multiple touch screens

1

Dear Psychtoolbox community,


I am trying to set up a configuration with multiple touch screens; however, I am hitting a wall right now and am wondering if anybody did try this before and likes to share the experience.


Right now, I am testing with Xubuntu 18.04, and I was able to present stimuli on 5 different screens. I am failing in the configuration of the touch screens, tried to use xinput to map them to the corresponding screens. Xinput lists two touchscreens I have connected right now:


$ xinput --list

⎡ Virtual core pointer                    id=2 [master pointer  (3)]

⎜   ↳ Virtual core XTEST pointer              id=4 [slave  pointer  (2)]

⎜   ↳ Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB id=6 [slave  pointer  (2)]

⎜   ↳ Logitech USB Optical Mouse              id=9 [slave  pointer  (2)]

⎜   ↳ Weida Hi-Tech                CoolTouch System            id=10 [slave  pointer  (2)]

⎣ Virtual core keyboard                    id=3 [master keyboard (2)]

    ↳ Virtual core XTEST keyboard              id=5 [slave  keyboard (3)]

    ↳ Logitech USB Keyboard                    id=7 [slave  keyboard (3)]

    ↳ Logitech USB Keyboard                    id=8 [slave  keyboard (3)]


However, Matlab only recognizes one (and the Touchscreen demo works for this one):


>> GetTouchDeviceIndices()


ans =


     8


>> GetTouchDeviceInfo(8)


ans = 


  struct with fields:


    touchDeviceType: 1

     maxTouchpoints: 15

            product: 'Weida Hi-Tech                CoolTouch System           '

       serialNumber: []

         locationID: 2

      valuatorInfos: [1×4 struct]


The screens are configured as separate X server processes and this part works fine, but how can I use multiple touch screens as input devices? I tried options with xinput so far without success, I am looking into potential multi-seat configurations but get the impression that this is an overall outdated approach. 


Has anybody some pointers how to best approach this? Could it just be that the Elo Touchscreen is the troublemaker and does not work well with Linux?


Any help is much appreciated!


thanks,

wolf


2

Hello Wolf,

the internet suggests that touchscreen should work out of the box, so i assume it has something to do with your specific setup. Do you mean multiple X-Servers or multiple X-Screen's on *one* server? What's the bigger picture with this setup?

What is the output of d = PsychHID('Devices', 3) and of xinput list-props 6  ?
Does the mouse-cursor respond to single-touch on that Elo monitor?
Does it work in single-server, single-x-screen bog standard mode?

-mario

---In PSYCHTOOLBOX@yahoogroups.com, <wolf.zinke@...> wrote :

Dear Psychtoolbox community,


I am trying to set up a configuration with multiple touch screens; however, I am hitting a wall right now and am wondering if anybody did try this before and likes to share the experience.


Right now, I am testing with Xubuntu 18.04, and I was able to present stimuli on 5 different screens. I am failing in the configuration of the touch screens, tried to use xinput to map them to the corresponding screens. Xinput lists two touchscreens I have connected right now:


$ xinput --list

⎡ Virtual core pointer                    id=2 [master pointer  (3)]

⎜   ↳ Virtual core XTEST pointer              id=4 [slave  pointer  (2)]

⎜   ↳ Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB id=6 [slave  pointer  (2)]

⎜   ↳ Logitech USB Optical Mouse              id=9 [slave  pointer  (2)]

⎜   ↳ Weida Hi-Tech                CoolTouch System            id=10 [slave  pointer  (2)]

⎣ Virtual core keyboard                    id=3 [master keyboard (2)]

    ↳ Virtual core XTEST keyboard              id=5 [slave  keyboard (3)]

    ↳ Logitech USB Keyboard                    id=7 [slave  keyboard (3)]

    ↳ Logitech USB Keyboard                    id=8 [slave  keyboard (3)]


However, Matlab only recognizes one (and the Touchscreen demo works for this one):


>> GetTouchDeviceIndices()


ans =


     8


>> GetTouchDeviceInfo(8)


ans = 


  struct with fields:


    touchDeviceType: 1

     maxTouchpoints: 15

            product: 'Weida Hi-Tech                CoolTouch System           '

       serialNumber: []

         locationID: 2

      valuatorInfos: [1×4 struct]


The screens are configured as separate X server processes and this part works fine, but how can I use multiple touch screens as input devices? I tried options with xinput so far without success, I am looking into potential multi-seat configurations but get the impression that this is an overall outdated approach. 


