ESPHome Native HDMI-CEC Component

Make your ESPHome devices speak the (machine) language of your living room with this native HDMI-CEC (Consumer Electronics Control) component!

Features

• Native CEC 1.3a implementation
  • Implemented from scratch specifically for this component. No third-party CEC library used.
  • Meant to be as simple, lightweight and easy-to-understand as possible
  • Interrupts-based receiver (no polling at all). Handles low-level byte acknowledgements
• Receive CEC commands
  • Handle incoming messages with on_message triggers
    • Each trigger specified in on_message supports filtering based on source, destination, opcode and/or message contents
  • Built-in handlers for some of the system commands defined in the spec :
    • "Get CEC Version"
    • "Give Device Power Status"
    • "Give OSD Name"
• Send CEC commands
  • Built-in hdmi_cec.send action

To-do list

• Automatic Physical Address Discovery through E-DDC

Installation

1. Wire your ESPhome device to an HDMI connector (e.g. an HDMI breakout that can be found on Amazon) as follows :

   • GPIO pin of your choice -> HDMI pin 13 (CEC)
   • GND -> HDMI pin 17 (DDC/CEC ground)
   • Optional: wire your board's 5V supply to HDMI pin 18. This is how your TV/switch on the other end knows something is connected.

   The CEC bus uses 3.3V logic, so it's perfectly safe for ESP32/ESP8266 devices (or any other microcontroller with 3.3V logic).

2. In your ESPhome configuration file, add this Git repository as an external component

external_components:
  - source: github://Palakis/esphome-hdmi-cec

3. Setup the HDMI-CEC component

hdmi_cec:
  # Pick a GPIO pin that can do both input AND output
  pin: GPIO26 # Required
  # The address can be anything you want. Use 0xF if you only want to listen to the bus and not act like a standard device
  address: 0xE # Required
  # Physical address of the device. In this case: 4.0.0.0 (HDMI4 on the TV)
  # DDC support is not yet implemented, so you'll have to set this manually.
  physical_address: 0x4000 # Required
  # The name that will we displayed in the list of devices on your TV/receiver
  osd_name: "my device" # Optional. Defaults to "esphome"
  # By default, promiscuous mode is disabled, so the component only handles directly-address messages (matching
  # the address configured above) and broadcast messages. Enabling promiscuous mode will make the component
  # listen for all messages (both in logs and the on_message triggers)
  promiscuous_mode: false # Optional. Defaults to false
  # By default, monitor mode is disabled, so the component can send messages and acknowledge incoming messages.
  # Enabling monitor mode lets the component act as a passive listener, disabling active manipulation of the CEC bus.
  monitor_mode: false # Optional. Defaults to false
  # List of triggers to handle specific commands. Each trigger has the following optional filter parameters:
  # - "source": match messages coming from the specified address
  # - "destination": match messages meant for the specified address
  # - "opcode": match messages bearing the specified opcode
  # - "data": exact-match on message content
  # Actions called from these triggers is called with "source", "destination" and "data" as parameters
  on_message:
    - opcode: 0x36 # opcode for "Standby"
      then:
        logger.log: "Got Standby command"
    
    # Respond to "Menu Request" (not required, example purposes only)
    - opcode: 0x8D
      then:
        hdmi_cec.send:
          # both "destination" and "data" are templatable
          destination: !lambda return source;
          data: [0x8E, 0x01] # 0x01 => "Menu Deactivated"

4. (optional) Use the hdmi_cec.send action in your ESPHome configuration

button:
  - platform: template
    name: "Turn everything off"
    on_press:
      hdmi_cec.send:
        # "source" can optionally be set, like if you want to spoof another device's address
        destination: 0xF # Broadcast
        data: [0x36] # "Standby" opcode

5. (optional) Add Services for HomeAssistant

api
  ...
  services:
    - service: hdmi_cec_send
      variables:
        cec_destination: int
        cec_data: int[]
      then:
        - hdmi_cec.send:
            destination: !lambda "return static_cast<unsigned char>(cec_destination);"
            data: !lambda "std::vector<unsigned char> charVector; for (int i : cec_data) { charVector.push_back(static_cast<unsigned char>(i)); } return charVector;"

Compatibility

• ESP32: ✅ tested, works
• ESP8266: ✅ tested, works
• RP2040: ✅ tested, works
• LibreTiny: ❌ not supported
  • I don't have any LibreTiny device at hand. Feel free to run your own tests and report back your findings.

Acknowledgements

• johnboiles' esphome-hdmi-cec component has been the inspiration and starting point of this project.