Add Native Support for BTHomev v2 Protocol in ESPHome ( bthome / bthome_advertiser / bthome_advertisements)

[asucrews]

Describe the component you'd like

Currently, ESPHome can create BLE clients or trackers, and passively receive BTHome advertisements (e.g. from Xiaomi, Govee, or other sensors) using esp32_ble_tracker. However, there is no built-in component for advertising data using the BTHome protocol.

This enhancement would add a first-class bthome: component that:

Encodes sensor values into BTHome format

Optionally supports encryption using a shared key

Sends BTHome-compliant BLE advertisements periodically

This would allow ESP32 devices running ESPHome to act as BLE-only sensors, ideal for low-power, room presence, or air quality monitors — all interoperable with Home Assistant's native BTHome support.

What are your use cases for this component?

• Create BLE-only battery-powered ESPHome sensors (using ESP32-C3 or ESP32-H2)
• Avoid Wi-Fi to reduce power draw
• Interoperate with Home Assistant or any app supporting BTHome v2
• Enable ESPHome devices to participate in Open Home Foundation-compatible BLE ecosystems

Is there a public datasheet, documentation and/or schematics?

Spec:

• https://bthome.io/
• https://bthome.io/format/
• https://bthome.io/encryption/

Anything else?

• BTHome is developed by the same Open Home Foundation that stewards ESPHome and Home Assistant
• Spec: https://bthome.io/
• BTHome Python encoder (reference): https://github.com/basnijholt/bthome-ble
• Working ESP-IDF example (C-based encoder): https://github.com/atc1441/BTHome_ESP32
• Reference discussion on community interest: https://community.home-assistant.io/t/bthome-ble-esp32-transmitter-esphome/518773
• Could build on existing esp32_ble_advertising API or add a bthome: sensor platform for seamless YAML configuration
• Example(s) https://github.com/afarago/esphome_component_bthome