It works on android but not on ios

[muriloventuroso]

I'm using this plugin to print receipts on a thermal printer. On Android it works correctly. But not on iOS. The printer is detected and connected, but it gives an error when printing.
I tested the sample code and it also fails to print.

[VERBOSE-2:ui_dart_state.cc(198)] Unhandled Exception: PlatformException(FLUETOOTH_ERROR, The device does not support receiving bytes!, null, null)
#0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
#1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:167:18)
<asynchronous suspension>
#2      _MyAppState._print (package:fluetooth_example/main.dart:142:5)
<asynchronous suspension>

flutter doctor -v
[✓] Flutter (Channel stable, 3.0.5, on macOS 12.5 21G72 darwin-x64, locale en-US)
    • Flutter version 3.0.5 at /Users/muriloventuroso/Downloads/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision f1875d570e (9 days ago), 2022-07-13 11:24:16 -0700
    • Engine revision e85ea0e79c
    • Dart version 2.17.6
    • DevTools version 2.12.2

[✗] Android toolchain - develop for Android devices
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.dev/docs/get-started/install/macos#android-setup for detailed instructions).
      If the Android SDK has been installed to a custom location, please use
      `flutter config --android-sdk` to update to that location.


[✓] Xcode - develop for iOS and macOS (Xcode 13.4.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.3

[✗] Chrome - develop for the web (Cannot find Chrome executable at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[!] Android Studio (not installed)
    • Android Studio not found; download from https://developer.android.com/studio/index.html
      (or visit https://flutter.dev/docs/get-started/install/macos#android-setup for detailed instructions).

[✓] VS Code (version 1.69.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension can be installed from:
      🔨 https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[✓] Connected device (2 available)
    • iPhone (mobile) • 00008030-001C211411E8802E • ios        • iOS 15.5 19F77
    • macOS (desktop) • macos                     • darwin-x64 • macOS 12.5 21G72 darwin-x64

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 2 categories.

[iandis]

Hi @muriloventuroso thank you for submitting the issue.

Unfortunately, I couldn't manage to reproduce it on iOS. However, the issue might be because I made the library to only look for devices having .writeWithoutResponse characteristics. So if you wouldn't mind, please try this branch I just pushed that might fix this issue.

[muriloventuroso]

Unfortunately it didn't work. Same error. Apparently the device does not have the .writeWithoutResponse or .write characteristics.

I installed the POS-Printer app on ios and it works correctly.