Getting Started — CEC Adapter

This guide is for installers and end users setting up a Pulse-Eight CEC Adapter for the first time. It covers connecting the hardware, installing libCEC, and choosing the right automation method for your setup. The USB-CEC Adapter and NUC HDMI-CEC Adapter are not the same product and are not interchangeable — check which one you have before following the hardware steps below.

Before You Start

Which Adapter Do You Have?

If you're not sure which one you have, the USB-CEC Adapter is the small external dongle with two HDMI ports; the NUC HDMI-CEC Adapter is an internal card fitted inside the NUC chassis.

What You Need

• Your Pulse-Eight CEC Adapter (USB-CEC Adapter, or NUC HDMI-CEC Adapter with the correct cable harness for your NUC generation)
• Two HDMI cables (USB-CEC Adapter only) — one from your PC to the adapter, one from the adapter to your TV
• A CEC-enabled TV, with CEC switched on in the TV's settings menu
• A free USB port on your PC (USB-CEC Adapter only)
• A Windows, macOS, or Linux PC to install libCEC on

What CEC Lets You Do

Once set up, your adapter allows you to:

• Automatically turn your TV on when your PC starts or wakes
• Automatically turn your TV off when your PC shuts down or sleeps
• Use your TV remote to control media software on your PC (Kodi, Plex, etc.)
• Send custom CEC commands to your TV from scripts or automation software

For a full explanation of HDMI-CEC and what the adapter does, see What is the Pulse-Eight CEC Adapter and libcec?

Step 1 — Connect the Hardware

USB-CEC Adapter

NUC HDMI-CEC Adapter

The NUC HDMI-CEC Adapter fits internally and requires the cable harness matching your NUC generation. Fitting differs by model — follow the instructions for your specific NUC:

• Skull Canyon NUC CEC Adapter Instructions
• Hades Canyon NUC CEC Adapter Instructions
• 4th Gen Cable Harness for NUC HDMI-CEC Adapter
• 5th Gen Cable Harness for NUC HDMI-CEC Adapter
• 6th/7th/8th Gen Cable Harness for NUC HDMI-CEC Adapter

Step 2 — Install libCEC

libCEC is the software that lets the adapter communicate with your TV. The current release is 8.1.0 — check the downloads page for the latest version, as it can occasionally lag behind the GitHub release. Install libCEC for your operating system:

Step 3 — Test the Connection

Before setting up any automation, confirm the adapter is working correctly:

Windows:  tv_on.cmd Linux/macOS:  echo "on 0" | cec-client -s -d 1

If your TV turns on, the adapter and libCEC are both working correctly.

Step 4 — Choose Your Automation Method

There are several ways to use the adapter depending on what you want to achieve — turning the TV on with your PC, running as a background monitor, or scripting custom commands. See the comparison guide to choose the right one for your setup:

First Install Checklist

• Correct adapter identified (USB-CEC Adapter or NUC HDMI-CEC Adapter)
• Hardware connected — HDMI cables (or cable harness) fitted correctly
• CEC enabled in the TV's settings menu
• libCEC installed for your operating system
• Test command successfully turned the TV on
• Automation method chosen and configured
• Resolution/HDR requirements checked against adapter spec (USB-CEC Adapter)

Common First-Install Issues

Adapter not detected

Confirm the adapter is fully seated in the USB port (or correctly fitted internally for NUC units) and that libCEC is installed. Try a different USB port, and avoid unpowered USB hubs. See My CEC adapter isn’t working — Where do I start? for the full diagnostic flow.

TV doesn't turn on or off automatically

This is almost always a CEC setting or configuration issue rather than a hardware fault. Confirm CEC is enabled on the TV, that the correct HDMI input is being used, and that your chosen automation method (CEC-Tray, Standby Monitor, etc.) is actually running. Test manually with the command in Step 3 first to isolate hardware from configuration.

TV remote buttons don't control media playback

Some TV brands, notably certain Panasonic models, don't send standard CEC transport commands for play/pause/skip even with CEC enabled. 

Picture issues or no signal at 4K

The USB-CEC Adapter is rated for 4K@60Hz 4:2:0 8-bit. If you're running HDR10 or a higher colour depth, this is outside spec and can cause signal problems. Use the two-cable workaround described in USB-CEC Adapter — 4K Resolution to keep full CEC control while taking the adapter out of the main video path.

Next Steps

• Which TV Power Control Method Should I Use? — compare all available automation methods
• CEC Adapter — Using the LibCEC Standby Monitor
• CEC Adapter — How to Turn Your TV On When Your Windows 11 PC Boots Using CEC-Tray
• USB-CEC Adapter — 4K Resolution
• My CEC adapter isn’t working — Where do I start? — full troubleshooting flow if the adapter isn't detected