Hi,

So I am setting up a new HMI device that runs a custom Yocto image with a basic X11 setup no desktop or anything.

In the file /usr/bin/mini-x-session there is the following two lines:

matchbox-terminal&
exec matchbox-window-manager

Now the terminal that opens up works and I can launch my other UI windows and so on without issue.

But lets set that at bootup I have a cron job that runs a script in the background that delays 10 minutes from bootup. This script then wants to open a new UI on top of the current terminal window that opened at bootup.

I know I can use:

startx /home/root/application

But I think that opens a new X11 instance as I use xset in the beginning to stop the display from turning off after 10min and once I use startx the display will once again turn on after 10min

Is this the proper way to start up an application inside an existing matchbox-window-manager instance?

For example the matchbox-window-manager has a keyboard shortcut to open a new matchbox-terminal. If I press that it will open the new terminal and then I can close that window and see the previous screen/terminal that was open.

Thats what I want to acheive. My display is 0.0 if that makes any difference.

Sorry if I am not super knowledgeable about this stuff I am new to HMI devices like this.

I have no experience with Yocto, but I suggest to try prefacing the launching of the application in the cron job with DISPLAY=:0. This has worked for me.