At the heart of the “Walter” board lies the ESP32-S3 microcontroller, equipped with 2MB of RAM and 16MB of flash memory.

On the hardware front, you can use an old smartphone with a working mic and speaker to use the Home Assistant Companion app ...

In warmer climates, this may be more of an issue, but in Ireland, where I live, it's completely fine. I used ESPHome for this ...