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segementation fault, digitizer problem

Hi,

Perhaps someone can help me to solve my digitizer problem.

I´m using  a calcomp drawing board III. It is connected to ttyS1(com2)
and works with Linux (Suse4.4). I can use it as a mice for example.
But when I try to use the digitizer in the program ´GRASS - v.digit
(geographic research analysis program)´ I get an error message :
segmentation fault.
I know that the program works fine and I´ve got the right digitizer
driver.
So I assume it is a hardware problem. In my linux box there is an Asus
P55 PCI board.

I tried to change the dram settings in the bios setup with the result
that sometimes appears an other error message when I run the GRASS
program. But this message wasn´t reproducible.

Do you have any suggestion. Perhaps you know a possibility to test the
tty-port when the program and the digitizer try to communicate.

Any hint is helpfull.

Thanks very, very much in advance and I´m sorry for my german-english.

Please reply by email

Christian

kerniebc@sp.zrz.tu-berlin.de
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spyglass
Asked:
spyglass
1 Solution
 
jlmsCommented:
The problems with digitizers  are of two kinds: the format of the data and the speed at which the data is sended.

To Isolate the problem follow these steps:

-Identify the format of the data required for your application: you have to check the manual of your program.

-Configure and test the digitizer:
  Check your digitizer's manual. Once you have configured it then test it, use this command:

cat /dev/ttyS1
or
cat /dev/ttyS1 > some_log_file (in case you need an constant stream of data)
and then press buttons and make movements  with the digitizer cursor and check that you are getting the information in the requested format. Be very careful with the cable that connects tha digitizer to your computer, some digitizers demand this cable to be shielded and the shield in contact with the metalic parts around the pins in both connectors. If you get the right format try
and the program still crashes the try changing the speed of the communication, this is particurlarly important if you have a constant stream of data. Check the Linux's setserial command ant how two change the samples/second in your digitizer.

-Check the software: if everything looks all right with the digitizer then try tracing your software. Try using the strace command to follow up the programs acctions. Maybe a permission is not set properly or a file somewhere is missing. Check that you have the exact requirements for your program (kernel version, libraries, X server, etc).
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