71 - All resitors are 10k.
72 - Pins 18-25 of the parallel port connected to GND.
73 - Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high.
74 The ADM1032 evaluation board uses D4-D7. Beware that the amount of
75 current you can draw from the parallel port is limited. Also note that
76 all connected lines MUST BE driven at the same state, else you'll short
77 circuit the output buffers! So plugging the I2C adapter after loading
78 the i2c-parport module might be a good safety since data line state
79 prior to init may be unknown.
81 - Obviously you cannot read SCL (so it's not really standard-compliant).
82 Pretty easy to add, just copy the SDA part and use another input pin.
83 That would give (ELV compatible pinout):
87 Side ______________________________Vdd (+) Side
96 SCL ----------x--------x--| o---x------------------------ pin 15
100 | ---o |-------------x-------------- pin 2
105 SDA ---------------x---x--| o--------x------------------- pin 10
109 ---o |------------------x--------- pin 3
122 If possible, you should use the same pinout configuration as existing
123 adapters do, so you won't even have to change the code.
126 Similar (but different) drivers
127 -------------------------------
129 This driver is NOT the same as the i2c-pport driver found in the i2c package.
130 The i2c-pport driver makes use of modern parallel port features so that
131 you don't need additional electronics. It has other restrictions however, and
132 was not ported to Linux 2.6 (yet).
134 This driver is also NOT the same as the i2c-pcf-epp driver found in the
135 lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port
136 as an I2C bus directly. Instead, it uses it to control an external I2C bus
137 master. That driver was not ported to Linux 2.6 (yet) either.
140 Legacy documentation for Velleman adapter
141 -----------------------------------------
144 Velleman http://www.velleman.be/
145 Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html
147 The project has lead to new libs for the Velleman K8000 and K8005:
148 LIBK8000 v1.99.1 and LIBK8005 v0.21
149 With these libs, you can control the K8000 interface card and the K8005
150 stepper motor card with the simple commands which are in the original
151 Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and
152 many more, using /dev/velleman.
153 http://home.wanadoo.nl/hihihi/libk8000.htm
154 http://home.wanadoo.nl/hihihi/libk8005.htm
155 http://struyve.mine.nu:8080/index.php?block=k8000
156 http://sourceforge.net/projects/libk8005/