What is the difference between CoreBluetooth and ExternalAccessory wireframes?

Question

Apple provides the following two structures for communicating with neighboring Bluetooth devices with iOS.

CoreBluetooth:

The underlying Bluetooth infrastructure provides the classes required for iOS and Mac applications to communicate with devices equipped with low-power Bluetooth wireless technology.

ExternalAccessory:

The structure of the external accessory provides support for communication with external equipment connected to the iOS device via Apple Lightning or a 30-pin connector, or wirelessly using Bluetooth.

Earlier, I used the CoreBluetooth infrastructure to successfully communicate with Bluetooth devices. However, now I'm trying to establish a connection with a Bluetooth printer, and it does not appear when scanning neighboring devices. Using the ExternalAccessory structure, he does.

How do these two structures differ from each other in relation to communication with Bluetooth devices? Why do different bluetooth devices require different frameworks?

Answer 1

There are two types of Bluetooth, Bluetooth LE, which is very limited in bandwidth, but it does not require any user in the application settings and Bluetooth Classic, which requires the user to pair the device, but gives you more options and bandwidth, CoreBluetooth supports Bluetooth LE , and you can use it with a developer account. Bluetooth Classic requires you to join the Apple MFi program.

Answer 2

Core Bluetooth allows you to communicate with Bluetooth Low Energy devices using the GATT profile.

The structure of the external accessory allows you to communicate with "obsolete" Bluetooth devices using profiles such as the serial port protocol (SPP). To communicate with devices using the infrastructure of an external accessory, the device must be certified as part of the MFi program.

I also believe that in order to get an application that can communicate with your MFi device using an approved external accessory platform, the MFi licensee (i.e. printer provider) must provide some documents to authorize your application.