The full code of this project can be downloaded from https://www.packtpub.com/books/content/support.
To have a better understanding of the explanations in the next few paragraphs, open the downloaded code while reading.
Before going any further, we need to install the following additional libraries from Adafruit:
To install the libraries into the Arduino IDE, open the menu Sketch | Include Library | Manage Libraries …. For more information, see Chapter 2, Bluetooth Pet Door Locker.
Please refer to the downloaded code, since the setup code is quite simple and ...