reading touch screen device (/dev/input/event0)

Dear Experts,

I am developing a simple touch screen based application in Linux C on fc12
platform, where I have some trouble while reading the device driver for
touch screen /dev/input/event0. My code is as follows,

#include<stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include<stdlib.h>

main()
{
        int fileno = open("/dev/input/event0",O_RDONLY),num_bytes;
        char ev[50];
        num_bytes = read(fileno,ev,50);
  if(num_bytes<=0)
        {
              perror("Cannot access");
              exit(FAILURE);
  }
        printf("%d\n",fileno);
        printf("\nNumber of bytes read is %d\n string is
%s\n",num_bytes,ev);
  close(fileno);
}

1> Opening the port successfully
2> Reading the port successfully
3> Closing the port successfully

But, the values read are garbage. How can I read the touch co-ordinates of
the touch screen successfully. The debug information sent as an attachment.

With Regards.

struct input_event ev;
num_bytes=read(fileno,&ev,sizeof(struct input_event));

Depending on ev.type and ev.code you will get either X, Y coordinate or
other information.

Dear Sir,

Can I know in which header file this struct input_event is declared, so
that i can define it with ev variable.

Thank You.

With Regards,
Be Embedded.

Simply do a look into this tool:

http://enialis.net/~jrd/salix/evtest/1.25-i486-1cp/evtest-1.25.tar.bz2

Dear Experts,

How to calculate the touch screen co-ordinates from the members of 
struct input_event ev; ie (ev.code & ev.type).

With Regards.

You should use the tslib (refer git://github.com/kergoth/tslib.git)

ok i can read the ABS_X and ABS_Y under the event ABS for the mini2440 (240
X 320 pixel size). However, the coordinates I am getting are unexpected.
for the upper left corner i am getting (929,111), for upper right
(111,111), lower left (929,929) and lower right (110, 929).

do i need to do any conversion to get the right coordinates. I suppose the
upper left corner is (0,0)

anyways i solved it............... if anyone is interested then have a look
at it here.........

http://www.ti.com/lit/an/slyt277/slyt277.pdf

http://www.embedded.com/design/configurable-systems/4023968/How-To-Calib...

Seems you re-invent tslib...