# This creates a sensor that detects if the TV is on, if the Chromecast is powered and pingable

binary_sensor: #goes in configuration.yaml
  - platform: ping
    count: 5
    scan_interval: 10
    name: chromecast_status
    host: your_chromecast_host

# In your switches.yaml file you can create a switch template. This one will show the TV as 'ON' if the Chromecast is found by the ping component

- platform: template
  switches:
    tv:
      friendly_name: TV
      value_template: "{{ is_state('binary_sensor.chromecast_status', 'on') }}"
      turn_on:
        service: script.turn_on
        entity_id: script.tv_on_script
      turn_off:
        service: script.turn_on
        entity_id: script.tv_off_script

# Now create the on and off scripts for the TV in scripts.yaml
# This 'on' script will only work if the TV is off, that way it won't accidently turn the TV off.
# The 'on' script uses my Roku to turn the TV on, while my 'off' script uses the Broadlink RM Pro to turn the TV off.
# You can adjust these depending on what hardware you have available.

tv_on_script:
  alias: TV On Script
  sequence:
    - condition: state
      entity_id: switch.tv
      state: 'off'
    - service: media_player.select_source
      data:
        entity_id: media_player.living_room
        source: Home

# This 'off' scripts will only work if the TV is on, that way I won't accidentally turn on a TV that's already off.

tv_off_script:
  alias: TV Off Script
  sequence:
    - condition: state
      entity_id: switch.tv
      state: 'on'
    - service: media_player.select_source
      data:
        entity_id: media_player.living_room
        source: Home
    - service: switch.broadlink_send_packet_192_168_0_4
      data:
        packet:
          - "JgBQAAABKZIUERQ1FDUUEBUQFRAVEBU0FTQVEBQ1FBEUERQRFBAVEBU0FTQVNBQ1FBEUERQRFBAVEBUQFRAVEBU0FTQUNRQ1FAAFigABKUcVAA0FAAAAAAAAAAA"