Thread: Lilliput 8" touch screen backwards - FC4

Originally Posted by DJBigShow

Hi all,

I recently installed Fedora Core 4 on my Mac Mini, and am using a Lilliput 8" touch screen on it. It detects the touchscreen as an eGalaxy screen, and installs the touchkitusb kernel module for it. However, the X and Y axis seems to be backwards: When I touch on the top left corner of the screen, the cursur goes to the bottom right corner of the screen.

Thinking it was an Endianess problem (i.e. intel vs. ppc) I tired it on an intel fedora core 4 system, and the same thing happens!

Does anyone have any ideas? I am about to dive into the kernel module itself and attempt to figure it out, but I've seen other posts where people have this same screen working fine under Linux. Is it possible this is a newer model (just purchased) and is a bit different? Has anyone else had this problem?

By the way, when I boot into OS X and install eGalaxy's drivers, it works just fine, so it isn't the hardware.

Thanks,
-DJBS

It turns out that the USB touch screen driver that comes with Linux doesn't interprete the eeprom information from the eGalaxy touch screens, so it may work on some and won't work on others. Using the InvX and InvY (to invert the axis') I could get it work kind of work, but was unable to calibrate anything.

I downloaded the eGalaxy drivers for Fedora Core III (None available for FC4), and modified it to compile on FC4. I then had endianess issues -- the driver they wrote won't work on big endian. I fixed this, along with several other places in their user code where they assumed "-1" meant 255 (intel is inherently signed, whereas PPC is inherently unsigned).

Once I did all this, my touch screen works great! If anyone else plans to use their lilliput on Linux (intel or PPC), let me know and I'll help out with the kernel module and user space modifications required to work.

-DJBS

Hi,

It seems I have exactly the same problem. FC4 and the touch screen is not setup correctly. I had a look at the xfree86 howto regarding calibration but am consusfed becase I can't find a xorg.conf version.

Have downloaded the FC3 driver and am ready to go!

Aaran

Lilliput 7" Touch - EPIA 500 - FC4 - NMEA Serial GPS

Since kernel 2.6.10 or 2.6.11, a module parameter has existed for touchkitusb, which may solve the problem you originally had. I believe the parameter is swap_xy.

Maybe you could try that, as it would save some effort.

Also, I'm not using any downloaded drivers, just touchkitusb.

Ok will try that this afternoon. Have to remember where I set the module options :-) Do you calibrate manually? The appeal for using the tochkit was it included the calibration tool and includes some utility for right mouse clicking.

Will let you know how I get on.

I use gentoo, so I'm not sure if this is different: module parameters are set in \etc\modules.autoload.d\kernel-2.6. I think you just need to change the line that says touchkitusb to touchkitusb swap_xy, but I could be wrong. I have not actually had to use this option myself. If you use modprobe, I think the syntax is similar, but check the help or man page.

In terms of calibration, yes, I did a manual calibration. I am using DirectFB instead of X windows, so the calibration tool wasn't useful for me. I think at best, it might be useable in XDirectFB, but I did not try that option.

Hello

I am using Xandros 3.02 (Debian) with touchkitusb.

I had the issue with inverted X and y but I fixed this by running:

modprobe touchkitusb swap_xy

I also have a problem with the location of the stylus/finger being identified incorrectly.

Basically I am able to use the screen if I assume that the mousable area is only the top left hand quarter. Im not sure how to explain it, its kind of scaled up, its like using one of those old draughtsmans tools where you can draw a small drawing and it kindof manipulates a few arms with a pencil attatched to create a larger scal drawing ;-)

Any ideas?

Originally Posted by Jason_Bassett

Hello

I am using Xandros 3.02 (Debian) with touchkitusb.

I had the issue with inverted X and y but I fixed this by running:

modprobe touchkitusb swap_xy

I also have a problem with the location of the stylus/finger being identified incorrectly.

Basically I am able to use the screen if I assume that the mousable area is only the top left hand quarter. Im not sure how to explain it, its kind of scaled up, its like using one of those old draughtsmans tools where you can draw a small drawing and it kindof manipulates a few arms with a pencil attatched to create a larger scal drawing ;-)

Any ideas?

To me, it sounds like your calibration data is incorrect. Do you have a non-X program that is utilizing the touchscreen data, or are you using X Windows as your GUI? How are you doing a calibration?

To ensure that your touchscreen is functioning correctly throughout all portions of the screen, run cat /dev/input/eventX, where X is the touchscreen device number. Your keyboard, mouse, and touchscreen (if all connected), may have a separate eventX entry as well. Simply touch any part of your screen, and some garbage (random characters) should be output on the display. If you see nothing, try moving your mouse or typing on your keyboard to see if you chose the wrong eventX device. I have used this method before to ensure the kernel sees the touchscreen.

Good luck.

Hello

I use KDE.

I have not been able to use any calibration tools as all of the ones I have attempted to use appear correctly but the mouse cursor is not displayed within the calibration window (it appears fine when I drag it out of the calibration window)

cat /dev/input/event1 gives me the garbage. I found out that the touchscreen was on event1 by doing:

cat /proc/bus/input/devices which gave me amongst other text, this:

N: Name="eGalax Inc. USB TouchController"
P: Phys=usb-0000:00:1d.7-3.1/input0
H: Handlers=mouse0 ts0 event1

I have fiddled with the MaxX and MaxY etc but no luck.

Jason

Originally Posted by Jason_Bassett

Hello

I use KDE.

I have not been able to use any calibration tools as all of the ones I have attempted to use appear correctly but the mouse cursor is not displayed within the calibration window (it appears fine when I drag it out of the calibration window)

cat /dev/input/event1 gives me the garbage. I found out that the touchscreen was on event1 by doing:

cat /proc/bus/input/devices which gave me amongst other text, this:

N: Name="eGalax Inc. USB TouchController"
P: Phys=usb-0000:00:1d.7-3.1/input0
H: Handlers=mouse0 ts0 event1

I have fiddled with the MaxX and MaxY etc but no luck.

Jason

Your description of how the calibration program is working actually sounds correct. When calibrating my touchscreen, I have to touch specific parts on the screen (ie touch a red box in each corner of the screen). There is no need for a mouse cursor, especially during calibration. Read the help file if there is one for your calibration program. You must calibrate your touchscreen otherwise it will not work correctly, as you are now experiencing.

If you see garbage output no matter where you touch your touchscreen, that means it is most likely functioning correctly.

I would also suggest reading through this: http://linux.chapter7.ch/touchkit/mini-howto.txt and make sure you have everything setup correctly.