Software & Setup Guide

This guide covers setting up Raspberry Pi OS (Bookworm 64-bit with Wayland / labWC), automating your television with HDMI-CEC, configuring audio output, and launching Google Meet in kiosk mode.

Step 1: Display & Kernel Configuration (Bookworm)

Edit /boot/firmware/cmdline.txt and /boot/firmware/config.txt to optimize display stability and route audio to HDMI.

1.1 Prevent labWC Crashes (Force HDMI Active)

To prevent labWC/Wayland from crashing when the TV is turned off, add the following parameter to the beginning of the line in /boot/firmware/cmdline.txt:

video=HDMI-A-1:1920x1200@60D

1.2 Disable 3.5mm Analog Audio (Force HDMI Audio Sink)

To prevent Raspberry Pi from routing audio to the 3.5mm AV headphone jack (snd_bcm2835), edit /boot/firmware/config.txt:

sudo nano /boot/firmware/config.txt

Add or update the following parameter under [all]:

dtparam=audio=off

Also disable CEC auto-init to prevent the TV from turning on upon system restart:

hdmi_ignore_cec_init=1

Step 2: Audio & Locale Configuration

1. System Locale: Set the default system locale to en_US.utf-8 using the configuration utility:

   sudo raspi-config
   

   Navigate to Localisation Options → Locale → en_US.UTF-8.

2. Select HDMI Audio Output:
   • Right-click the Sound/Speaker icon in the desktop top toolbar.
   • Under Device Profiles, set Audio Jack to Off. This instructs Wayland to use the connected HDMI display as the primary audio sink.
   • Select HDMI from the list of available audio output devices.
   • Right-click the Microphone icon to select your Logitech Brio webcam as the default input device.
3. Audio Driver (PipeWire vs PulseAudio):
   • Bookworm uses PipeWire by default. If your television speakers do not produce sound, open sudo raspi-config, go to Advanced Options → Audio Config, and switch the audio subsystem from PipeWire to PulseAudio.
4. Disable Screen Blanking:
   • In Raspberry Menu → Preferences → Raspberry Pi Configuration → Display, turn Screen Blanking to Disabled.

Step 3: Install HDMI-CEC & Wayland Input Utilities

Install cec-utils for TV control and wtype (the Wayland virtual keystroke tool that replaces X11’s xautomation):

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

Grant Non-Root Permissions for CEC

Create /etc/udev/rules.d/50-udev-default.rules so the pi user can access the CEC hardware bus:

echo 'KERNEL=="cec*", GROUP="pi", OWNER="pi"' | sudo tee -a /etc/udev/rules.d/50-udev-default.rules
sudo udevadm control --reload-rules && sudo udevadm trigger

Step 4: Create the TV Automation Script

Create /usr/local/bin/tv to control television power and input switching via simple terminal commands:

sudo nano /usr/local/bin/tv

Paste the following script:

#!/bin/bash
# /usr/local/bin/tv - HDMI-CEC Control Script for CallOnTV

case $1 in
  on)
    echo 'Waking TV from standby...'
    echo 'on 0' | cec-client -s -d 1
    ;;
  hdmi)
    echo 'Switching TV to Raspberry Pi HDMI input...'
    echo 'as' | cec-client -s -d 1
    ;;
  status)
    echo 'Checking TV power status...'
    echo 'pow 0' | cec-client -s -d 1
    ;;
  off)
    echo 'Putting TV in standby...'
    echo 'standby 0' | cec-client -s -d 1
    ;;
  scan)
    echo 'Scanning HDMI-CEC devices on the bus...'
    echo 'scan' | cec-client -s -d 1
    ;;
  *)
    echo "Usage: tv {on|hdmi|off|status|scan}"
    exit 1
    ;;
esac

Make the script executable:

sudo chmod +x /usr/local/bin/tv

Test Your TV Script

Verify CEC communication with your TV:

tv scan    # Verify communication with the TV CEC bus
tv on      # Powers on the television
tv hdmi    # Switches active video input to the Raspberry Pi
tv status  # Reports power status (standby vs on)
tv off     # Powers off the TV into standby mode

Step 5: Python Virtual Environment & Kiosk Autostart

Raspberry Pi OS Bookworm enforces PEP 668 managed Python environments. Create a dedicated virtual environment for automation scripts:

python3 -m venv /home/pi/python
/home/pi/python/bin/pip install pychrome requests

Chromium Kiosk Autostart

Configure Chromium to open your Google Meet room automatically on boot in kiosk mode:

Create ~/.config/autostart/callontv.desktop:

[Desktop Entry]
Type=Application
Name=CallOnTV
Exec=chromium-browser --noerrdialogs --disable-infobars --kiosk "https://meet.google.com/your-room-id"

For official Raspberry Pi kiosk tutorials, see the Raspberry Pi Kiosk Mode Documentation.

Step 6: Install CallOnTV Chrome Extension

To automate joining Google Meet calls without requiring a mouse, install the CallOnTV Chrome Extension (source available on GitHub).