Some 10+ years ago on a small LAN party, we hooked up a tower PC to a projector to show some stats, last few lines of an IRC channel, those kind of things. For some reason, we directly started the application in X (the display system), but at regular intervals, the projector would stop working. Of course! Screen blanking. Having no window manager or other means* of controlling this, the projector would of course keep on displaying our lovely application if we would move the mouse once in a while, or type on the keyboard.
Instead of tasking someone to move the mouse once in a while, we taped a wired, optical mouse to the tower PC at the front. At the time, CD/DVD players were still abundant, so this PC also contained one. We did know about the eject(1) tool, as well as its option to close the tray again (eject -t). From that moment on, the solution for our screen blanking problem was fixed:
while true; do eject /dev/cdrom; sleep 5; eject -t /dev/cdrom; sleep 30; done;
(this would eject the CD/DVD drive, wait five seconds, then close it again, and wait 30 seconds before starting the same sequence again)
This would cause the optical mouse to detect movement, send this to the PC, and in the end keep the projector on.
* we would later discover the xset(1) tool and its DPMS/screen saver settings. But that would've eliminated the periodic, comedic noise of the CD/DVD drive and the wired mouse bumping on the tower PC, so we kept the while loop intact during the rest of the LAN party.
Instead of tasking someone to move the mouse once in a while, we taped a wired, optical mouse to the tower PC at the front. At the time, CD/DVD players were still abundant, so this PC also contained one. We did know about the eject(1) tool, as well as its option to close the tray again (eject -t). From that moment on, the solution for our screen blanking problem was fixed:
(this would eject the CD/DVD drive, wait five seconds, then close it again, and wait 30 seconds before starting the same sequence again)This would cause the optical mouse to detect movement, send this to the PC, and in the end keep the projector on.
* we would later discover the xset(1) tool and its DPMS/screen saver settings. But that would've eliminated the periodic, comedic noise of the CD/DVD drive and the wired mouse bumping on the tower PC, so we kept the while loop intact during the rest of the LAN party.