bluetoothGatt.writeCharacteristic始终返回false，且ble特征类型为write_no_reponse
bluetoothGatt.writeCharacteristic始终返回false，且ble特征类型为write_no_reponse
提问于 2019-08-07 10:02:57
我正在写一个Android应用程序来与BLE仪表交谈。我已经能够扫描设备，连接到目标，发现服务，获取特征。但是，当我尝试编写write_no_reponse特征时，该方法总是返回false。我相信它的特性是可写的，我用别人的app来写。当我调试成android.bluetooth代码时，下面的序列出现了故障，可能它返回了一个空服务，debug运行到这个步骤，然后单步退出方法：
BluetoothGattService service = characteristic.getService(); 这会导致writeCharacteristic返回false。但是在writeCharacteristic之前，我有一个日志
Log.d(TAG, "onServicesDiscovered: writeType" + mCharacteristic.getService());
bluetoothGatt.writeCharacteristic(mCharacteristic);且日志正确且不返回null；
任何帮助都是非常感谢的！
并且我用同样的代码写出了一个写特性，很管用。我试着使用
mCharacteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);来设置写入类型，但也失败了。
写入数据代码：
public void writeReadDataCommand() {
if (null != bluetoothGatt) {
mCharacteristic.setValue("123123");
bluetoothGatt.setCharacteristicNotification(mCharacteristic, true);
mCharacteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
Log.d(TAG, "onServicesDiscovered: writeType" + mCharacteristic.getService());
boolean isWrite = bluetoothGatt.writeCharacteristic(mCharacteristic);
if (isWrite) {
Log.d(TAG, "writeReadDataCommand: write data to BLE");
}
}
}onServiceDiscovered代码：
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
super.onServicesDiscovered(gatt, status);
if (status == BluetoothGatt.GATT_SUCCESS) {
bluetoothGatt = gatt;
BluetoothGattService service = gatt.getService(UUID.fromString(SERVICE_UUID));
BluetoothGattCharacteristic characteristic = service.getCharacteristic(UUID.fromString(CHARACTERISTIC_UUID));
Log.d(TAG, "onServicesDiscovered: writeType" + characteristic.getWriteType());
boolean isSuccess = gatt.setCharacteristicNotification(characteristic, true);
if (isSuccess) {
mCharacteristic = characteristic;
List<BluetoothGattDescriptor> descriptors = characteristic.getDescriptors();
if (null != descriptors && descriptors.size() > 0) {
for (BluetoothGattDescriptor descriptor : descriptors) {
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
gatt.writeDescriptor(descriptor);
}
}
}
connectCallback.findService();
} else {
Log.d(TAG, "onServicesDiscovered received: " + status);
}
}并且onCharacteristicWrite回调不会触发
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
Log.d(TAG, "onCharacteristicWrite: " + Arrays.toString(characteristic.getValue()));
}我已经有这个bug很长时间了，非常感谢如果有人能帮助我。
回答 2
Stack Overflow用户
发布于 2019-08-07 20:19:28
如图所示，我的服务中有两个特征-- 0和1。这两个特征具有相同的uuid。我做的第一件事是
BluetoothGattCharacteristic characteristic = service.getCharacteristic(UUID.fromString(CHARACTERISTIC_UUID));这段代码找到了0的特征，然后我把数据写到it.Obviously，我失败了。因为0特性只能读取和通知。因此，我执行以下步骤将日期写入BLE
characteristics = service.getCharacteristics();
for(BluetoothGattCharacteristic characteristic : characteristics){
if(characteristic.getUuid().equals(UUID.fromString(CHARACTERISTIC_UUID))){
enableNotification(characteristic);
}
} for(BluetoothGattCharacteristic characteristic : characteristics){
if(characteristic.getUuid().equals(UUID.fromString(CHARACTERISTIC_UUID))){
characteristic.setValue("123123");
characteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
boolean isWrite = bluetoothGatt.writeCharacteristic(characteristic);
if (isWrite) {
Log.d(TAG, "writeReadDataCommand: write data to ble");
}
}
}我尝试通知这两个特征并将数据写入这两个特征，尽管它们具有相同的UUID，但它们具有不同的功能。显然，一个特征将通知失败，一个特征将写入失败。但最终我成功地写出了我的数据。
Stack Overflow用户
发布于 2021-01-26 21:49:42
在onDescriptorWrite()发送数据到BLE设备后执行。
private final BluetoothGattCallback getGattCallback1=new BluetoothGattCallback() {
@Override
public void onPhyUpdate(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
super.onPhyUpdate(gatt, txPhy, rxPhy, status);
}
@Override
public void onPhyRead(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
super.onPhyRead(gatt, txPhy, rxPhy, status);
}
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
super.onConnectionStateChange(gatt, status, newState);
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
super.onServicesDiscovered(gatt, status);
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
super.onCharacteristicRead(gatt, characteristic, status);
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
super.onCharacteristicWrite(gatt, characteristic, status);
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
super.onCharacteristicChanged(gatt, characteristic);
}
@Override
public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
super.onDescriptorRead(gatt, descriptor, status);
}
@Override
public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
super.onDescriptorWrite(gatt, descriptor, status);
// here send broadcast to MainActivity.That u are ready to write Data To the device.
}
@Override
public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
super.onReliableWriteCompleted(gatt, status);
}
@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
super.onReadRemoteRssi(gatt, rssi, status);
}
@Override
public void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {
super.onMtuChanged(gatt, mtu, status);
}
};
@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
public void setCharacteristicNotifications(BluetoothGatt bluetoothGatt,BluetoothGattCharacteristic characteristic,
boolean enabled,String bleAddress) {
if (mBluetoothAdapter == null || bluetoothGatt == null) {
return;
}
bluetoothGatt.setCharacteristicNotification(characteristic, enabled);
BluetoothGattDescriptor descriptor = null;
descriptor = characteristic.getDescriptor(UUID.fromString(CLIENT_CHARACTERISTIC_CONFIG));
if (descriptor == null) {
enableNotiticationToFirmwareCompleted(false,bleAddress);
return;
}
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
bluetoothGatt.writeDescriptor(descriptor);
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/57386072
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