thon-ju / bluetooth_print Goto Github PK

在项目中引入xxx.a文件需要配置什么，怎么配置？我这边引到项目，然后在xcode上点击run就提示是没找到xxx.a文件

请问一下如何扫描蓝牙连接
谢谢

最近一直在关注这个项目，我也尝试用了一下，以后几点建议

1. 缺少画线的方法
2. 缺少画框的方法
3. 最好能直接发送打印指令

谢谢

how can i print to a printer on the usb port?

String text = "1234";

list.add(LineText(type: LineText.TYPE_BARCODE, content: text , size:10, align: LineText.ALIGN_CENTER, linefeed: 1));

Additional characters "{B" are prefixed to the barcode text after printing. Scanning the printed barcode still gives {B1234.

D/BluetoothPrintPlugin( 9980): start scan
D/BluetoothAdapter( 9980): STATE_ON
D/BluetoothLeScanner( 9980): onClientRegistered() - status=0 clientIf=6
I/flutter ( 9980): cur device status: 12
D/BluetoothAdapter( 9980): STATE_ON

repeating these lines while scanning

Is something wrong with my code? I am trying to print using this function and an error is occurring, leave the logcat below.

void connectDevice(BuildContext context,
      {void Function(BluetoothPrint) connected}) {
    _bluetooth.state.listen((state) {
      if (state == BluetoothPrint.CONNECTED) {
        _bluetooth.printReceipt(Map(), [
          LineText(
              type: LineText.TYPE_TEXT,
              size: 12,
              content: 'Ola mundo',
              align: LineText.ALIGN_CENTER,
              linefeed: 1)
        ]);
      }
    });
    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) {
        return AlertDialog(
          title: Text('Encontar dispositivos'),
          content: StreamBuilder<bool>(
            key: UniqueKey(),
            initialData: false,
            stream: _bluetooth.isScanning,
            builder: (_, status) {
              return Column(
                mainAxisSize: MainAxisSize.max,
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: <Widget>[
                  StreamBuilder<List<BluetoothDevice>>(
                    key: UniqueKey(),
                    initialData: [],
                    stream: _bluetooth.scanResults,
                    builder: (_, results) {
                      return results.data.length == 0 && status.data
                          ? Expanded(
                              child: Center(
                                child: CircularProgressIndicator(),
                              ),
                            )
                          : ListView(
                              key: UniqueKey(),
                              shrinkWrap: true,
                              children: results.data
                                  .map(
                                    (device) => ListTile(
                                      key: UniqueKey(),
                                      enabled: status.data ? false : true,
                                      title: Text('${device.name}'),
                                      subtitle: Text('${device.address}'),
                                      onTap: () {
                                        _bluetooth.connect(device);
                                      },
                                    ),
                                  )
                                  .toList(),
                            );
                    },
                  ),
                  FlatButton(
                    onPressed: () => status.data
                        ? _bluetooth.stopScan()
                        : _bluetooth.startScan(),
                    child: Text(status.data
                        ? 'ENCERRAR BUSCA'
                        : 'BUSCAR DISPOSITIOVOS'),
                  )
                ],
              );
            },
          ),
        );
      },
    );
  }

