BLE Android写入特征数据

Question

我正在使用Android进行BLE项目。 我想写入特征数据并将其发送到BLE芯片。

我想改写ISEN_Toulon

我使用此代码编写了特征数据，但是"ISEN_Toulon"预期将数据"ISEN_Toulon"替换为"TEST" 。

private BluetoothGattCharacteristic mWriteCharacteristic;

private final ExpandableListView.OnChildClickListener servicesListClickListner =
        new ExpandableListView.OnChildClickListener()
        {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition,int childPosition, long id)
            {
                if (mGattCharacteristics != null) {
                    final BluetoothGattCharacteristic characteristic = mGattCharacteristics.get(groupPosition).get(childPosition);
                    final int charaProp = characteristic.getProperties();
.....
                    // READ
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
                        // If there is an active notification on a characteristic, clear
                        // it first so it doesn't update the data field on the user interface.
                        if (mNotifyCharacteristic != null) {
                            mBluetoothLeService.setCharacteristicNotification(
                                    mNotifyCharacteristic, false);
                            mNotifyCharacteristic = null;
                        }
                        mBluetoothLeService.readCharacteristic(characteristic);
                        Log.d("myTag", "1");
                    }
                    // NOTIFY
                    if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
                        mNotifyCharacteristic = characteristic;
                        mBluetoothLeService.setCharacteristicNotification(
                                characteristic, true);
                        Log.d("myTag", "2");
                    }

                    // WRITE  
                    characteristic.setWriteType(BluetoothGattCharacteristic.PROPERTY_WRITE);
                    characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
                    characteristic.setWriteType(BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE);

                    mWriteCharacteristic = characteristic;

                    String str = "TEST";
                    byte[] strBytes = str.getBytes();
                    characteristic.setValue(strBytes);
                    writeCharacteristic(characteristic)

                    return true;
                }
                return false;
            }
};

Answer 1

我也遇到过同样的问题。 解决问题的详细方式我不记得了。 但是我有一个代码可以将BLE特性写入BLE设备，如下所示:(至少对我有用）

    public OnClickListener clickListener = new OnClickListener() {

    @Override
    public void onClick(View arg0) {
        // TODO Auto-generated method stub
        if (mGattCharacteristics != null) {
            if(charas.size()>=6){
                BluetoothGattCharacteristic characteristic =
                        charas.get(0);
                BluetoothGattCharacteristic characteristic_write = charas.get(5);
                int charaProp_write = characteristic_write.getProperties();
                int charaProp = characteristic.getProperties();
                //String getUUID = characteristic.getUuid().toString();
                if (((charaProp_write | BluetoothGattCharacteristic.PROPERTY_WRITE) > 0)
                        &&  
                        (characteristic_write != null)){

                    if (mNotifyCharacteristic != null) {
                        mBluetoothLeService.setCharacteristicNotification(
                                mNotifyCharacteristic, false);
                        mNotifyCharacteristic = null;
                    }   
                    byte[] writev = new byte[SIMPLEPROFILE_CHAR6_LEN];
                    Arrays.fill(writev, (byte)'0');
                    byte[] getedit1 = edit1.getText().toString().getBytes();//edit1.getText().toString().getBytes();
                    byte[] getedit2 = edit2.getText().toString().getBytes();
                    byte[] getedit3 = edit3.getText().toString().getBytes();


                    //System.out.println(getedit1 + " " + getedit2 + " " + getedit3);

                    if ((getedit1.length + getedit2.length + getedit3.length) <= (max_syvlength+max_spvlength+max_tuvlength)) {
                        //this 'if' can be canceled
                        writev[0] = (byte)'1';
                        writev[1] = (byte)(getedit1.length);
                        writev[2] = (byte)(getedit2.length);
                        writev[3] = (byte)(getedit3.length);
                        System.arraycopy(getedit1, 0, writev, 4, getedit1.length);
                        System.arraycopy(getedit2, 0, writev, 4 + getedit1.length, getedit2.length);
                        System.arraycopy(getedit3, 0, writev, 4 + getedit1.length + getedit2.length, getedit3.length);
                        writev[4 + getedit1.length + getedit2.length + getedit3.length] = '@';
                    }

                    /*
                    for(int i = 0;i<15;i++){
                        Log.d(TAG, "is:" + writev[i]);
                    }
                    */                      

                    characteristic_write.setValue(writev);
                    characteristic_write.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
                    mBluetoothLeService.writeCharacteristic(characteristic_write);

                }
                if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
                    // If there is an active notification on a characteristic, clear
                    // it first so it doesn't update the data field on the user interface.
                    if (mNotifyCharacteristic != null) {
                        mBluetoothLeService.setCharacteristicNotification(
                                mNotifyCharacteristic, false);
                        mNotifyCharacteristic = null;
                    }
                    mBluetoothLeService.readCharacteristic(characteristic);

                }       
                if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
                    mNotifyCharacteristic = characteristic;
                    mBluetoothLeService.setCharacteristicNotification(
                            characteristic, true);
                }

            }
        }

        GotoMyActivity();

    }
};

Answer 2

试图覆盖回调函数

BluetoothGattCallback mGattCallback = new BluetoothGattCallback(){
//something callback function like:

@Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
      //do something read/write
}

您需要弄清楚BLE回调函数的工作原理！！！ 检查这个出来。

因为BLE写入/读取只能一次完成。 这意味着如果我从特征读取数据。 在上一个操作完成后，我只能执行另一个写/读操作。

Answer 3

您的情况是将多个字节的数据写入特征到蓝牙设备，该规则很少：

1. Android无法将并行数据包写入ble设备。
2. 数据不得超过20个字节
3. 您应该将数据分成多个块并发送到ble设备
4. 在发送下一个要写入ble设备的数据包之前，您应该等待onCharacteristicWrite（）的写回调 。

Answer 4

我知道这很老了，但是由于我今天有一个类似的问题，其他人可能希望得到答案。

您设置WriteType 3次的问题-实际上覆盖了第一个设置的值。 您的代码：

...
characteristic.setWriteType(BluetoothGattCharacteristic.PROPERTY_WRITE);
characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
characteristic.setWriteType(BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE);

两个问题：

• 以PROPERTY_开头的值不是写类型，因此只有WRITE_TYPE_NO_RESPONSE有效
• 第三次调用setWriteType()用无效值覆盖有效值，然后Android堆栈会忽略您的写入请求。

除非有特定的原因使用WRITE_NO_RESPONSE ，否则应使用普通写入（ WRITE_TYPE_DEFAULT ）。 Android堆栈有时会错过一次写操作-例如在应用程序中会调用写操作5次，但是只有1或2个写操作是通过空中发送的。 即使onCharacteristicWrite()回调报告成功也是如此。

characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT);