特征不能被多次写入

Question

我正在创建一个简单的应用程序，它将输入从游戏控制器传输到 HM-10 蓝牙模块。代码应该在每次检测到新输入时写入一个包含输入数据的特征，但起初 writeCharacteristic 失败了几次，然后它写入一次特征，一次成功写入后，任何其他尝试写入一个特性不起作用。

代码如下：

package com.example.fifaksbestbluetoothcontroller;

import static java.lang.Math.round;

import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.polidea.rxandroidble2.RxBleClient;
import com.polidea.rxandroidble2.RxBleDevice;

import java.nio.charset.StandardCharsets;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

    RxBleClient rxBleClient;
    RxBleDevice rxBleDevice;
    UUID characteristicUuid = UUID.fromString("0000ffe1-0000-1000-8000-00805f9b34fb");


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rxBleClient = RxBleClient.create(this);
    }

    @Override
    public boolean onGenericMotionEvent(MotionEvent event) {

        // Check that the event came from a game controller

        float steeringInput = round(event.getAxisValue(MotionEvent.AXIS_X) * 100);
        steeringInput = steeringInput / 100;
        float throttleInput = round(event.getAxisValue(MotionEvent.AXIS_GAS) * 100 - event.getAxisValue(MotionEvent.AXIS_BRAKE) * 100);
        throttleInput = throttleInput / 100;
        String toWrite = steeringInput + "F" + throttleInput + "F";
        byte[] realToWrite = toWrite.getBytes(StandardCharsets.UTF_8);
        TextView textView = findViewById(R.id.BRUH);
        textView.setText(new String(realToWrite));

        rxBleDevice = rxBleClient.getBleDevice("18:93:D7:11:43:DF");
        rxBleDevice.establishConnection(false)
                .flatMapSingle(rxBleConnection -> rxBleConnection.writeCharacteristic(characteristicUuid, realToWrite)).retry(100)
                .subscribe(
                        characteristicValue -> Log.v("myTag", "the data was sent"),
                        throwable -> Log.v("myTag", "the data wasn't sent")
                );
        return true;
    }