2020-01-17 16:54:30.657 24773-24925/juniojsv.bem_servir_comanda W/BluetoothAdapter: getBluetoothService() called with no BluetoothManagerCallback
2020-01-17 16:54:33.617 24773-24773/juniojsv.bem_servir_comanda D/BluetoothPrintPlugin: stateStreamHandler, current action: android.bluetooth.device.action.ACL_CONNECTED
2020-01-17 16:54:33.632 24773-24789/juniojsv.bem_servir_comanda E/flutter: [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(not connect, state not right, null)
    #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:569:7)
    #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:156:18)
    <asynchronous suspension>
    #2      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:329:12)
    #3      BluetoothPrint.printReceipt (package:bluetooth_print/bluetooth_print.dart:141:14)
    #4      AppModel.connectDevice.<anonymous closure> (package:bem_servir_comanda/models/app_model.dart:20:20)
    #5      _rootRunUnary (dart:async/zone.dart:1134:38)
    #6      _CustomZone.runUnary (dart:async/zone.dart:1031:19)
    #7      _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
    #8      _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:339:11)
    #9      _DelayedData.perform (dart:async/stream_impl.dart:594:14)
    #10     _StreamImplEvents.handleNext (dart:async/stream_impl.dart:710:11)
    #11     _PendingEvents.schedule.<anonymous closure> (dart:async/stream_impl.dart:670:7)
    #12     _rootRun (dart:async/zone.dart:1122:38)
    #13     _CustomZone.run (dart:async/zone.dart:1023:19)
    #14     _CustomZone.runGuarded (dart:async/zone.dart:925:7)
    #15     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:965:23)
    #16     _rootRun (dart:async/zone.dart:1126:13)
    #17     _CustomZone.run (dart:async/zone.dart:1023:19)
    #18     _CustomZone.runGuarded (dart:async/zone.dart:925:7)
    #19     _CustomZone.bindCallbackGuarded.<anonymous closure> (dart:async/zone.dart:965:23)
    #20     _microtaskLoop (dart:async/schedule_microtask.dart:43:21)
    #21     _startMicrotaskLoop (dart:async/schedule_microtask.dart:52:5)
2020-01-17 16:54:33.820 24773-24960/juniojsv.bem_servir_comanda E/DeviceConnFactoryManager: wait read 
2020-01-17 16:54:35.573 24773-24960/juniojsv.bem_servir_comanda E/BluetoothPort: read length1
2020-01-17 16:54:35.573 24773-24960/juniojsv.bem_servir_comanda E/DeviceConnFactoryManager:  read 1
2020-01-17 16:54:35.575 24773-24960/juniojsv.bem_servir_comanda E/DeviceConnFactoryManager: wait read 

I have resized the image and changed the width. It still does not print Image in full.

list.add(
LineText(
width: 20,
type: LineText.TYPE_IMAGE,
content: base64Image,
align: LineText.ALIGN_CENTER,
linefeed: 1
)
);

i have been using this plugin for more than 6 month now without an issue but after adding new futures to my app like backgroundtask with workmanager and noftications with flutter_local_notfication will cause
Tried to automatically register plugins with FlutterEngine (io.flutter.embedding.engine.FlutterEngine@c154952) but could not find and invoke the GeneratedPluginRegistrant.
removing bluetooth_print from yaml file will make things works perfectly

C:\flutter\.pub-cache\hosted\pub.dartlang.org\bluetooth_print-2.0.0\android\src\main\java\com\example\bluetooth_print\BluetoothPrintPlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.

this plugin is the only one within the flutter community that serves my app needs (it can even be a paid task)

我阅读了一下你的插件源码，发现在android的源码里面，PrintContent.java 中的mapToReceipt函数有以下实现，
//打印走纸n个单位
esc.addPrintAndFeedLines((byte) 4);

// 开钱箱
esc.addGeneratePlus(LabelCommand.FOOT.F2, (byte) 255, (byte) 255);
//开启切刀
esc.addCutPaper();
//添加缓冲区打印完成查询
byte [] bytes={0x1D,0x72,0x01};
//添加用户指令
esc.addUserCommand(bytes);

但是在ios里面，BluetoothPrintPlugin.m中的mapToEscCommand函数里，只有以下实现
[command addPrintAndFeedLines:4];
return [command getCommand];

是不是因为ios中没有实现开启切刀，所以才导致ios打印完小票后，无法切纸的问题呢？

If phone is connecting a printer using other app or via phone bluetooth setting, we need show device is connected. I can't find a api, should be a feature request?

搜索不到蓝牙打印设备

Hi Guys, i just download the package, but the method bluetoothPrint.startScan(timeout: Duration(seconds: 4)); it's not available.
How to proceed?

I tried this package with 2 devices,

Device 1. I've tried scan bluetooth device in android 10 device (Redmi Note 9 : Bluetooth version is 5.0), but callback give me nothing.

Device 2. and then I've tried in android 9 device (Realme C2 : Bluetooth version is 4.2), while scanning for devices managed to get a list of devices including the printer. but I can't connect to the printer I want and terminal shows me like below :

