iOS write characteristic exception

[pbaker5]

On iOS, I able to successfully connect to a BLE device, but when I attempt to write to a characteristic I get the following exception. It works fine on Android. Any ideas?

[VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: BleException: The operation couldn’t be completed. (rx_ble.Errors error 1.)
0 plugin_scaffold 0x0000000100973e50 $s15plugin_scaffold14serializeErrorySo07FlutterD0CypF + 316
1 plugin_scaffold 0x0000000100975098 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctFyycfU_ + 312
2 plugin_scaffold 0x00000001009751d0 $sIeg_IeyB_TR + 52
3 plugin_scaffold 0x00000001009735d0 +[PluginScaffoldHelper tryCatch:onCatch:onElse:] + 108
4 plugin_scaffold 0x0000000100974f38 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctF + 624
5 plugin_scaffold 0x0000000100977828 $s15plugin_scaffold20createPluginScaffold9messenger11channelName9methodMapSo20FlutterMethodChannelCSo0K15BinaryMessenger_p_SSSDySSypGtFySo0kL4CallC_yypSgctcfU_yycfU_ + 4204
6 plugin_scaffold 0x0000000100974fd0 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctFyycfU_ + 112
7 plugin_scaffold 0x00000001009751d0 $sIeg_IeyB_TR + 52
8 plugin_scaffold 0x00000001009735d0 +[PluginScaffoldHelper tryCatch:onCatch:onElse:] + 108
9 plugin_scaffold 0x0000000100974f38 $s15plugin_scaffold11catchErrorsyyyypSgc_yyKctF + 624
10 plugin_scaffold 0x0000000100976730 $s15plugin_scaffold20createPluginScaffold9messenger11channelName9methodMapSo20FlutterMethodChannelCSo0K15BinaryMessenger_p_SSSDySSypGtFySo0kL4CallC_yypSgctcfU_ + 436
11 plugin_scaffold 0x000000010097a88c $sSo17FlutterMethodCallCypSgIegn_Ieggg_AByXlSgIeyBy_IeyByy_TR + 168
12 Flutter 0x0000000100adf2e8 __45-[FlutterMethodChannel setMethodCallHandler:]_block_invoke + 128
13 Flutter 0x0000000100a79f78 _ZNK7flutter21PlatformMessageRouter21HandlePlatformMessageEN3fml6RefPtrINS_15PlatformMessageEEE + 224
14 Flutter 0x0000000100a7e098 _ZN7flutter15PlatformViewIOS21HandlePlatformMessageEN3fml6RefPtrINS_15PlatformMessageEEE + 40
15 Flutter 0x0000000100ad9d4c _ZNSt3__110__function6__funcIZN7flutter5Shell29OnEngineHandlePlatformMessageEN3fml6RefPtrINS2_15PlatformMessageEEEE4$_27NS_9allocatorIS8_EEFvvEEclEv + 80
16 Flutter 0x0000000100a8b7c4 _ZN3fml15MessageLoopImpl10FlushTasksENS_9FlushTypeE + 116
17 Flutter 0x0000000100a901bc ZN3fml17MessageLoopDarwin11OnTimerFireEP16__CFRunLoopTimerPS0 + 32
18 CoreFoundation 0x00000001afdfa650 + 28
19 CoreFoundation 0x00000001afdfa380 + 864
20 CoreFoundation 0x00000001afdf9bb4 + 248
21 CoreFoundation 0x00000001afdf4b04 + 1844
22 CoreFoundation 0x00000001afdf40b0 CFRunLoopRunSpecific + 436
23 GraphicsServices 0x00000001b1ff479c GSEventRunModal + 104
24 UIKitCore 0x00000001dc39e978 UIApplicationMain + 212
25 Runner 0x000000010043bad4 main + 124
26 libdyld.dylib 0x00000001af8b98e0 + 4
#0 rethrowException
package:rx_ble/src/exception_serializer.dart:17
#1 RxBle.observeChar.
package:rx_ble/rx_ble.dart:260
#2 _invokeErrorHandler (dart:async/async_error.dart:17:29)
#3 _HandleErrorStream._handleError (dart:async/stream_pipe.dart:286:9)
#4 _ForwardingStreamSubscription._handleError (dart:async/stream_pipe.dart:168:13)
#5 _rootRunBinary (dart:async/zone.dart:1144:38)
#6 _CustomZone.runBinary (dart:async/zone.dart:1037:19)
#7 _CustomZone.runBinaryGuarded (dart:async/zone.dart:939:7)
#8 _BufferingStreamSubscription._sendError.sendError (dart:async/stream_impl.dart:355:15)
#9 _BufferingStreamSubscription._sendError (dart:async/stream_impl.dart:373:16)
#10 _BufferingStreamSubscription._addError (dart:async/stream_impl.dart:272:7)
#11 _ForwardingStreamSubscription._addError (dart:async/stream_pipe.dart:137:11)
#12 _ForwardingStream._handleError (dart:async/stream_pipe.dart:102:10)
#13 _ForwardingStreamSubscription._handleError (dart:async/stream_pipe.dart:168:13)
#14 _rootRunBinary (dart:async/zone.dart:1144:38)
#15 _CustomZone.runBinary (dart:async/zone.dart:1037:19)
#16 _CustomZone.runBinaryGuarded (dart:async/zone.dart:939:7)
#17 _BufferingStreamSubscription._sendError.sendError (dart:async/stream_impl.dart:355:15)
#18 _BufferingStreamSubscription._sendError (dart:async/stream_impl.dart:373:16)
#19 _DelayedError.perform (dart:async/stream_impl.dart:602:14)
#20 _StreamImplEvents.handleNext (dart:async/stream_impl.dart:707:11)
#21 _PendingEvents.schedule. (dart:async/stream_impl.dart:667:7)
#22 _rootRun (dart:async/zone.dart:1120:38)
#23 _CustomZone.run (dart:async/zone.dart:1021:19)
#24 _CustomZone.runGuarded (dart:async/zone.dart:923:7)
#25 _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:963:23)
#26 _rootRun (dart:async/zone.dart:1124:13)
#27 _CustomZone.run (dart:async/zone.dart:1021:19)
#28 _CustomZone.runGuarded (dart:async/zone.dart:923:7)
#29 _CustomZone.bindCallbackGuarded. (dart:async/zone.dart:963:23)
#30 _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#31 _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)

