| Kernel driver i2c-parport |
| |
| Author: Jean Delvare <khali@linux-fr.org> |
| |
| This is a unified driver for several i2c-over-parallel-port adapters, |
| such as the ones made by Philips, Velleman or ELV. This driver is |
| meant as a replacement for the older, individual drivers: |
| * i2c-philips-par |
| * i2c-elv |
| * i2c-velleman |
| * video/i2c-parport (NOT the same as this one, dedicated to home brew |
| teletext adapters) |
| |
| It currently supports the following devices: |
| * Philips adapter |
| * home brew teletext adapter |
| * Velleman K8000 adapter |
| * ELV adapter |
| * Analog Devices evaluation boards (ADM1025, ADM1030, ADM1031, ADM1032) |
| |
| These devices use different pinout configurations, so you have to tell |
| the driver what you have, using the type module parameter. There is no |
| way to autodetect the devices. Support for different pinout configurations |
| can be easily added when needed. |
| |
| |
| Building your own adapter |
| ------------------------- |
| |
| If you want to build you own i2c-over-parallel-port adapter, here is |
| a sample electronics schema (credits go to Sylvain Munaut): |
| |
| Device PC |
| Side ___________________Vdd (+) Side |
| | | | |
| --- --- --- |
| | | | | | | |
| |R| |R| |R| |
| | | | | | | |
| --- --- --- |
| | | | |
| | | /| | |
| SCL ----------x--------o |-----------x------------------- pin 2 |
| | \| | | |
| | | | |
| | |\ | | |
| SDA ----------x----x---| o---x--------------------------- pin 13 |
| | |/ | |
| | | |
| | /| | |
| ---------o |----------------x-------------- pin 3 |
| \| | | |
| | | |
| --- --- |
| | | | | |
| |R| |R| |
| | | | | |
| --- --- |
| | | |
| ### ### |
| GND GND |
| |
| Remarks: |
| - This is the exact pinout and electronics used on the Analog Devices |
| evaluation boards. |
| /| |
| - All inverters -o |- must be 74HC05, they must be open collector output. |
| \| |
| - All resitors are 10k. |
| - Pins 18-25 of the parallel port connected to GND. |
| - Pins 4-9 (D2-D7) could be used as VDD is the driver drives them high. |
| The ADM1032 evaluation board uses D4-D7. Beware that the amount of |
| current you can draw from the parallel port is limited. Also note that |
| all connected lines MUST BE driven at the same state, else you'll short |
| circuit the output buffers! So plugging the I2C adapter after loading |
| the i2c-parport module might be a good safety since data line state |
| prior to init may be unknown. |
| - This is 5V! |
| - Obviously you cannot read SCL (so it's not really standard-compliant). |
| Pretty easy to add, just copy the SDA part and use another input pin. |
| That would give (ELV compatible pinout): |
| |
| |
| Device PC |
| Side ______________________________Vdd (+) Side |
| | | | | |
| --- --- --- --- |
| | | | | | | | | |
| |R| |R| |R| |R| |
| | | | | | | | | |
| --- --- --- --- |
| | | | | |
| | | |\ | | |
| SCL ----------x--------x--| o---x------------------------ pin 15 |
| | | |/ | |
| | | | |
| | | /| | |
| | ---o |-------------x-------------- pin 2 |
| | \| | | |
| | | | |
| | | | |
| | |\ | | |
| SDA ---------------x---x--| o--------x------------------- pin 10 |
| | |/ | |
| | | |
| | /| | |
| ---o |------------------x--------- pin 3 |
| \| | | |
| | | |
| --- --- |
| | | | | |
| |R| |R| |
| | | | | |
| --- --- |
| | | |
| ### ### |
| GND GND |
| |
| |
| If possible, you should use the same pinout configuration as existing |
| adapters do, so you won't even have to change the code. |
| |
| |
| Similar (but different) drivers |
| ------------------------------- |
| |
| This driver is NOT the same as the i2c-pport driver found in the i2c |
| package. The i2c-pport driver makes use of modern parallel port features so |
| that you don't need additional electronics. It has other restrictions |
| however, and was not ported to Linux 2.6 (yet). |
| |
| This driver is also NOT the same as the i2c-pcf-epp driver found in the |
| lm_sensors package. The i2c-pcf-epp driver doesn't use the parallel port as |
| an I2C bus directly. Instead, it uses it to control an external I2C bus |
| master. That driver was not ported to Linux 2.6 (yet) either. |
| |
| |
| Legacy documentation for Velleman adapter |
| ----------------------------------------- |
| |
| Useful links: |
| Velleman http://www.velleman.be/ |
| Velleman K8000 Howto http://howto.htlw16.ac.at/k8000-howto.html |
| |
| The project has lead to new libs for the Velleman K8000 and K8005: |
| LIBK8000 v1.99.1 and LIBK8005 v0.21 |
| With these libs, you can control the K8000 interface card and the K8005 |
| stepper motor card with the simple commands which are in the original |
| Velleman software, like SetIOchannel, ReadADchannel, SendStepCCWFull and |
| many more, using /dev/velleman. |
| http://home.wanadoo.nl/hihihi/libk8000.htm |
| http://home.wanadoo.nl/hihihi/libk8005.htm |
| http://struyve.mine.nu:8080/index.php?block=k8000 |
| http://sourceforge.net/projects/libk8005/ |