Custom use of iOS Bluetooth button

[merri-ment]

你好!,

Greetings from New Zealand, I am hoping you can assist me.
I am developing an iOS Application that requires a remote bluetooth button.

I purchased this bluetooth button from Temu;
https://www.temu.com/goods.html?_bg_fs=1&goods_id=601099537315419

I inspected the bluetooth device and found a link to your company.
The Application i am developing uses Swift to connect to the bluetooth button, name "ATG-SJL".
I can pair successfully with it, but i am struggling to capture pressed events from the device.

Is it possible to use your tech to communicate with custom Applications?
or just the native iOS Camera application?

After i pair the bluetooth button, i see the native Volume UI appear and disappear.
Is iOS intercepting the keypress events on a lower level and routing them somewhere else?

Here is my swift code, "processInputReport" is never logged to the xcode console upon button press.

import Foundation
import Capacitor
import CoreBluetooth

@objc(BluetoothButtonPlugin)
public class BluetoothButtonPlugin: CAPPlugin, CBCentralManagerDelegate, CBPeripheralDelegate {
private var centralManager: CBCentralManager!
private var connectedPeripheral: CBPeripheral?
private let deviceName = "ATG-SJL"
private let deviceUUID = "9303D0FF-69DE-0137-0F69-EA4BC58D46C0"
private var ae42Characteristic: CBCharacteristic?
private var ae41Characteristic: CBCharacteristic? // Added AE41 characteristic
private var inputBuffer: [Data] = []
private var readTimer: Timer?

override public func load() {
    centralManager = CBCentralManager(delegate: self, queue: nil)
    print("BluetoothButtonPlugin loaded")
}

@objc func connect(_ call: CAPPluginCall) {
    print("Attempting to connect to ATG-SJL")
    if centralManager.state == .poweredOn {
        centralManager.scanForPeripherals(withServices: nil, options: nil)
        call.resolve()
    } else {
        call.reject("Bluetooth is not powered on")
    }
}

public func centralManagerDidUpdateState(_ central: CBCentralManager) {
    print("Bluetooth state updated: \(central.state.rawValue)")
    if central.state == .poweredOn {
        notifyListeners("bluetoothReady", data: nil)
        centralManager.scanForPeripherals(withServices: nil, options: nil)
    }
}

public func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
    print("Discovered peripheral: \(peripheral.name ?? "Unknown"), ID: \(peripheral.identifier.uuidString)")
    
    if peripheral.name == deviceName || peripheral.identifier.uuidString == deviceUUID {
        print("Found ATG-SJL device")
        connectedPeripheral = peripheral
        centralManager.stopScan()
        centralManager.connect(peripheral, options: nil)
    }
}

public func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
    print("Connected to device: \(peripheral.name ?? "Unknown")")
    peripheral.delegate = self
    peripheral.discoverServices(nil)
    notifyListeners("deviceConnected", data: ["name": peripheral.name ?? ""])
}

public func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
    guard let services = peripheral.services else { return }
    print("Discovered \(services.count) services")
    for service in services {
        print("Service: \(service.uuid)")
        peripheral.discoverCharacteristics(nil, for: service)
    }
}

public func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
    guard let characteristics = service.characteristics else { return }
    print("Discovered \(characteristics.count) characteristics for service: \(service.uuid)")
    
    for characteristic in characteristics {
        print("Characteristic: \(characteristic.uuid), Properties: \(characteristic.properties.rawValue)")
        
        if characteristic.uuid.uuidString == "AE42" {
            ae42Characteristic = characteristic
            peripheral.setNotifyValue(true, for: characteristic)
            print("Notifications enabled for AE42 characteristic")
        }
        
        if characteristic.uuid.uuidString == "AE41" {
            ae41Characteristic = characteristic
            peripheral.setNotifyValue(true, for: characteristic) // Enable notifications for AE41
            print("Notifications enabled for AE41 characteristic")
        }
    }
}

public func peripheral(_ peripheral: CBPeripheral, didUpdateNotificationStateFor characteristic: CBCharacteristic, error: Error?) {
    if let error = error {
        print("Error changing notification state for \(characteristic.uuid): \(error.localizedDescription)")
    } else {
        print("Notification state updated for characteristic: \(characteristic.uuid), isNotifying: \(characteristic.isNotifying)")
    }
}

public func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
    if let error = error {
        print("Error updating value for characteristic \(characteristic.uuid): \(error.localizedDescription)")
        return
    }
    
    guard let value = characteristic.value else {
        print("No value received for characteristic \(characteristic.uuid)")
        return
    }
    
    print("Value received for characteristic: \(characteristic.uuid), value: \(value.hexEncodedString())")
    
    if characteristic.uuid.uuidString == "AE42" {
        processInputReport(value)
    }
    
    if characteristic.uuid.uuidString == "AE41" {
        print("Value received for AE41: \(value.hexEncodedString())") // Log AE41 data
    }
}

private func processInputReport(_ data: Data) {
    print("Processing input report: \(data.hexEncodedString())")
    
    inputBuffer.append(data)
    
    print("Input buffer: \(inputBuffer.map { $0.hexEncodedString() })")
    