flutter doctor -v
[✓] Flutter (Channel stable, v1.7.8+hotfix.4, on Mac OS X 10.14.6 18G87, locale en-AU)
• Flutter version 1.7.8+hotfix.4 at /Users//Downloads/flutter
• Framework revision 20e59316b8 (4 weeks ago), 2019-07-18 20:04:33 -0700
• Engine revision fee001c93f
• Dart version 2.4.0

[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
• Android SDK at /Users//Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-28, build-tools 28.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b01)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 10.3)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 10.3, Build version 10G8
• CocoaPods version 1.7.4

[✓] iOS tools - develop for iOS devices
• ios-deploy 1.9.4

[✓] Android Studio (version 3.4)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 35.3.1
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• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1343-b01)

[✓] VS Code (version 1.37.0)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.3.0

[✓] Connected device (2 available)
• ’s iPad • 1949212cb39e1990bf4c654032f5e040b755efec • ios • iOS 12.3
• iPhone Xʀ • 99F72161-60A4-463B-8C03-901C15C46500 • ios • com.apple.CoreSimulator.SimRuntime.iOS-12-4 (simulator)

• No issues found!

[mengzhidaren]

writeChar to be change
sendSingle(peripheral.writeValue(value.data, for: char, type: .withoutResponse, canSendWriteWithoutResponseCheckEnabled: false), result) {
FlutterStandardTypedData(bytes: $0.value ?? Data())
}

to change withoutResponse not withResponse

[pbaker5]

@mengzhidaren thanks for the suggestion. I forked, made that change, but I got the same error.