Cara Terbaik: Buat Aplikasi Bluetooth Swift Dengan Perangkat Keras dalam 20 Menit

Di tutorial sebelumnya, Anda telah mempelajari cara menambahkan Bluetooth ke aplikasi Particle Xenon. Dengan begitu Anda dapat mengontrol LED RGB onboard dari aplikasi uji seperti nRF Connect atau Light Blue Explorer.

Dalam posting ini, kami akan mengambil satu langkah lebih jauh. Kami akan mengembangkan aplikasi Swift untuk mengontrol led Particle Mesh RGB. Jika semuanya berjalan dengan baik, Anda akan memiliki aplikasi yang berfungsi dalam waktu sekitar 20 menit!

Mari kita mulai.

Tidak punya waktu sekarang untuk membaca artikel lengkapnya?

Unduh versi PDF di sini.

Mempersiapkan

  • Instal Xcode. Anda dapat mengunduhnya dari App store di sini.
  • Anda juga memerlukan login Apple. Saya menggunakan email iCloud saya. Anda dapat membuat akun baru dalam Xcode jika Anda belum memilikinya.
  • Instal kode contoh RGB pada papan Particle Mesh.

Buat proyek

Setelah semuanya terinstal, mari kita ke hal-hal menyenangkan!

Buka Xcode dan buka File → New Project.

Proyek Baru Xcode

Pilih Aplikasi Single View.

Info Proyek Baru

Kemudian perbarui Nama Proyek sesuai keinginan Anda. Saya juga telah mengubah pengenal organisasi saya menjadi com.jaredwolff. Ubah sesuai keinginan Anda!

Pilih lokasi untuk menyimpannya.

Selanjutnya temukan Info.plist Anda .

Info.plist di Xcocde

Perbarui info.plistdengan menambahkanPrivacy - Bluetooth Peripheral Usage Description

Deskripsi yang akhirnya saya gunakan adalah App uses Bluetooth to connect to the Particle Xenon RGB Example

Ini memungkinkan Anda untuk menggunakan Bluetooth di aplikasi Anda jika Anda ingin merilisnya.

Sekarang, mari kita buat semuanya berfungsi minimal!

Berfungsi minimal

Gambar bagian baru

Selanjutnya, kita akan mendapatkan aplikasi yang berfungsi minimal untuk menghubungkan dan melakukan penemuan layanan. Sebagian besar aksi akan terjadi di ViewController.swift.

Mari impor pertama CoreBluetooth

 import CoreBluetooth 

Ini memungkinkan kami untuk mengontrol fungsionalitas Bluetooth Hemat Energi di iOS. Lalu, mari tambahkan the CBPeripheralDelegatedan CBCentralManagerDelegateke ViewControllerkelas.

 class ViewController: UIViewController, CBPeripheralDelegate, CBCentralManagerDelegate { 

Sekarang mari kita buat variabel privat lokal untuk menyimpan manajer pusat dan periferal aktual. Kami akan menyiapkannya lebih lanjut sebentar lagi.

 // Properties private var centralManager: CBCentralManager! private var peripheral: CBPeripheral! 

Dalam viewDidLoadfungsi Anda , mari kita masuk kecentralManager

 centralManager = CBCentralManager(delegate: self, queue: nil) 

Pengaturan delegate: selfitu penting. Jika tidak, negara bagian pusat tidak pernah berubah saat memulai.

Sebelum melangkah lebih jauh, mari buat file terpisah dan beri nama ParticlePeripheral.swift. Itu dapat ditempatkan di mana saja tetapi saya menempatkannya dalam 'grup' terpisah yang disebut Model untuk nanti.

Di dalamnya kita akan membuat beberapa variabel publik yang berisi UUID untuk Particle Board kita. Mereka seharusnya terlihat familiar!

 import UIKit import CoreBluetooth class ParticlePeripheral: NSObject { /// MARK: - Particle LED services and charcteristics Identifiers public static let particleLEDServiceUUID = CBUUID.init(string: "b4250400-fb4b-4746-b2b0-93f0e61122c6") public static let redLEDCharacteristicUUID = CBUUID.init(string: "b4250401-fb4b-4746-b2b0-93f0e61122c6") public static let greenLEDCharacteristicUUID = CBUUID.init(string: "b4250402-fb4b-4746-b2b0-93f0e61122c6") public static let blueLEDCharacteristicUUID = CBUUID.init(string: "b4250403-fb4b-4746-b2b0-93f0e61122c6") } 

Back in ViewController.swift let's piece together the Bluetooth bits.

