在过去的6个月里,我正在研究BLE应用程序。 在我最近的项目中,我正在集成一个自定义BLE设备,它在读取数据时会产生同步问题。 “onCharacteristicRead”始终返回133错误代码。请仔细阅读完整的方案,如果有人有任何解决方案,请帮助我。
情景 定制BLE设备有三种服务可用。
紧急
全部抓住
电池电量
我的申请中只需要两项服务。电池和紧急情况。 最初,我将使用以下代码扫描设备,
private void scan() {
if (isLollyPopOrAbove()) {// Start Scanning For Lollipop devices
mBluetoothAdapter.getBluetoothLeScanner().startScan(scanFilters(), scanSettings(), scanCallback); // Start BLE device Scanning in a separate thread
} else {
mBluetoothAdapter.startLeScan(mLeScanCallback); // Start Scanning for Below Lollipop device
}
}
private List<ScanFilter> scanFilters() {
String emergencyUDID = "3C02E2A5-BB87-4BE0-ADA5-526EF4C14AAA";
ScanFilter filter = new ScanFilter.Builder().setServiceUuid(ParcelUuid.fromString(emergencyUDID)).build();
List<ScanFilter> list = new ArrayList<ScanFilter>(1);
list.add(filter);
return list;
}
private ScanSettings scanSettings() {
ScanSettings settings = new ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_BALANCED).build();
return settings;
}
这工作正常,我得到扫描结果,我可以连接到设备。一旦连接建立,我将从GattCallBack进行以下调用
mBluetoothGatt.discoverServices();
然后我得到服务发现完成回调
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) { //BLE service discovery complete
if (status == BluetoothGatt.GATT_SUCCESS) { //See if the service discovery was successful
Log.i(TAG, "**ACTION_SERVICE_DISCOVERED**" + status);
broadcastUpdate(BLEConstants.ACTION_GATT_SERVICES_DISCOVERED); //Go broadcast an intent to say we have discovered services
} else { //Service discovery failed so log a warning
Log.i(TAG, "onServicesDiscovered received: " + status);
}
}
从这里,我使用提供的UUID找到可用的MLDP服务。这也很好。
但是当我读到特色时,
public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) { //Check that we have access to a Bluetooth radio
return;
}
boolean status = mBluetoothGatt.readCharacteristic(characteristic); //Request the BluetoothGatt to Read the characteristic
Log.i(TAG, "READ STATUS " + status);
}
响应状态变为true,但“onCharacteristicRead”回调始终为133
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) { //A request to Read has completed
//String value = characteristic.getStringValue(0);
//int value = characteristic.getIntValue(BluetoothGattCharacteristic.FORMAT_UINT32, 0);
// if(characteristic.getUuid().e)
if (status == BluetoothGatt.GATT_SUCCESS) {
//See if the read was successful
Log.i(TAG, "**ACTION_DATA_READ**" + characteristic);
broadcastUpdate(BLEConstants.ACTION_DATA_AVAILABLE, characteristic); //Go broadcast an intent with the characteristic data
} else {
Log.i(TAG, "ACTION_DATA_READ: Error" + status);
}
}
答案 0 :(得分:2)
最后,我找到了解决133错误的解决方案。在深入分析期间,我发现BLE请求响应过程有一些延迟。所以我为每次读写设置了500毫秒的延迟。现在它完美无缺。我已经在各种设备上测试了它的工作原理。我不知道这是否是一种解决方法。但这可能对面临类似问题的开发人员有所帮助。
答案 1 :(得分:1)
错误代码:133表示GATT__ERROR,设备不在范围内。读取事件期间可能存在错误。我建议先从设备方面查看。
一个问题:这个设备需要绑定连接吗?