D/BluetoothSocket(28482): close() this: android.bluetooth.BluetoothSocket@1a1c51a, channel: 2, mSocketIS: android.net.LocalSocketImpl$SocketInputStream@80b084b, mSocketOS: android.net.LocalSocketImpl$SocketOutputStream@e3b9228mSocket: null, mSocketState: CLOSED
D/BluetoothSocket(28482): close() this: android.bluetooth.BluetoothSocket@1a1c51a, channel: 2, mSocketIS: android.net.LocalSocketImpl$SocketInputStream@80b084b, mSocketOS: android.net.LocalSocketImpl$SocketOutputStream@e3b9228mSocket: null, mSocketState: CLOSED
W/System.err(28482): java.io.IOException: bt socket closed, read return: -1
W/System.err(28482): 	at android.bluetooth.BluetoothSocket.read(BluetoothSocket.java:558)
W/System.err(28482): 	at android.bluetooth.BluetoothInputStream.read(BluetoothInputStream.java:88)
W/System.err(28482): 	at java.io.InputStream.read(InputStream.java:101)
W/System.err(28482): 	at com.gprinter.io.BluetoothPort.readData(BluetoothPort.java:130)
W/System.err(28482): 	at com.example.bluetooth_print.DeviceConnFactoryManager.readDataImmediately(DeviceConnFactoryManager.java:416)
W/System.err(28482): 	at com.example.bluetooth_print.DeviceConnFactoryManager$PrinterReader.run(DeviceConnFactoryManager.java:496)
E/BluetoothPort(28482): connection device is lost
E/DeviceConnFactoryManager(28482):  read 0
D/BluetoothPrintPlugin(28482): stateStreamHandler, current action: android.bluetooth.device.action.ACL_DISCONNECTED
I/flutter (28482): cur device status: 0

*Printer
XPrinter BP-428U

比如 rxdart: ">=0.24.0"
否则与其他库冲突（比如说month_picker_dialog 0.3.2)

我基于flutter:1.22.4 ，bluetooth_print：2.0.0，做蓝牙打印机测试，在ios端，打印完小票之后，打印机无法自动切纸，android端可以正常切纸。测试过2款打印机，都有这个问题，机器分别是,GP-L80160I,BTP-X66
另外，华为P30 pro上面运行的时候，无法搜索到蓝牙打印机设备。

What is the license for this library? can i suggest MIT?

Ho To Fix This Error
E/BluetoothPort(29198): connection device is lost
E/DeviceConnFactoryManager(29198): read 0
D/BluetoothPrintPlugin(29198): stateStreamHandler, current action: android.bluetooth.device.action.ACL_DISCONNECTED

ios can't cut paper, can this problem be solved?

我用的資江 8003型號（ZJ-8003)
http://www.zjiang.com/en/init.php/product/index?id=33

用了IOS PRINTSDK，項目加了libPrinterSDK.a (資江驅動下載)

能找到列印機，但是按那三個打印測試都沒反應

--

Hello,

I can not build your example,

I got this error:

C:\Users\bekir.oruc\AndroidStudioProjects\nuqud_mobile\android\app\src\debug\AndroidManifest.xml Error:
uses-sdk:minSdkVersion 16 cannot be smaller than version 21 declared in library [:bluetooth_print] C:\Users\bekir.oruc\AndroidStudioProjects\nuqud_mobile\build\bluetooth_print\intermediates\library_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 16
Suggestion: use a compatible library with a minSdk of at most 16,
or increase this project's minSdk version to at least 21,
or use tools:overrideLibrary="com.example.bluetooth_print" to force usage (may lead to runtime failures)

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':app:processDebugManifest'.

Manifest merger failed : uses-sdk:minSdkVersion 16 cannot be smaller than version 21 declared in library [:bluetooth_print] C:\Users\bekir.oruc\AndroidStudioProjects\nuqud_mobile\build\bluetooth_print\intermediates\library_manifest\debug\AndroidManifest.xml as the library might be using APIs not available in 16
Suggestion: use a compatible library with a minSdk of at most 16,
or increase this project's minSdk version to at least 21,
or use tools:overrideLibrary="com.example.bluetooth_print" to force usage (may lead to runtime failures)

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

Hello, Thank you for bluetooth_print plugin, I am interested and testing the plugin in Android and iOS, mean while I am realizing that we need to select the device on every launch of application, to avoid this, how to save _device instance for ever until disconnect the device.

Thanks.

Wrong place.

Flutter 1.17.4 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 1ad9baa (2 weeks ago) • 2020-06-17 14:41:16 -0700
Engine • revision ee76268252
Tools • Dart 2.8.4

Hi,
Have you checked the QR Code printing? I tried to pass a set of string to print as QR Code, but it prints as normal text instead QRCode.

Please help me on this.

Thanks
Elango.

How can i open cash drawer similar to esc_pos_bluetooth "printer.drawer()"?
Thanks in advance.