}

我不知道如何解决这个问题，因为我找不到任何基于 Logcat 的解决方案。

这是 Logcat 的片段：

2021-11-06 22:13:01.857 32604-32665/? D/bt_btif: bta_av_ssm_execute(): AV Sevent(0x41)=0x1229(AVDT_DELAY_RPT) state=3(OPEN)
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_audio_delay: handle: x41, delay:0x65d
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_get_active_peer: active peer index: 0
2021-11-06 22:13:01.857 32604-32665/? I/btif_av: isBATEnabled: 0
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_get_active_peer: active peer index: 0
2021-11-06 22:13:01.857 32604-32665/? I/chatty: uid=1002(bluetooth) btu message loo identical 2 lines
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_get_active_peer: active peer index: 0
2021-11-06 22:13:01.857 705-705/? I/vendor.qti.bluetooth@1.0-ibs_handler: DeviceWakeUp: Writing IBS_WAKE_IND
2021-11-06 22:13:01.857 32604-32665/? I/btif_av: isBATEnabled: 0
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_get_active_peer: active peer index: 0
2021-11-06 22:13:01.857 32604-32665/? E/bt_btif: bta_av_co_get_active_peer: active peer index: 0
2021-11-06 22:13:01.857 32604-32665/? I/bt_stack: [INFO:a2dp_encoding.cc(1370)] set_remote_delay: DELAY 162.9 ms
2021-11-06 22:13:01.857 705-32662/? I/vendor.qti.bluetooth@1.0-ibs_handler: ProcessIbsCmd: Received IBS_WAKE_ACK: 0xFC
2021-11-06 22:13:01.858 702-8805/? I/BTAudioProviderSession: OnSessionParamUpdate Update Sink Latency: 1629
2021-11-06 22:13:01.889 1826-2276/? W/BaseMiuiPhoneWindowManager: keyCode:105 down:true eventTime:1244197974 downTime:1244197974 policyFlags:22000001 flags:8 deviceId:57 isScreenOn:true keyguardActive:false repeatCount:0
2021-11-06 22:13:01.895 19384-20187/? D/BluetoothGatt: connect() - device: 18:93:D7:11:43:DF, auto: false
2021-11-06 22:13:01.896 19384-20187/? D/BluetoothGatt: registerApp()
2021-11-06 22:13:01.896 19384-20187/? D/BluetoothGatt: registerApp() - UUID=d1c2e3e7-5505-42d1-824d-3ff2a8c97dcb
2021-11-06 22:13:01.897 6594-6594/? D/AudioManager: getStreamVolume isRestricted mode = 0
2021-11-06 22:13:01.898 32604-364/? D/BtGatt.GattService: registerClient() - UUID=d1c2e3e7-5505-42d1-824d-3ff2a8c97dcb
2021-11-06 22:13:01.899 32604-32665/? I/bt_stack: [INFO:gatt_api.cc(957)] GATT_Register 592b908d-0565-f4ce-989f-2f3d65f8540b
2021-11-06 22:13:01.899 32604-32665/? I/bt_stack: [INFO:gatt_api.cc(977)] allocated gatt_if=10
2021-11-06 22:13:01.899 6594-6594/? D/AudioManager: getStreamVolume isRestricted mode = 0
2021-11-06 22:13:01.900 32604-32639/? D/BtGatt.GattService: onClientRegistered() - UUID=d1c2e3e7-5505-42d1-824d-3ff2a8c97dcb, clientIf=10
2021-11-06 22:13:01.900 19384-19417/? D/BluetoothGatt: onClientRegistered() - status=0 clientIf=10
2021-11-06 22:13:01.901 32604-364/? D/BtGatt.GattService: clientConnect() - address=18:93:D7:11:43:DF, isDirect=true, opportunistic=false, phy=1
2021-11-06 22:13:01.901 32604-32639/? D/bt_btif_config: btif_get_address_type: Device [18:93:d7:11:43:df] address type 0
2021-11-06 22:13:01.901 32604-32639/? D/bt_btif_config: btif_get_device_type: Device [18:93:d7:11:43:df] type 2
2021-11-06 22:13:01.901 32604-32665/? I/bt_stack: [INFO:gatt_api.cc(1129)] GATT_Connect gatt_if=10, address=18:93:d7:11:43:df is_direct 1
2021-11-06 22:13:01.902 32604-32639/? D/BtGatt.GattService: onConnected() - clientIf=10, connId=10, address=18:93:D7:11:43:DF
2021-11-06 22:13:01.905 19384-19417/? D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=10 device=18:93:D7:11:43:DF
2021-11-06 22:13:01.908 19384-19384/? D/myTag: the data wasn't sent
2021-11-06 22:13:01.908 19384-20187/? D/BluetoothGatt: discoverServices() - device: 18:93:D7:11:43:DF
2021-11-06 22:13:01.909 32604-364/? D/BtGatt.GattService: discoverServices() - address=18:93:D7:11:43:DF, connId=10
2021-11-06 22:13:01.910 32604-32639/? D/BtGatt.GattService: onSearchCompleted() - connId=10, status=0
2021-11-06 22:13:01.911 32604-32639/? D/bt_bta_gattc: bta_gattc_get_gatt_db
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: onGetGattDb() - address=18:93:D7:11:43:DF
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got service with UUID=00001800-0000-1000-8000-00805f9b34fb id: 1
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a00-0000-1000-8000-00805f9b34fb id: 3
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a01-0000-1000-8000-00805f9b34fb id: 5
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a02-0000-1000-8000-00805f9b34fb id: 7
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a03-0000-1000-8000-00805f9b34fb id: 9
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a04-0000-1000-8000-00805f9b34fb id: 11
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got service with UUID=00001801-0000-1000-8000-00805f9b34fb id: 12
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a05-0000-1000-8000-00805f9b34fb id: 14
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got descriptor with UUID=00002902-0000-1000-8000-00805f9b34fb id: 15
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got service with UUID=0000180a-0000-1000-8000-00805f9b34fb id: 16
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a23-0000-1000-8000-00805f9b34fb id: 18
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a24-0000-1000-8000-00805f9b34fb id: 20
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a25-0000-1000-8000-00805f9b34fb id: 22
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a26-0000-1000-8000-00805f9b34fb id: 24
2021-11-06 22:13:01.911 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a27-0000-1000-8000-00805f9b34fb id: 26
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a28-0000-1000-8000-00805f9b34fb id: 28
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a29-0000-1000-8000-00805f9b34fb id: 30
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a2a-0000-1000-8000-00805f9b34fb id: 32
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=00002a50-0000-1000-8000-00805f9b34fb id: 34
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got service with UUID=0000ffe0-0000-1000-8000-00805f9b34fb id: 35
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got characteristic with UUID=0000ffe1-0000-1000-8000-00805f9b34fb id: 37
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got descriptor with UUID=00002902-0000-1000-8000-00805f9b34fb id: 38
2021-11-06 22:13:01.912 32604-32639/? D/BtGatt.GattService: got descriptor with UUID=00002901-0000-1000-8000-00805f9b34fb id: 39
2021-11-06 22:13:01.913 19384-19417/? D/BluetoothGatt: onSearchComplete() = Device=18:93:D7:11:43:DF Status=0
2021-11-06 22:13:01.918 19384-20186/? D/myTag: the data was sent
2021-11-06 22:13:01.941 19384-19384/? D/myTag: the data wasn't sent
2021-11-06 22:13:01.974 19384-19384/? I/chatty: uid=10483(com.example.fifaksbestbluetoothcontroller) identical 1 line
2021-11-06 22:13:02.007 19384-19384/? D/myTag: the data wasn't sent
2021-11-06 22:13:02.065 523-523/? I/hwservicemanager: getTransport: Cannot find entry vendor.qti.hardware.servicetracker@1.0::IServicetracker/default in either framework or device manifest.
2021-11-06 22:13:02.107 19384-19384/? D/myTag: the data wasn't sent
2021-11-06 22:13:02.139 6594-6594/? D/AudioManager: getStreamVolume isRestricted mode = 0
2021-11-06 22:13:02.140 19384-19384/? D/myTag: the data wasn't sent
2021-11-06 22:13:02.142 6594-6594/? D/AudioManager: getStreamVolume isRestricted mode = 0
2021-11-06 22:13:02.151 2769-2769/? D/QtiCarrierConfigHelper: WARNING, no carrier configs on phone Id: 0
2021-11-06 22:13:02.151 4171-4171/? D/NfcService: Received android.intent.action.BATTERY_CHANGED

