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phil d0d0bb35a4 Add fix command and troubleshooting for errno=16 error

- Add 'fix' command to diagnose CEC connection issues
- Add detailed troubleshooting section for common errors
- Fix handles errno=16 (device busy) by checking processes and trying sudo
- Document solutions for CEC permission and connection issues

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

2026-02-06 17:57:47 +01:00

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CEC Control for Raspberry Pi 4

Control HDMI-connected devices (TVs, receivers, etc.) from your Raspberry Pi 4 using CEC (Consumer Electronics Control).

Installation

Install the required CEC utilities:

sudo apt-get update
sudo apt-get install cec-utils

Make the script executable (already done):

chmod +x cec-control.sh

Usage

./cec-control.sh <command> [options]

Available Commands

Command	Description	Example
`tv-on`	Turn on the TV	`./cec-control.sh tv-on`
`tv-off`	Turn off the TV	`./cec-control.sh tv-off`
`standby`	Put TV in standby	`./cec-control.sh standby`
`wake`	Wake TV from standby	`./cec-control.sh wake`
`vol-up`	Increase volume	`./cec-control.sh vol-up`
`vol-down`	Decrease volume	`./cec-control.sh vol-down`
`mute`	Mute audio	`./cec-control.sh mute`
`input <port>`	Switch HDMI input (0-15)	`./cec-control.sh input 1`
`source <device>`	Switch source device (0-15)	`./cec-control.sh source 2`
`scan`	Scan for CEC devices	`./cec-control.sh scan`
`status`	Show CEC adapter status	`./cec-control.sh status`
`info`	Show TV information	`./cec-control.sh info`
`fix`	Troubleshoot connection issues	`./cec-control.sh fix`
`raw <command>`	Send raw CEC command	`./cec-control.sh raw 4f:82:10:00`
`help`	Show help message	`./cec-control.sh help`

Quick Start

Connect your Raspberry Pi to your TV via HDMI
Enable CEC on your TV (usually in settings)
Test the connection:

./cec-control.sh scan

Turn on your TV:

./cec-control.sh tv-on

Troubleshooting

Common Issues

ioctl CEC_S_MODE failed - errno=16 (Device or resource busy)

This error means something else is using the CEC device. Try these solutions:

Run the built-in fix command:

./cec-control.sh fix

Kill any existing CEC processes:

sudo killall cec-client

Check what's using the device:

sudo lsof /dev/cec0

Try running with sudo:

sudo ./cec-control.sh scan

If using Kodi or LibreELEC, CEC may be enabled in the application. Disable it or stop the application first.

CEC not working

Make sure CEC is enabled in your TV settings (often called "HDMI Control", "CEC Control", or branded names like "Bravia Link", "Anynet+", etc.)
Try a different HDMI port on your TV
Check that the HDMI cable is properly connected

Permission denied

Add your user to the video group: sudo usermod -aG video $USER
Then log out and back in
Or run with sudo

Device not found

Check if /dev/cec0 exists: ls -l /dev/cec0
Ensure cec-utils is installed
Try rebooting the Pi

Advanced Usage

You can integrate this script into your own automation:

# Turn on TV and switch to input 1
./cec-control.sh tv-on && sleep 2 && ./cec-control.sh input 1

# Use in cron jobs or other scripts
@reboot /path/to/cec-control.sh tv-on

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