OTHER_LDFLAGS里已经有了-l"GSDK"

但是编译时候提示
library not found for -lGSDK

复现步骤：

• 1. 下载此GitHub项目到电脑上
• 2. 运行项目到Android手机上，使用此app连接蓝牙打印设备：“无法与‘xxx’进行配对”
• 3. 运行项目到iOS手机上，使用此app连接蓝牙打印设备，成功地连接；使用此app进行打印数据，打印出的效果不能使用：出现了火星文-->如下图所示

急急急！

It detects me if there is a device connected but it does not load the information of the devices. scanResults is empty.

here is my build.gradle file
` compileSdkVersion 29

sourceSets {
    main.java.srcDirs += 'src/main/kotlin'
}

lintOptions {
    disable 'InvalidPackage'
}

defaultConfig {
    // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
    applicationId "com.example.com"
    minSdkVersion 22
    targetSdkVersion 29
    versionCode flutterVersionCode.toInteger()
    versionName flutterVersionName
}`

And When I try to print I get this error Attempt to invoke virtual method 'com.example.bluetooth_print.PrinterCommand com.example.bluetooth_print.DeviceConnFactoryManager.getCurrentPrinterCommand()' on a null object reference E/AndroidRuntime(32188): at com.example.bluetooth_print.BluetoothPrintPlugin$5.run(BluetoothPrintPlugin.java:326) E/AndroidRuntime(32188): at com.example.bluetooth_print.ThreadPool$1.run(ThreadPool.java:78) E/AndroidRuntime(32188): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) E/AndroidRuntime(32188): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) E/AndroidRuntime(32188): at java.lang.Thread.run(Thread.java:919) I/Process (32188): Sending signal. PID: 32188 SIG: 9

Note on android sdk 28 works as expected.

我查看你的源代码发现 这行代码if("barcode".equals(type)){
tsc.add1DBarcode(x, y, LabelCommand.BARCODETYPE.CODE128, 100, LabelCommand.READABEL.EANBEL, LabelCommand.ROTATION.ROTATION_0,"SMARNET");
}
SMARNET已被写死 我该如何给BARCODE类型设置内容呢？

Hello,

we cannot print accents and this is a huge problem.

Mère et Père do not print, they show up as:

M??re P??re

(the ? are upside down however)

the app working fine on android but when i tested with ios it crashed the sec i start searching ...

xcode output :

2020-03-04 17:44:40.310095+0100 Runner[94466:2281835] call method -> startScan
2020-03-04 17:44:40.310386+0100 Runner[94466:2281835] getDevices method -> startScan
2020-03-04 17:44:40.312031+0100 Runner[94466:2281835] *** Assertion failure in -[CBCentralManager initWithDelegate:queue:options:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/MobileBluetoothFramework_Sim/MobileBluetooth-132.8/CoreBluetooth/CoreBluetooth/CBCentralManager.m:230
2020-03-04 17:44:40.326653+0100 Runner[94466:2281835] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'State restoration of CBCentralManager is only allowed for applications that have specified the "bluetooth-central" background mode'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000011345d27e __exceptionPreprocess + 350
	1   libobjc.A.dylib                     0x0000000113251b20 objc_exception_throw + 48
	2   CoreFoundation                      0x000000011345cff8 +[NSException raise:format:arguments:] + 88
	3   Foundation                          0x0000000112c79b51 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191
	4   CoreBluetooth                       0x00000001132ae101 -[CBCentralManager initWithDelegate:queue:options:] + 910
	5   Runner                              0x000000010f47ef0a -[BLEConnecter initParament] + 292
	6   Runner                              0x000000010f47eddc -[BLEConnecter init] + 66
	7   Runner                              0x000000010f48a85d -[ConnecterManager initConnecter:] + 61
	8   Runner                              0x000000010f48a7ee -[ConnecterManager didUpdateState:] + 94
	9   Runner                              0x000000010f486aae -[BluetoothPrintPlugin handleMethodCall:result:] + 1486
	10  Flutter                             0x00000001101ecdb5 Flutter + 581045
	11  Flutter                             0x0000000110180ba0 Flutter + 138144
	12  Flutter                             0x000000011018464e Flutter + 153166
	13  Flutter                             0x00000001101e6969 Flutter + 555369
	14  Flutter                             0x0000000110193b73 Flutter + 215923
	15  Flutter                             0x00000001101988b8 Flutter + 235704
	16  CoreFoundation                      0x00000001133c0b94 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 20
	17  CoreFoundation                      0x00000001133c0882 __CFRunLoopDoTimer + 1026
	18  CoreFoundation                      0x00000001133bfeda __CFRunLoopDoTimers + 266
	19  CoreFoundation                      0x00000001133bac4e __CFRunLoopRun + 2238
	20  CoreFoundation                      0x00000001133ba066 CFRunLoopRunSpecific + 438
	21  GraphicsServices                    0x0000000116a22bb0 GSEventRunModal + 65
	22  UIKitCore                           0x000000011d667d4d UIApplicationMain + 1621
	23  Runner                              0x000000010f47df50 main + 112
	24  libdyld.dylib                       0x00000001141bcc25 start + 1
	25  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

