Take an old Android phone you may already have lying around.
- Remove any SIM card
- Install VOIP softphone app and configure with WiFi.
- Go enjoy the $175 you didn't spend on this.
replies(2):
my old phone doesn't have:
20 pin programmable header on back of phone (including SPI, UART, I2C)
I2C Qwiic port (a lot of adafruit sensors have qwiic ports)
and code that i can modify in arduino ide
I guess there will be awesome niche applications for this phone that are supper useful to an audience of one person.