PREH POS Keyboards


Preh USB Keyboard and Linux (i386)

Installation Notes

Version January 15 2004

Overview

The following instructions describe how you correctly set up the Preh USB keyboard wich is connected to the USB interface of an Linux(i386) computer. Especially if you want to communicate with the keyboard's modules these steps have to be executed correctly first.

If your Preh USB Keyboard is connected via USB to your computer, basically no special driver is needed, nor the kernel has to be modified.
 
Note:
Only if the USB kernel module 'hid' on your system does not have enough control_fifo_buffer, a modification and recompilation of this module may be necessary. Especially if you want to communicate with the keyboard module 'ToneIndicator' this modification is recommended.

System requirements


Package Contents

This package includes:

Installation Procedure

Important note:
Steps 1 .. 5 are only necessary, if you want to use the keyboard module "ToneIndicator" on standard Kernel 2.4.x.
Those improvements regarding "control_fifo_buffer" were in the meantime also included in the standard kernel 2.5.x and higher.
So, if you don't need to do these modifications, go directly to step 6 and run the Preh setup script.

To set up the USB environment for Preh USB keyboard usage under Linux, please follow this procedure:

  1. Log in as "root"
  2. Open the kernel file usr/src/linux/drivers/usb/hid.h to modify:
  3. Search for this text: HID_CONTROL_FIFO_SIZE
    If necessary, increase this value to at least 32, as described below:

    /* #define HID_CONTROL_FIFO_SIZE        8 */
    /* changed by PREH, lost some bytes if write data to Preh-HID-device */
    #define HID_CONTROL_FIFO_SIZE   32

  4. Save the modified file.
  5. change to directory /usr/src/linux/
  6. execute make modules (this might take a while)
     
  7. log in as "normal" user and change to the Preh JavaPOS subdirectory .../PrehJavaPos.1.6.0.xx/setup
  8. run the Preh JavaPOS setup script: ./setup
  9. Follow the wizard.

Notes on the Preh JavaPOS "setup" script:
When you select "USB", the Preh JavaPOS setup script will automatically generate the necessary HID devicenames used by Preh JavaPOS.
Additionally the symbolic links to "libPrehJPOS.so" are set up and the keyboard type is configured.

Additional steps - Usually obsolete

To use USB HID devices under Linux some basic settings are required in the Linux kernel configuration. Basically all new distributions install a kernel which has built in these settings already.
Therefore the following steps are normally obsolete if you're using a "up-to-date" distribution such as RedHat 8.0 or SuSE 8.2.

If your kernel does not already have full HID device support you have to add the HID support using a procedure as described below. After that you can go on with the normal installation procedure described above.

  1. Log in as "root"
  2. change to directory /usr/src/linux/
  3. call make menuconfig or any other kernel configuration utility
  4. set Input core support to:
            <M> Input core support
            <M> Keyboard support
            <M> Mouse support
            <M> Joystick support
            <M> Event interface support
  5. set USB support to:
            .
            --- USB Human Interface Devices (HID)
            <M> USB Human Interface Device (full HID) support
            [y] HID input layer support
            [y] /dev/hiddev raw HID device support
  6. Compile your kernel
  7. Compile the kernel modules
  8. Add the new kernel to your boot manager
  9. After you have done all this changes reboot your system!

If you should have any problems on installing and using these drivers we of course will like to help you. Also if you have any comments or suggestions to improve our drivers and installation scripts please email to: tech-support@preh.de. Further informations and latest drivers you can find in the internet at www.preh.com