fhem.pl - Hints for GNU/Linux

One device
If you connect one USB device (FHZ1000PC, FHZ1300PC, EM1010PC, WS300, ...) to your GNU/Linux server you can use the regular ftdi_sio kernel module. However, it may not recognize our device. Therefore you need to get the vendor and product codes:
# lsusb
...
Bus 002 Device 002: ID 0403:e0e8 Future Technology Devices International, Ltd
...

Now you need to edit your /etc/modprobe.conf or /etc/modprobe.conf.local file (depending on your distribution). Add the following line to it:

options ftdi_sio vendor=0x0403 product=0xe0e8

Replace the vendor and product code with the output of the lsusb command. The you load the module using:

# modprobe ftdi_sio

Multiple devices
If you're using multiple USB devices (FHZ1000PC, FHZ1300PC, EM1010PC, WS300, ...) you cannot use the methode above. You need to modify the ftdi_sio kernel module to make it work. The following example was done with openSuSE 10.1:
You need to have the kernel-source-version RPM of your current kernel (see output of uname -r) installed.

# cd /usr/src/linux
# make cloneconfig
# make modules_prepare
# cp /boot/symvers-2.6.*-default.gz /usr/src/linux
# mv symvers-2.6.*-default.gz Module.symvers.gz
# gunzip /usr/src/linux/Module.symvers.gz
# make modules_prepare
# cd drivers/usb/serial
 For the EM1010PC you (may) need to add the following line:
# vi ftdi_sio.h
...
#define FTDI_ELV_WS500_PID 0xE0E9 /* PC-Wetterstation (WS 500) */
#define FTDI_ELV_EM1010PC_PID 0xE0EF /* EM 1010 PC */

Now we need to uncomment some lines to enable all of our devices.
# vi ftdi_sio.c
...
{ USB_DEVICE(FTDI_VID, FTDI_ELV_WS300PC_PID) },
{ USB_DEVICE(FTDI_VID, FTDI_ELV_FHZ1300PC_PID) },
{ USB_DEVICE(FTDI_VID, FTDI_ELV_WS500_PID) },
{ USB_DEVICE(FTDI_VID, FTDI_ELV_EM1010PC_PID) },
...

Remove the /* and */ of your devices and save the file.
# cd /usr/src/linux
 Now you have 3 choices:

# mv Module.symvers Module.symvers.notneeded
# make M=drivers/usb/serial 		... to build the modules for all of usb serial.
If you have a less powerfull machine like the ARM-Based NSLU2 then it is sufficient to only build the required module.
# make modules ... to build all modules (takes a long time).
# make driver/usb/serial/ftdi_sio.ko ... to build just the ftdi_sio.ko module. However, this does not seem to be working always.
Once you have the module:

# cd /lib/modules/yourKernelVerion/kernel/drivers/usb/serial
# cp ftdi_sio.ko ftdi_sio.ko_backup
# cp /usr/src/linux/drivers/usb/serial/ftdi_sio.ko .

To make it become active you may need to stop applications (like fhem) who are using the /dev/ttyUSB device and unload the module and load it again.

# rmmod ftdi_so
# modprobe ftdi_so

You should now see multiple ttyUSB devices:
# ls -l /dev/ttyUSB*
crw-rw---- 1 root uucp 188, 0 2007-02-11 23:00 /dev/ttyUSB0
crw-rw---- 1 root uucp 188, 1 2007-02-11 23:00 /dev/ttyUSB1

Device links
If you're using multiple USB devices (FHZ, EM, WS...) it might occur that the enumeration of the /dev/ttyUSBn numbers get mixed up if one of the device is missing or after a reboot.
Starting with kernel 2.6 the UDEV implements means for using virtual names instead of the bare numbers.
Edit the file /etc/udev/rules.d/50-udev-default.rules and append the following lines in the block labled as serial devices:
KERNEL=="ttyUSB*", SYSFS{product}=="ELV FHZ 1300 PC", SYMLINK+="elv_fhz1300pc"
KERNEL=="ttyUSB*", SYSFS{product}=="ELV EM 1010 PC", SYMLINK+="elv_em1010pc"

Now you need to reboot your box (unfortunalty) and once the system has come up again you can use the device paths /dev/elv_fhz1300pc or /dev/elv_em1010pc in your FHEM configuration file.