Bluetooth bits

Diagram alir untuk Bluetooth Swift di iOS

Everything to do with Bluetooth is event based. We'll be defining several functions that handle these events. Here are the important ones:

centralManagerDidUpdateState updates when the Bluetooth Peripheral is switched on or off. It will fire when an app first starts so you know the state of Bluetooth. We also start scanning here.

The centralManagerdidDiscover event occurs when you receive scan results. We'll use this to start a connection.

The centralManagerdidConnect event fires once the device is connected. We'll start the device discovery here. Note: Device discovery is the way we determine what services and characteristics are available. This is a good way to confirm what type of device we're connected to.

The peripheraldidDiscoverServices event first once all the services have been discovered. Notice that we've switched from centralManager to peripheral now that we're connected. We'll start the characteristic discovery here. We'll be using the RGB service UUID as the target.

The peripheraldidDiscoverCharacteristicsFor event will provide all the characteristics using the provided service UUID. This is the last step in the chain of doing a full device discovery. It's hairy but it only has to be done once during the connection phase!

Defining all the Bluetooth functions.

Now that we know what the functions events that get triggered. We'll define them in the logical order that they happen during a connection cycle.

First, we'll define centralManagerDidUpdateState to start scanning for a device with our Particle RGB LED Service. If Bluetooth is not enabled, it will not do anything.

 // If we're powered on, start scanning func centralManagerDidUpdateState(_ central: CBCentralManager) { print("Central state update") if central.state != .poweredOn { print("Central is not powered on") } else { print("Central scanning for", ParticlePeripheral.particleLEDServiceUUID); centralManager.scanForPeripherals(withServices: [ParticlePeripheral.particleLEDServiceUUID], options: [CBCentralManagerScanOptionAllowDuplicatesKey : true]) } } 

Defining the centralManagerdidDiscover is our next step in the process. We know we've found a device if this event has occurred.

 // Handles the result of the scan func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) { // We've found it so stop scan self.centralManager.stopScan() // Copy the peripheral instance self.peripheral = peripheral self.peripheral.delegate = self // Connect! self.centralManager.connect(self.peripheral, options: nil) } 

So, we stop scanning using self.centralManager.stopScan(). We set the peripheral so it persists through the app. Then we connect to that device using self.centralManager.connect

Once connected, we need to double check if we're working with the right device.

 // The handler if we do connect succesfully func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) { if peripheral == self.peripheral { print("Connected to your Particle Board") peripheral.discoverServices([ParticlePeripheral.particleLEDServiceUUID]) } } 

By comparing the two peripherals we'll know its the device we found earlier. We'll kick off a services discovery using peripheral.discoverService. We can use ParticlePeripheral.particleLEDServiceUUID as a parameter. That way we don't pick up any services we don't care about.

Once we finish the discovering services, we'll get a didDiscoverServices event. We iterate through all the "available" services. (Though there will only be one!)

 // Handles discovery event func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) { if let services = peripheral.services { for service in services { if service.uuid == ParticlePeripheral.particleLEDServiceUUID { print("LED service found") //Now kick off discovery of characteristics peripheral.discoverCharacteristics([ParticlePeripheral.redLEDCharacteristicUUID, ParticlePeripheral.greenLEDCharacteristicUUID, ParticlePeripheral.blueLEDCharacteristicUUID], for: service) return } } } } 

By this point this is the third time we're checking to make sure we have the correct service. This becomes more handy later when there are many characteristics and many services.

We call peripheral.discoverCharacteristics with an array of UUIDs for the characteristics we're looking for. They're all the UUIDs that we defined in ParticlePeripheral.swift.

Finally, we handle the didDiscoverCharacteriscsFor event. We iterate through all the available characteristics. As we iterate we compare with the ones we're looking for.

 // Handling discovery of characteristics func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) { if let characteristics = service.characteristics { for characteristic in characteristics { if characteristic.uuid == ParticlePeripheral.redLEDCharacteristicUUID { print("Red LED characteristic found") } else if characteristic.uuid == ParticlePeripheral.greenLEDCharacteristicUUID { print("Green LED characteristic found") } else if characteristic.uuid == ParticlePeripheral.blueLEDCharacteristicUUID { print("Blue LED characteristic found"); } } } } 

At this point we're ready to do a full device discovery of our Particle Mesh device. In the next section we'll test what we have to make sure things are working ok.

