Four types of hdmi grabber tests (hdmi-cec, rainbow signal) - Hardware Support - Hyperion-Project Forum
Can't figure out if there is a HDMI-CEC setting on tv. I have the Costco TCL 55S434 and plugged Roku Streambar Pro into the HDMI (ARC) and I can't power it on/off
What Is HDMI-CEC (Consumer Electronics Control)? - The Tech Edvocate