Code to control various montiors using an arduino with IR (and possibly Bluetooth). Used NPN transistors as switches (except in one case). The emitters were all connceted to the monitor ground, the collect was solder to the monitor button and an arduino output pin was connceted to the base of each transistor. Configured as such the transistor acts as a switch "pressing the button" by connceting it to ground.
Will try to post full guide soon.