If you are referring to the IR functionality of some Roku remotes, they only have codes for TVs. They can't control soundbars, AVRs or projectors, unless those devices have some sort of CEC functionality. The volume control and power button on my Ultra remote will power off (but not on) my AVR and control the volume, but it's done via HDMI-CEC. Since the TV is in the same HDMI chain, powering off the AVR also powers off the TV. And pressing the Home button on the Roku remote will power on the TV and AVR if they are turned off.
But as far as programming your Roku remote to control your projector using the IR functions, that unfortunately will not be possible.
Dan
Roku Community Streaming Expert
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