fix some issues with authentication and bonding

Example/xDripG5/AppDelegate.swift

@@ -54,7 +54,9 @@ class AppDelegate: UIResponder, UIApplicationDelegate, TransmitterDelegate {
     func applicationDidBecomeActive(_ application: UIApplication) {
         // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
 
-        transmitter?.resumeScanning()
+        if let transmitter = transmitter , !transmitter.stayConnected {
+            transmitter.resumeScanning()
+        }
     }
 
     func applicationWillTerminate(_ application: UIApplication) {

xDripG5/BluetoothManager.swift

@@ -106,7 +106,7 @@ class BluetoothManager: NSObject {
         #endif
 
         if let peripheralID = self.peripheral?.identifier, let peripheral = manager.retrievePeripherals(withIdentifiers: [peripheralID]).first {
-            log.info("Re-connecting to known peripheral %{public}@ in %zds", peripheral.identifier.uuidString, delay)
+            log.info("Re-connecting to known peripheral %{public}@ in %.1f s", peripheral.identifier.uuidString, delay)
             self.peripheral = peripheral
             self.manager.connect(peripheral, options: connectOptions)
         } else if let peripheral = manager.retrieveConnectedPeripherals(withServices: [

xDripG5/PeripheralManager+G5.swift

@@ -65,12 +65,14 @@ extension PeripheralManager {
             peripheral.writeValue(value, for: characteristic, type: type)
         }
 
-        guard let value = characteristic.value else {
+        let value = characteristic.value
+
+        guard !characteristic.isNotifying || value != nil else {
             // TODO: This is an "unknown value" issue, not a timeout
             throw PeripheralManagerError.timeout
         }
 
-        return value
+        return value ?? Data()
     }
 }
 

xDripG5/Transmitter.swift

@@ -247,27 +247,17 @@ fileprivate extension PeripheralManager {
             throw TransmitterError.authenticationError("Error writing keep-alive for bond: \(error)")
         }
 
-        let data: Data
         do {
-            // Wait for the OS dialog to pop-up before continuing.
             _ = try writeValue(BondRequestTxMessage().data, for: .authentication)
-            data = try readValue(for: .authentication, timeout: 15, expectingFirstByte: AuthStatusRxMessage.opcode)
         } catch let error {
             throw TransmitterError.authenticationError("Error writing bond request: \(error)")
         }
-
-        guard let response = AuthStatusRxMessage(data: data) else {
-            throw TransmitterError.authenticationError("Unable to parse auth status: \(data)")
-        }
-
-        guard response.bonded == 0x1 else {
-            throw TransmitterError.authenticationError("Transmitter failed to bond")
-        }
     }
 
     func control() throws -> Glucose {
         do {
-            try setNotifyValue(true, for: .control)
+            // Wait for up to 15s for the user to respond to the pairing request.
+            try setNotifyValue(true, for: .control, timeout: 15)
         } catch let error {
             throw TransmitterError.controlError("Error enabling notification: \(error)")
         }