Touch events are sent to HDMI

[psamim]

Hi,

I have touch display and HDMI connected to my device and both are working. But touch input works for HDMI and I cannot work with the LCD display. I mean tapping on touch LCD display produces a mouse click on HDMI display. Is there anything I should do?

Thanks,
Samim

[topguy]

What software is running on each display ? The touch is just another mouse input device its the software that is going to use it or not.

[psamim]

I have set my default display to HDMI by adding "display_default_lcd=0" to /mnt/config.txt.

I start x server and Firefox on HDMI and touch display shows black screen. But the touch input works and sends input to the Firefox and I can interact with anything on HDMI by the touch input.

Then I run sample Qt app on the LCD display by setting VC_DISPLAY env var. But still the same, I cannot interact with the app running on the LCD screen, touch inputs are sent to HDMI.

I believe there must be somewhere to configure this.

[ghans]

The HDMI output on the Raspberry Pi does not support transfer of touch events into the Pi. How
are the touch events transferred into the Pi ? USB cable ? Serial connection ?

ghans

[topguy]

I have set my default display to HDMI by adding "display_default_lcd=0" to /mnt/config.txt.

I start x server and Firefox on HDMI and touch display shows black screen. But the touch input works and sends input to the Firefox and I can interact with anything on HDMI by the touch input.
Then I run sample Qt app on the LCD display by setting VC_DISPLAY env var. But still the same, I cannot interact with the app running on the LCD screen, touch inputs are sent to HDMI.

I believe there must be somewhere to configure this.

The X-server will use all available input devices. It doesnt know that the touch-mouse is on a another display. I'm not sure if it use it in some exclusive mode, but it might prevent other programs from receiving the same input. ( Becase mouse events will be sent to X-based programs through the X protocol. )

The Qt program might need be told which input to be used. More info here: http://doc.qt.io/qt-5/embedded-linux.html#input

[psamim]

The HDMI output on the Raspberry Pi does not support transfer of touch events into the Pi. How
are the touch events transferred into the Pi ? USB cable ? Serial connection ?

Touch input is from the touch LCD display, and X is drawing on HDMI ourput.