Testing our minimal example

Gambar bagian tentang pengujian

Before we get started, if you run into trouble I've put some troubleshooting steps in the footnotes.

To test, you'll have to have an iPhone with Bluetooth Low Energy. Most modern iPhones have it. The last iPhone not to have it I believe was either the iPhone 4 or 3Gs. (so you're likely good)

First, plug it into your computer.

Go to the top by the play and stop buttons. Select your target device. In my case I chose my phone (Jared's iPhone). You can also use an iPad.

Pilih jenis perangkat

Then you can hit Command + R or hit that Play button to load the app to your phone.

Make sure you have your log tab open. Enable it by clicking the bottom pane button in the top right corner.

Panel bawah di Xcode untuk log

Make sure you have a mesh device setup and running the example code. You can go to this post to get it. Remember your Particle Mesh board needs to be running device OS 1.3.0 or greater for Bluetooth to work!

Once both the firmware and app is loaded, let's check the log output.

It should look something like this:

View loaded Central state update Central scanning for B4250400-FB4B-4746-B2B0-93F0E61122C6 Connected to your Particle Board LED service found Red LED characteristic found Green LED characteristic found Blue LED characteristic found 

This means that your Phone has connected, found the LED service! The characteristics also being discovered is important here. Without those we wouldn't be able to send data to the mesh device.

Next step is to create some sliders so we can update the RGB values on the fly.

Slide to the left. Slide to the right.

Next we're going to add some elements to our Main.storyboard. Open Main.storyboard and click on the View underneath View Controller.

Memperbarui tampilan di Xcode

Then click on the Library button. (It looks like the old art Apple used for the home button)

Library button in Xcode

You'll get a pop-up with all the choices that you can insert into your app.

Library pane in Xcode

Drag three Labels and copy three Sliders to your view.

Dragging Labels to Xcode View

You can double click on the labels and rename them as you go.

Dragging Slider to Xcode View

If you click and hold, some handy alignment tools will popup. They'll even snap to center!

Alignment tools in Xcode

You can also select them all and move them together. We'll align them vertically and horizontally.

In order for them to stay in the middle, let's remove the autoresizing property. Click the Ruler icon on the top right. Then click each of the red bars. This will ensure that your labels and sliders stay on the screen!

Ruler pane in Xcode

Next let's click the Show Assistant Editor button. (Looks like a Venn diagram)

Show Assistant Editor button in Xcode

Note: make sure that ViewController.swift is open in your Assistant Editor.

Automatic option in Assistant Editor

Then underneath the /properties section, Control-click and dragthe Red Slider into your code.

Drag slider to code

Repeat with all the other ones. Make sure you name them something different. Your code should look like this when you're done:

 // Properties private var centralManager: CBCentralManager! private var peripheral: CBPeripheral! // Sliders @IBOutlet weak var redSlider: UISlider! @IBOutlet weak var greenSlider: UISlider! @IBOutlet weak var blueSlider: UISlider! 

This allow us to access the value of the sliders.

Next, let's attach the Value Changed event to each of the sliders. Right click on the Red Slider in the folder view.

Drag value changed event to code

It should give you some options for events. Click and drag the Value Changed event to your code. Make sure you name it something that makes sense. I used RedSliderChanged for the Red Slider.

Repeat two more times. Your code should look like this at the end of this step:

 @IBAction func RedSliderChanged(_ sender: Any) { } @IBAction func GreenSliderChanged(_ sender: Any) { } @IBAction func BlueSliderChanged(_ sender: Any) { } 

I've also selected each of the sliders to and un-checked Enabled. That way you can't move them. We'll enable them later on in code.

Disable slider by default

Also, this is a great time to change the maximum value to 255. Also set the default value from 0.5 to 0.

Set default value and max value of slider

Back at the top of the file. Let's create some local variables for each of the characteristics. We'll use these so we can write the slider variables to the Particle Mesh board.

 // Characteristics private var redChar: CBCharacteristic? private var greenChar: CBCharacteristic? private var blueChar: CBCharacteristic? 

Now, let's tie everything together!

In the didDiscoverCharacteristicsFor callback function. Let's assign those characteristics. For example

 if characteristic.uuid == ParticlePeripheral.redLEDCharacteristicUUID { print("Red LED characteristic found") redChar = characteristic 

As we find each characteristic, we can also enable each of the sliders in the same spot.