如有任何帮助，我们将不胜感激。

Answer 1

如果您检查 throwable，您可能会看到 BleAlreadyConnectedException。

如果是这种情况，您希望建立 RxBleConnection 一次重用它。要通过重用连接发送数据，您可以使用 RxReplayingShare 或将 onMotionEvent() 包装到 Observable<MotionEvent> 中并将其整理到 Observable 链中。

Observable.combineLatest(
    motionEventObservable,
    rxBleDevice.establishConnection(false),
    (motionEvent, connection) -> {
        float steeringInput = round(event.getAxisValue(MotionEvent.AXIS_X) * 100);
        steeringInput = steeringInput / 100;
        float throttleInput = round(event.getAxisValue(MotionEvent.AXIS_GAS) * 100 - event.getAxisValue(MotionEvent.AXIS_BRAKE) * 100);
        throttleInput = throttleInput / 100;
        String toWrite = steeringInput + "F" + throttleInput + "F";
        byte[] realToWrite = toWrite.getBytes(StandardCharsets.UTF_8);
        return rxBleConnection.writeCharacteristic(characteristicUuid, realToWrite);
    }
)
    .flatMapSingle(it -> it)
    .subscribe(
        characteristicValue -> Log.v("myTag", "the data was sent"),
        throwable -> Log.v("myTag", "the data wasn't sent", throwable) // check what is the problem!
    );

特征不能被多次写入

Characteristic cant be written more than once

java

android

bluetooth-lowenergy

rxandroidble