[REQUEST] Add support for "hosted OpenThread" (ESP32 Hosted supporting Thread protocol)? (EHM-113)

[Hedda]

Checklist

• Checked the issue tracker for similar issues to ensure this is not a duplicate.
• Described the feature in detail and justified the reason for the request.
• Provided specific use cases and examples.

Feature description

Please consider adding support for hosted OpenThread (hosted Thread protocol) on chips like ESP32-S3 and ESP32-P4 which do not have an embedded Thread radio like ESP32-H2, ESP32-C6, and ESP32-C5 has.

• https://github.com/espressif/openthread

If this solution could be extended to also support Thread (OpenThread) it be even greater as it would enable OpenThread/Thread communication capabilities on the primary ESP32 without it having native Thread radio (e.g. ESP32-P4 and ESP32-S3).

Use cases

Extending this support to OpenThread (Thread) would allow the main host chip that do not have a radio for OpenThread to communicate over a Thread network mesh using IPv6 using a secondary/external SPI-connected ESP32-module that does have a Thread radio.

• https://github.com/espressif/openthread

ESP32 Hosted (ESP-Hosted-MCU) is a solution that allows you to use a ESP32 modules as a communication co-processors to provide wireless connectivity for the main ESP32 host module via a second ESP32 chip (with currenly Wi-Fi and Bluetooth being supported).

Alternatives

Development could be for example tested on Espressif's ESP Thread Border Router SDK hardware (based on ESP32-S3 and ESP32-H2), or anpther example setup would be combining the ESP32 DevKitC with the ESP32-H2 DevKitC (connect via UART):

• https://github.com/espressif/esp-thread-br

• https://github.com/espressif/esp-idf/tree/master/examples/openthread/ot_br

Additional context

Ping @SuGlider and @P-R-O-C-H-Y to ask for integration into arduino-esp32 as well https://github.com/espressif/arduino-esp32

PS: Also see downstream feature request which requests that this feature be implemented into ESPHome after added upstream:

• https://github.com/orgs/esphome/discussions/3356