I recently played around with an Wemos D1 Mini Board and Mongoose OS. While there are tutorials out there that tell you how to get another firmware on such a device, I could not find myself any help on how to "revert" the device or switch back to "Arduino development".
So my questions are as follows: What is considered to be the "Arduino Firmware", how to get it and how to get it onto the board.
Thank you for your time,
yaespu