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How to use a usb-serial converter with Serial Analyzer or JcGpsSimulator in Linux

April 2011, by Mario and Crovy

Revision April 2011 (by Crovy), from version 2.7.0 of the Serial Analyzer does not use libraries JavaComm but the most current RXTX.

These libraries will automatically manage the USB-serial adapter recognized by Linux as "ttyUSBx" (where x is the number of the adapter).

The article is still valid to explain the principles and the JcGpsSimulator which still uses the libraries "JavaComm.

Using a usb-serial converter means that it is recognized by both Linux, Serial Analyzer or JcGpsSimulator.

Concerning the first point, most Linux distributions have already driver to manage basic converters usb-serial but you must know how to make them available. The less experienced might have some difficulty because, in the absence of software "high level" and the recognition occurs without any apparent notice (in perfect style Linux) then you need to know where to look.

To see if the system recognizes the device, you must remember that Linux manages all devices using the special device file, in the system folder /dev.

When you insert a usb-serial converter into a USB port of your PC, the system recognizes them and adds a new file in the folder /dev. Possile then proceed as follows:

  • remove any usb-serial converter from the USB port of PC
  • issue the commands:

    cd /dev

    ls -l > /tmp/list1.txt

  • insert usb-serial converter in a usb door and wait some seconds
  • issue the commands:

    ls -l > /tmp/list2.txt

    diff /tmp/list1.txt /tmp/list2.txt

  • displayed in rows look for a file with the name similar to ttyUSB0 (may change the final number), that is the device that allows the use of usb-serial converter.

At this point you must make it visible to Serial Analyzer or JcGpsSimulator.

Like any Java program, the Serial Analyzer manages the serial ports by the library JavaComm. The driver JavaComm used by Serial Analizer recognizes as serial ports only devices that have as their name:

ttyS0 (the first serial port COM1)

ttyS1 (second serial port COM2)

ttyS2 (third serial port COM3)

ttyS3 (fourth serial port COM4)

The limit of the 4 serial ports means that if you already have 4 really exist, you'll have to give up one of them. Suppose you want to get rid of the fourth serial port (ttyS3), then you must give the commands:

  • sudo rm ttyS3
  • enter the password for the root
  • ln -s ttyUSB0 ttyS3

If, as happens often in recent portable PC, do not have any serial port, then you can use the name that identifies ttyS0 the first serial port directly and give the command

  • ln -s ttyUSB0 ttyS0

in both cases the ln command creates a symbolic link, namely a file called ttyS0 (or ttyS3 in the first instance) that points to ttyUSB0.

Now if you start Serial Analyzer you will see the presence of the first serial port (or fourth in the first instance) and use it as any serial port.

How to access EXT2 disk with Windows

October 2008, by Crovy

Who uses Linux may have to access from Windows to a disk formatted with the file system EXT2 or EXT3.

This Ext2IFS free program, installed in Windows, allows you to access at EXT2 disk.

After installation we will see our EXT2 disk as any other disk of Windows.

Please read the faq and warnings before using this driver.