hello,

i am getting this error and it's urgent we fix this bug please

Because build_runner >=2.0.0 depends on timing ^1.0.0 which depends on json_annotation ^4.0.0, build_runner >=2.0.0 requires json_annotation ^4.0.0.

And because bluetooth_print 2.0.0 depends on json_annotation ^3.0.1, build_runner >=2.0.0 is incompatible with bluetooth_print 2.0.0.

So, because cg_passport_management_interface depends on both bluetooth_print 2.0.0 and build_runner 2.0.2, version solving failed.
pub get failed (1; So, because cg_passport_management_interface depends on both bluetooth_print 2.0.0 and build_runner 2.0.2, version solving failed.)
exit code 1

测试打印机是:
品牌:epson
型号:LW-600P
测试的时候发现搜索不到设备。
手机蓝牙功能是开启的，在蓝牙设置里面能扫描到设备

我的蓝牙打印机在打印QRCODE（二维码）中安卓打印的清晰度太低，导致无法正常使用，后来在printContext中把打印浓度的枚举类从7（好像是7）改成了15，之后可以安卓打印二维码就可以非常清晰了。但是现在存在以下问题：
1：无法判断当前蓝牙设备是否已经正常连接，判断结果往往是错的bluetoothPrint.isConnected和bluetoothPrint.state.listen监听的结果汪汪是错的。
2：bluetoothPrint.connect(device)方法中，往往device不是null反而会出现NullException。
3：bluetoothPrint.disconnect()这个方法经常使用时会导致应用直接崩溃掉（闪退）
`import 'package:bluetooth_print/bluetooth_print.dart';
import 'package:bluetooth_print/bluetooth_print_model.dart';
import 'package:flutter_easyloading/flutter_easyloading.dart';
import 'package:guards/bean/BlueJurisdiction.dart';
import 'package:guards/utils/interface/BluetoothFactory.dart';

/// @description BluetoothFactoryImpl
/// @author Activation
/// @Date 2021/1/26 11:14
class BluetoothFactoryImpl implements BluetoothFactory {
BluetoothPrint bluetoothPrint = BluetoothPrint.instance;
bool isConnFlag = false;

@OverRide
Future disconnect() async {
await bluetoothPrint.stopScan();
await bluetoothPrint.disconnect();
await bluetoothPrint.destroy();
}

@OverRide
Future checkBluetoothAccess() async {
bool openFlag = await bluetoothPrint.isOn;

if (!openFlag) {
  //DialogUtil().showMsg(context, "请您先开启蓝牙");
  return BlueJurisdiction(false, "请您先开启蓝牙");
}
bool authorityFlag = await bluetoothPrint.isAvailable;
if (!authorityFlag) {
  //DialogUtil().showMsg(context, "请您先授予蓝牙的使用权限");
  return BlueJurisdiction(false, "请您先授予蓝牙的使用权限");
}
return BlueJurisdiction(true, "可以连接蓝牙");
//bluetoothPrint.isConnected.then((value) => print(value));

}

@OverRide
Future joinBluetooth() async {
EasyLoading.show(status: "连接蓝牙中。。");
try {
await bluetoothPrint.startScan(timeout: Duration(seconds: 4));
Stream<List> tempStream = bluetoothPrint.scanResults;
print(tempStream);
bool tempFlag = false;
//执行自动连接
tempStream.listen((event) async {
for (BluetoothDevice device in event) {
if (device.name.startsWith(r"Printer_")) {
tempFlag = true;
if (tempFlag && device != null) {
// await bluetoothPrint.disconnect();
print("这里是连接的设备信息$device");
await bluetoothPrint.connect(device);
await bluetoothPrint.stopScan();
}
}
}
});
await bluetoothPrint.isConnected.then((value) {
print("这里是对应的当前值是否已经连接的返回值$value");
});
bluetoothPrint.state.listen((state) {
print("这里是正在监听值的变化$state");
switch (state) {
case BluetoothPrint.CONNECTED:
print("蓝牙已经连接了");
isConnFlag = true;
break;
case BluetoothPrint.DISCONNECTED:
isConnFlag = false;
print("蓝牙还没有连接");
break;
default:
break;
}
});
} catch (e) {
print("这里是对应的异常信息");
print("${e.runtimeType}${e.toString()}");
} finally {
EasyLoading.dismiss();
}
}