 // Unmask red slider redSlider.isEnabled = true 

In the end your didDiscoverCharacteristicsFor should look like:

 // Handling discovery of characteristics func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) { if let characteristics = service.characteristics { for characteristic in characteristics { if characteristic.uuid == ParticlePeripheral.redLEDCharacteristicUUID { print("Red LED characteristic found") redChar = characteristic redSlider.isEnabled = true } else if characteristic.uuid == ParticlePeripheral.greenLEDCharacteristicUUID { print("Green LED characteristic found") greenChar = characteristic greenSlider.isEnabled = true } else if characteristic.uuid == ParticlePeripheral.blueLEDCharacteristicUUID { print("Blue LED characteristic found"); blueChar = characteristic blueSlider.isEnabled = true } } } } 

Now, let's update the RedSliderChangedGreenSliderChanged and BlueSliderChanged functions. What we want to do here is update the characteristic associated with the Changed function. I created a separate function called writeLEDValueToChar. We'll pass in the characteristic and the data.

 private func writeLEDValueToChar( withCharacteristic characteristic: CBCharacteristic, withValue value: Data) { // Check if it has the write property if characteristic.properties.contains(.writeWithoutResponse) && peripheral != nil { peripheral.writeValue(value, for: characteristic, type: .withoutResponse) } } 

Now add a call to writeLEDValueToChar to each of the Changed functions. You will have to cast the value to a Uint8. (The Particle Mesh device expects an unsigned 8-bit number.)

 @IBAction func RedSliderChanged(_ sender: Any) { print("red:",redSlider.value); let slider:UInt8 = UInt8(redSlider.value) writeLEDValueToChar( withCharacteristic: redChar!, withValue: Data([slider])) } 

Repeat this for GreenSliderChanged and BlueSliderChanged. Make sure you changed red to green and blue for each!

Finally, to keep things clean, i've also added a function that handles Bluetooth disconnects.

 func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) { 

Inside, we should reset the state of the sliders to 0 and disable them.

 if peripheral == self.peripheral { print("Disconnected") redSlider.isEnabled = false greenSlider.isEnabled = false blueSlider.isEnabled = false redSlider.value = 0 greenSlider.value = 0 blueSlider.value = 0 

It's a good idea to reset self.peripheral to nil that way we're not ever trying to write to a phantom device.

 self.peripheral = nil 

Finally, because we've disconnected, start scanning again!

 // Start scanning again print("Central scanning for", ParticlePeripheral.particleLEDServiceUUID); centralManager.scanForPeripherals(withServices: [ParticlePeripheral.particleLEDServiceUUID], options: [CBCentralManagerScanOptionAllowDuplicatesKey : true]) } 

Alright! We just about ready to test. Let's move on to the next (and final) step.

Test the sliders.

Next section test!

The hard work is done. Now it's time to play!

The easiest way to test everything is to click the Play button in the top left or the Command + R keyboard shortcut. Xcode will load the app to your phone. You should see a white screen proceeded by a screen with your sliders!

The sliders should stay greyed out until connected to your Particle Mesh board. You can check your log output if the connection has been established.

View loaded Central state update Central scanning for B4250400-FB4B-4746-B2B0-93F0E61122C6 Connected to your Particle Board LED service found Red LED characteristic found Green LED characteristic found Blue LED characteristic found 

(Look familiar? We're connected!)

If you followed everything perfectly, you should be able to move the sliders. Better yet, the RGB LED on the Particle Mesh board should change color.

Final test results

Conclusion

Pada artikel ini Anda telah mempelajari cara menghubungkan papan Particle Mesh dan perangkat iOS Anda melalui Bluetooth. Kami telah mempelajari cara menghubungkan ke setiap karakteristik yang tersedia. Selain itu, di atas semua itu, buat antarmuka yang bersih untuk melakukan semuanya.

Seperti yang dapat Anda bayangkan, Anda dapat menelusuri lubang kelinci dengan Bluetooth di iOS. Masih ada lagi yang akan datang dalam panduan saya yang akan datang: Panduan Utama untuk Particle Mesh. Pelanggan daftar saya mendapatkan akses ke konten pra-peluncuran dan diskon saat dirilis! Klik di sini untuk mendaftar.

Kode

Kode sumber lengkap tersedia di Github. Jika Anda merasa berguna, tekan tombol bintang. ⭐️