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beethowen_transmitter.rst

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Beethowen Transmitter

Beethowen is an energy efficient method to transfer data over ESP-NOW <https://www.espressif.com/en/solutions/low-power-solutions/esp-now> Wireless Communication Protocol by Espressif Systems between two devices. The name came from a playful 2 am brainstorming from "BTHome" + "Over" + "Esp-NoW".

This component implements local trasmitter and encoding hub that can be used both on ESP8266 and ESP32 devices.

ESP-NOW
is a wireless communication protocol defined by Espressif, which enables the direct, quick and low-power control of smart devices, without the need of a router. ESP-NOW can work with Wi-Fi and Bluetooth LE, and supports the ESP8266, ESP32, ESP32-S and ESP32-C series of SoCs. It’s widely used in smart-home appliances, remote controlling, sensors, etc.
BTHome
is an energy efficient but flexible format for devices to broadcast their sensor data and button presses originally developed for BLE (Bluetooth Low Energy) devices. Devices can run over a year on a single battery. It allows data encryption and is supported by popular home automation platforms, like Home Assistant, out of the box.
# Example configuration entry
external_components:
  - source: github://afarago/esphome_component_bthome

esphome:
  name: $systemName
  on_loop:
    - component.update: my_bmp085

beethowen_transmitter:
  id: my_beethowen_transmitter
  connect_persistent: true
  sensors:
    - measurement_type: temperature
      sensor_id: bmp085_temperature_sensor
    - measurement_type: pressure
      sensor_id: bmp085_pressure_sensor
  auto_send: true
  on_send_finished:
    - lambda: |-
        ESP_LOGD("app", "on_send_finished lambda");
        id(my_deep_sleep).begin_sleep(true);

sensor:
  - platform: bmp085
    id: my_bmp085
    temperature:
      id: bmp085_temperature_sensor
    pressure:
      id: bmp085_pressure_sensor

deep_sleep:
  run_duration: 20s # max run duration for safeguarding
  sleep_duration: 60s
  id: my_deep_sleep

Component/Hub

The beethowen_transmitter component creates a global hub so that you can collect beethowen sensor data from you ESP node and send them to Beethowen receiver remote node.

The beethowen transmitter hub component is an internal model that acts as a central collection hub to which beethowen transmitter sensors are connected to.

The component depends on the standard WiFi library e.g. ESP8266WiFi that needs to be added to the configuration. As for now the wifi component usage is untested and should be avoided.

Auto-find server

The beethowen_transmitter automatically checks each channel to find a node with a beethowen_receiver on the vicinity.

Note: some form of authentication or code-matching will be added soon.

Configuration variables:

  • id (Optional, string): Manually specify the ID for this Hub.
  • connect_persistent (Optional, boolean): ESP8266 is able to reconnect to the last used Wi-Fi network or establishes the same Access Point upon power up or reset. By default, these settings are NOT written to specific sectors of flash memory every time they are changed. Frequently calling these functions could cause wear on the flash memory. See WiFi library reference.
  • sensors (Optional): Specify sensors to proxy through the beethowen channel. See :ref:`beethowen-sensor` for more information.
  • auto_send (Optional, boolean): Regularly check all connected sensors and once all provide a valid state automatically send data.
  • local_passkey (Optional, int, 16-bit): Local passkey that serves as an identification or authorization of the node.
  • expected_remote_passkey (Optional, int, 16-bit): Remote passkey that identifies or authorizes the incoming communication packet.
  • restore_from_flash (Optional, boolean): Whether to store teh server data and channel as persistent preferences in flash memory. Defaults to true.

Automations

  • on_send_finished (Optional, Automation): An automation to perform when a transmission is finished.
  • on_send_failed (Optional, Automation): An automation to perform when a transmission is failed.

Authorization with a premature security concept:

As ESP-NOW is a a highly insecure channel it is not recommended to use it for purposes above sensing and broacasting. Opposed to the BLE broadcast mechanism I have implemented a handshake in which remote client send directed data to preidentified servers.

An optional handshake mechanism is easing this process where each node owns a local passkey that is included in the ransmission and checked on the recepient side. Proposed scenario is as follows:

  • beethowen_transmitter client is looking for a server with find_server message using its local passkey of 0x1234
  • beethowen_receiver server receives the command, validates the passkey against the expected passkey and answers only if it matches the passkey specified for the selected mac_address client
  • beethowen_receiver server answers with a server found response with its local passkey of 0x4567
  • beethowen_transmitter client receives the command, validates the passkey against the expected passkey and answers only if it matches the passkey specified. As it matches it accepts the server as the valid recepient for the sensing data.
  • beethowen_transmitter client sends sensor data using its local passkey of 0x1234
  • beethowen_receiver server receives the sensor data, validates the passkey against the expected passkey and accepts only if it matches the passkey specified for the selected mac_address client. As it matches it accepts the sensor data as the valid recepient for the sensing data.

Sensor

The beethowen transmitter sensor allows you use a sensor to collect and transfer data to a remote Beethowen receiver hub and are listed below the hub.

The beethowen sensor component acts as a proxy sensor that receives data from other pyhsical sensors.

beethowen_transmitter:
  sensors:
    - measurement_type: temperature
      sensor_id: bmp085_temperature_sensor
    - measurement_type: pressure
      sensor_id: bmp085_pressure_sensor

Configuration variables:

  • measurement_type (Required, int or string): Measurement type as defined in BTHome format specification either as a string or a numeric value.

    Measurement type further details to be taken into account.

  • sensor_id (Required, string): A sensor that is defined in the configuration. Its value will be retrieved and proxied through the beethowen channel.

Sensor Automation

on_send_finished

This automation will be triggered when a transmission is finished though the beethowen channel. In Lambdas you can get the result and check if there are any outstanding measurements not yet transferred with has_outstanding_measurements.

on_send_failed

This automation will be triggered when a transmission is failed though the beethowen channel.

Actions

send

This action collects all connected sensor data and sends them thorugh the beethowen channel.

script:
  then:
    - beethowen_transmitter.send_data
    - beethowen_transmitter.send_data: true
    - beethowen_transmitter.send_data:
        complete_only: true

Configuration variables:

The action can used with parameters or with data value of complete_only such as true or false.

  • complete_only (Optional, bool): Whether to send any available measurements or start sending only if all sensors have valid measurements. Defaults to true.

send_event

This action sends an event through the channel with queuing until successful transmission.

binary_sensor:
  - id: user_button
    on_click:
      - beethowen_transmitter.send_event: button_click
      - beethowen_transmitter.send_event:
          device_type: button
          event_type: double_click
      - beethowen_transmitter.send_event:
          device_type: dimmer
          event_type: left
          value: 3

Configuration variables:

The action can used with parameters or with data value of device_event_type such as button_click.

  • device_type (string): Device type id of the event.
  • event_type (string): Event type id of the event.
  • value (Optional, int): Value associated with the event (e.g. for dimmer)

See Also