@OverRide
Future executePrint(List tempLists) async {
print("这里已经执行了$isConnFlag");
if (isConnFlag) {
await bluetoothPrint.printLabel(config, tempLists);
} else {
throw Exception("当前设备未连接，请关闭蓝牙之后再重试");
// await joinBluetooth().then((value) {
// bluetoothPrint.printLabel(config, tempLists);
// });
}
}

@OverRide
Map<String, dynamic> config = {'width': 300, 'height': 220, 'gap': 30};
}
`
然后我希望您能联系我，我可以协助您完善这个组件，因为我也需要使用这个组件，并且希望他可以成熟。
我的打印机型号为：GP-M322
我的QQ：1067252205
还有楼主的群号重新发下吧。。。。。 我也想进群交流讨论

Able to Connect to the Bluetooth Printer, but unable to print, any solution

兼容/适配：是否支持android 与 iOS 与Web 多端的多种蓝牙设备

是否支持：Android
是否支持：iOS
是否支持：web
是否支持：Android 连接不同型号的蓝牙设备
是否支持：iOS 连接不同型号的蓝牙设备
是否支持：Web 连接不同型号的蓝牙设备

Print as empty space. Testing with the example provided.

Model: amazon link
Specifications:
Model: POS-5802DD
Printing Method: Direct Thermal
Speed: =<90mm/sec
Resolution: 203dpi(8dot/mm)
Paper Type: Thermal Paper
Paper Width: 58mm(+-0.1mm)
Printing Width: 40mm(384dot)
Roll Diameter: =<40mm
Reliability TPH Life: 100km
BT Version: 4.0 & 3.0
Character size: 384dots/line
Font A: 12 * 24dots, 1.5(W) * 3.0(H)mm
Font B: 9 17dots, 1.1(W) 2.1(H)mm
Simplified/Traditional: 24 * 24dots, 3.0(W)*3.0(H)
Extended Character: OEM437/Katakana/OEM850/OEM860/OEM863/OEM865/West Europe/Greek/Hebrew/East Europe/Iran/WPC1252/OEM866/OEM852/OEM858/Iran II/Latvian/Arabic/PT151,1251/OEM747/WPC1257/Vietnam/OEM864/Hebrew/WPC1255/Thai
Print Parameters: Support to download trademark, support bar-code print.
Support Bar Code Type: UPC-A/UPC-E/JAN13(EAN13)/JAN8(EAN8)/CODE39/ITF/CODABAR/CODE93/CODE128;Two-Dimensional Cord: QR Code
Emulation: ESC/POS/STAR Command
Interface: USB/Serial/Power Port
Driver: For Win2003/Win2000/Win7/Win XP/VISTA/Win8/Win10/LINUX
Battery: 7.4V 1500mAh 11.1Wh (Included)
AC Input: 100 ~ 240V 50/60Hz 0.5A max.
Output: DC 9V/1.5A

Hello, I can't print x, y positions for reciept and label mode, kindly give me an example.

字体大小无法调节

Hi, I've tried a lot of command to increase text, including weight and size when I create LineText, I don't know if there are other commands to increase this, but I don't found it and if you can include this possibility in your code would be great. (I test only in esc mode)

hello, I have try with size paper 58mm, and try to control size of image, how to do that

**> /android/app/src/debug/AndroidManifest.xml Error:

    uses-sdk:minSdkVersion 16 cannot be smaller than version 18 declared in library [:bluetooth_print]**

I stuck on this error in 2 days. I found the solution to this issue.

Open printer_app/android/build.gradle:
Change the following line as lower version.

android {
    compileSdkVersion 28

    defaultConfig {
        minSdkVersion 16  // Before it was 18
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    lintOptions {
        disable 'InvalidPackage'
    }
}

However, I found the solution. I don't understand minSdk problem.