Elite Screens Universal Wireless 5-12 Volt Trigger for Projectors With
ViewSonic PX748-4K True 4K Projector with 4000 Lumens 240 Hz 4.2ms HDR Support Auto Keystone Dual HDMI and USB C for Home Theater Day and Night, Stream Netflix with Dongle Home Theater
HD11CTRL - HDMI In-line Controller with IR, RS-232, CEC, Signal Sensing & 12V Trigger Outputs - Prolites Sound, Light & Video
AV Amplifier Triggered HDMI Switch : 4 Steps - Instructables