    // Check for button interactions like click, double click, long press
    if checkForSingleClick() {
        handleClick()
        inputBuffer.removeAll()
    } else if checkForDoubleClick() {
        handleDoubleClick()
        inputBuffer.removeAll()
    } else if checkForLongPress() {
        handleLongPress()
        inputBuffer.removeAll()
    }

    if inputBuffer.count > 20 {
        inputBuffer.removeAll()
    }
}

private func checkForSingleClick() -> Bool {
    let pattern: [UInt8] = [0x07, 0x06, 0x70, 0x07]
    return inputBuffer.contains { data in
        guard data.count >= pattern.count else { return false }
        return pattern.enumerated().allSatisfy { data[$0.offset] == $0.element }
    }
}

private func checkForDoubleClick() -> Bool {
    let pattern1: [UInt8] = [0x07, 0x07, 0x70, 0x07]
    let pattern2: [UInt8] = [0x00, 0x07, 0x70, 0x07]
    return inputBuffer.contains { data in
        guard data.count >= pattern1.count else { return false }
        return pattern1.enumerated().allSatisfy { data[$0.offset] == $0.element }
    } && inputBuffer.contains { data in
        guard data.count >= pattern2.count else { return false }
        return pattern2.enumerated().allSatisfy { data[$0.offset] == $0.element }
    }
}

private func checkForLongPress() -> Bool {
    let pressPattern: [UInt8] = [0x01, 0x00, 0x00]
    let releasePattern: [UInt8] = [0x00, 0x00, 0x00]
    return inputBuffer.contains { data in
        guard data.count >= pressPattern.count else { return false }
        return pressPattern.enumerated().allSatisfy { data[$0.offset] == $0.element }
    } && inputBuffer.contains { data in
        guard data.count >= releasePattern.count else { return false }
        return releasePattern.enumerated().allSatisfy { data[$0.offset] == $0.element }
    }
}

private func handleClick() {
    print("buttonSingleClick")
    notifyListeners("buttonSingleClick", data: [:])
}

private func handleDoubleClick() {
    print("buttonDoubleClick")
    notifyListeners("buttonDoubleClick", data: [:])
}

private func handleLongPress() {
    print("buttonLongPress")
    notifyListeners("buttonLongPress", data: [:])
}

@objc func disconnect(_ call: CAPPluginCall) {
    if let peripheral = connectedPeripheral {
        centralManager.cancelPeripheralConnection(peripheral)
        readTimer?.invalidate()
        call.resolve(["message": "Disconnected from ATG-SJL"])
    } else {
        call.reject("No device connected")
    }
}

@objc func isConnected(_ call: CAPPluginCall) {
    call.resolve(["connected": connectedPeripheral != nil])
}

}

extension Data {
func hexEncodedString() -> String {
return map { String(format: "%02hhx", $0) }.joined()
}
}

Here is my log;

Discovered peripheral: ATG-SJL, ID: 9303D0FF-69DE-0137-0F69-EA4BC58D46C0
Found ATG-SJL device
Connected to device: ATG-SJL
Discovered 3 services
Service: Device Information
Service: Battery
Service: AE40
Discovered 9 characteristics for service: Device Information
Characteristic: Manufacturer Name String, Properties: 2
Characteristic: Model Number String, Properties: 2
Characteristic: Serial Number String, Properties: 2
Characteristic: Hardware Revision String, Properties: 2
Characteristic: Firmware Revision String, Properties: 2
Characteristic: Software Revision String, Properties: 2
Characteristic: System ID, Properties: 2
Characteristic: IEEE Regulatory Certification, Properties: 2
Characteristic: PnP ID, Properties: 2
Discovered 1 characteristics for service: Battery
Characteristic: Battery Level, Properties: 18
Discovered 2 characteristics for service: AE40
Characteristic: AE41, Properties: 4
Notifications enabled for AE41 characteristic
Characteristic: AE42, Properties: 16
Notifications enabled for AE42 characteristic
Error changing notification state for AE41: The request is not supported.
Notification state updated for characteristic: AE42, isNotifying: true

Thanks in advance.

If you could supply any information,
it would be much appreciated!

[merri-ment]

Have created a Stackoverflow question;
https://stackoverflow.com/questions/79000668/issues-receiving-button-press-events-from-bluetooth-button-jieli-tech-atg-sjl