We’ve actually already done most of the work for this item, but let’s see if there’s anything more we can do (at this point).
Remember that one of our current restrictions is to have no changes in the apps, themselves, so anything that we do has to be in the SDK-src directory. At this point, the Apps-src directory is still at the same version it was when we started (Tag itcb-09).
Everything that we’ve done, to this point, has been in the SDK.
This was a relatively short exercise, compared to the first series, and we made all of the changes inside the SDK-src directory.
Before we dive in, let’s take a bit of time to review how Core Bluetooth handles communications between Centrals and Peripherals.
As was noted in the previous series, the Peripheral is responsible for setting the values of Characteristics, and managing the lifetimes of Services.
The Central will have CBPeripheral, CBService, CBCharacteristic, and CBDescriptor instances, but they will all be read-only “proxies” of the CBPeripheralManager, CBMutableService, CBMutableCharacteristic, and CBMutableDescriptor instances managed by the Peripheral.
What’s nice, is that Core Bluetooth abstracts all the nitty-gritty of Bluetooth transport for us, and gives us a fairly manageable API.
One thing that we can do, is make sure that the Peripheral actually gets our question. Right now, we simply rely on the fact that we sent it to confirm its receipt.
We would like to wait until the Peripheral actually tells us that it received the question before we assume that it has been sent.
The goal of this exercise is to have the Peripheral (the “Magic 8-Ball” device) respond immediately, and completely randomly, to questions asked by the Central; without presenting a list of questions to the user of the Peripheral Mode app.
This series will pick up where the last series left off. It should be fairly quick, relatively.
If we do a recap of our conclusion, we were left with the following list of “TODOs”:
.writeWithoutResponse property set on the question, so we aren’t sure that the question made it to the Peripheral. We can ask the Peripheral to let us know if the question made it.We now have a complete, operational SDK and application.
This application demonstrates Bluetooth on all the current Apple platforms, from one codebase: Mac OS X, iPhone/iPod, iPad, Watch, and TV.
This codebase is compiled into four targets; native Swift-based frameworks that are focused on one (or more) of the above platforms. Currently, the functionality is as barely simple as possible. It just scratches the surface of Core Bluetooth, but does demonstrate a complete system, from a Peripheral, advertising Services, to a Central, scanning for Services, and connecting to Peripherals, in order to use those Services to communicate with the Peripheral.
At this point, the Peripheral is getting the question. Time to answer it.
In this entry, we’ll do a detailed code walkthrough of the changes that were made to get to this point.