Has anybody some pointers how to best approach this? Could it just be that the Elo Touchscreen is the troublemaker and does not work well with Linux?


Any help is much appreciated!


thanks,

wolf


 
3
Hi Mario,

Thanks for the reply. I attached a screenshot with the Nvidia configuration where I also had two additional display only screens attached. I run them as X screens, and it is possible to control stimulus presentation on all screens. This part was working unexpectedly easy and fine. At the moment I am testing without the LG monitors attached. The PC has two Nvidia Quadro P1000 cards, and I am aiming for connecting 6 touch screens plus the main control screen. The ideas is to have a large field stimulus display and recognize screen touches on a screen relative to presented stimuli. Hence I need to be able to control stimulus display independently (which worked) and recognize touches on the corresponding screens (which I am struggling with).

cheers,
wolf

Here are the outputs:

~$ xinput list-props 6
Device 'Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB':
Device Enabled (153): 1
Coordinate Transformation Matrix (155): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Natural Scrolling Enabled (284): 0
libinput Natural Scrolling Enabled Default (285): 0
libinput Calibration Matrix (286): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Calibration Matrix Default (287): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Left Handed Enabled (288): 0
libinput Left Handed Enabled Default (289): 0
libinput Send Events Modes Available (290): 1, 0
libinput Send Events Mode Enabled (291): 0, 0
libinput Send Events Mode Enabled Default (292): 0, 0
Device Node (293): "/dev/input/event0"
Device Product ID (294): 1255, 32
libinput Drag Lock Buttons (295): <no items>
libinput Horizontal Scroll Enabled (296):

~$ xinput list-props 10
Device 'Weida Hi-Tech                CoolTouch System           ':
Device Enabled (153): 1
Coordinate Transformation Matrix (155): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Calibration Matrix (286): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Calibration Matrix Default (287): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Send Events Modes Available (290): 1, 0
libinput Send Events Mode Enabled (291): 0, 0
libinput Send Events Mode Enabled Default (292): 0, 0
Device Node (293): "/dev/input/event4"
Device Product ID (294): 9589, 34643

And in Matlab:

>> d = PsychHID('Devices', 3)
d = 
  1×4 struct array with fields:
[...]
>> {d.product}'
ans =
  4×1 cell array

    {'Virtual core XTEST pointer'                                      }
    {'Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB'}
    {'Logitech USB Optical Mouse'                                      }
    {'Weida Hi-Tech                CoolTouch System           '        }
>> d(2)
ans = 
  struct with fields:

     usagePageValue: 1
         usageValue: 2
          usageName: 'slave pointer'
              index: 4
          transport: 'enabled'
           vendorID: []
          productID: []
            version: []
       manufacturer: []
            product: 'Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB'
       serialNumber: []
         locationID: 2
        interfaceID: 6
      totalElements: 11
           features: 7
             inputs: 11
            outputs: 0
        collections: 0
               axes: 4
            buttons: 7
               hats: 0
            sliders: 0
              dials: 0
             wheels: 0
    touchDeviceType: -1
     maxTouchpoints: -1
>> d(4)
ans = 
  struct with fields:

     usagePageValue: 1
         usageValue: 2
          usageName: 'slave pointer'
              index: 8
          transport: 'enabled'
           vendorID: []
          productID: []
            version: []
       manufacturer: []
            product: 'Weida Hi-Tech                CoolTouch System           '
       serialNumber: []
         locationID: 2
        interfaceID: 10
      totalElements: 11
           features: 6
             inputs: 11
            outputs: 0
        collections: 0
               axes: 4
            buttons: 7
               hats: 0
            sliders: 0
              dials: 0
             wheels: 0
    touchDeviceType: 1
     maxTouchpoints: 15



4
Hi,

I did disconnect all screens except the Elo Touch screen. This way it is possible to calibrate the screen with xinput_calibrator:

Section "InputClass"
Identifier "calibration"
MatchProduct "Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB"
Option "MinX" "33"
Option "MaxX" "4068"
Option "MinY" "-8"
Option "MaxY" "3883"
Option "SwapXY" "0" # unless it was already set to 1
Option "InvertX" "0"  # unless it was already set
Option "InvertY" "0"  # unless it was already set
EndSection

MultiTouchDemo
However, Matlab does not recognize this device as a touch screen, for example when I try to run the MultiTouchDemo I get this error:

PTB-INFO: Real resolution of (rather low resolution!) system clock is 1000.0000 microseconds, dynamic sleepwait_threshold starts with 10.000000 msecs...
No touch input device found, or invalid dev given. Bye.
 


wolf
5
I'll look a bit into this later this evening. But afaics the touchscreen does not get classified as a touchscreen, but as a mouse, hence it doesn't show up as touchscreen.

Some googling suggests the Intellitouch 2700 series, being apparently a rather old product, uses controller chips which do not support the industry standard USB-HID multitouch protocol, but something ELO proprietary, so they are not supported by standard USB touchscreen drivers and will need special treatment. Probably your touchscreen literally tells the OS "I'm a mouse, treat me like that.", so it works for driving the mouse pointer, but nothing else. There may exist special drivers or config to fix this, or one could use the advanced mouse support of Linux KbQueue interface to get at least single-touch input from that ELO screen, although it would make for awkward coding if you need different non-touch-screen code to handle the ELO vs. the other touch screen(s).

Anyway, need to look a bit closer and don't have time in the next hours.

However, that clock resolution message suggests some timing weirdness on your system. Also with the NVidia proprietary graphics driver it will be impossible to get high precision visual stimulus timestamping to work on your setup with dual-NVidia ie. for more than 4 displays, and getting it to work on 4 displays might be near-impossible or at least painful to set up, so i hope for you that millisecond or frame-accurate visual timing won't matter to your paradigm.

For this kind of setup - just as for any other demanding setup - i strongly recommend suitable AMD graphics cards with their well designed open-source drivers and the abiity to driver up to six displays simultaneously without compromising timing or other hacks, unless there is a strong reason to choose NVidia -- the only one i can think of atm. is if one needs CUDA compute ability.

-mario

6
Hi Mario,

Thanks again for looking into this.

I did the steps you described. I pasted the Elo related content from the most recent Xorg.0.log file (/var/log/) below.  Adding the line to /etc/udev/rules.d/psychtoolbox.rules did not affect the Xorg log file, it reads the same, and accordingly, Psychtoolbox does not recognize this additional touchscreen.

We decided to go with different touch devices to avoid this hassle, therefore it might just be enough to flag the Elo touchscreens as problematic with Psychtoolbox.

cheers,
wolf
 
[...]
[     4.877] (II) config/udev: Adding input device Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB (/dev/input/event1)
[     4.877] (**) Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: Applying InputClass "libinput pointer catchall"
[     4.877] (II) Using input driver 'libinput' for 'Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB'
[     4.877] (**) Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: always reports core events
[     4.877] (**) Option "Device" "/dev/input/event1"
[     4.877] (**) Option "_source" "server/udev"
[     4.929] (II) event1  - Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: is tagged by udev as: Mouse
[     4.929] (II) event1  - Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: device is a pointer
[     4.929] (II) event1  - Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: device removed
[     4.939] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/0003:04E7:0020.0003/input/input4/event1"
[     4.939] (II) XINPUT: Adding extended input device "Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB" (type: MOUSE, id 12)
[     4.939] (**) Option "AccelerationScheme" "none"
[     4.939] (**) Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: (accel) selected scheme none/0
[     4.939] (**) Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: (accel) acceleration factor: 2.000
[     4.939] (**) Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: (accel) acceleration threshold: 4
[     4.991] (II) event1  - Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: is tagged by udev as: Mouse
[     4.991] (II) event1  - Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB: device is a pointer
[     4.991] (II) config/udev: Adding input device Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB (/dev/input/js1)
[     4.991] (II) No input driver specified, ignoring this device.
[     4.991] (II) This device may have been added with another device file.
[     4.991] (II) config/udev: Adding input device Elo TouchSystems, Inc. Elo TouchSystems 2700 IntelliTouch(r) USB (/dev/input/mouse1)
[     4.991] (II) No input driver specified, ignoring this device.
[...]