Android BLE特徵setValue無法寫入正確的數據

Question

我正在嘗試開發一個Android應用程序，該應用程序使用BLE連接到基於NRF51822的系統。目的是爲我的自定義特性寫一個3字節的值（RGB）。

Android是GATT客戶端，基於NRF51的設備是GATT服務器。

我能夠建立ble連接併成功發現我的特徵。

但是數據發送部分（setValue）給我帶來麻煩。不管我寫什麼3個字節，我上NRF51側

下同常量數據是我rellevant碼（安卓）

@Override 
public void onServicesDiscovered(BluetoothGatt gatt, int status) { 
     Log.d("BLENotifier", "BLE GAT : SERVICES DISCOVERED"); 
     for(BluetoothGattService gs: gatt.getServices()) { 
      Log.d("BLENotifier", "SERVICE = " + gs.getUuid().toString()); 
     } 
     //SELECT MY CHARACTERSTIC 
     ble_my_characterstic = gatt.getService(ble_service_uuid).getCharacteristic(ble_characterstic_uuid); 
     Log.d("BLENotifier", "BLE SELECTED CHARACTERSTIC " + ble_my_characterstic.getUuid().toString()); 
     ble_connected = true; 
    } 

public void writedata(String data){ 
    //WRITE DATA TO MY CHARACTERSTIC 
    if(ble_my_characterstic != null && ble_connected == true){ 

     my_gatt_handle.executeReliableWrite(); 
     //ble_my_characterstic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE); 
     ble_my_characterstic.setValue(hexStringToByteArray(data)); 
     my_gatt_handle.writeCharacteristic(ble_my_characterstic); 

     Log.d("BLENotifier", "BLE WRITE DATA " + data); 
    } 

public static byte[] hexStringToByteArray(String s) { 
    int len = s.length(); 
    byte[] data = new byte[len/2]; 
    for (int i = 0; i < len; i += 2) { 
     data[i/2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) 
       + Character.digit(s.charAt(i+1), 16)); 
    } 
    Log.d("BLENotifier", "hexStringToByteArray " + Integer.toString((int)data[0]) + " " + Integer.toString((int)data[1]) + " " + Integer.toString((int)data[2])); 
    return data; 
} 

我調用writeData方法ble_handle.writedata("0000FF")

這就是我得到的NRF51側

R = 4 | G = 239 | B= 1 

感謝

Answer 1

我的確如此。沒有確切答案，但可能會對您有所幫助。

@Override 
    public void onServicesDiscovered(BluetoothGatt gatt, int status) 
    { 
     List<BluetoothGattService> services = gatt.getServices(); 
     Log.i("onServicesDiscovered", services.toString()); 
     keepConnect=services.get(3).getCharacteristics().get(0); 
     if(keepConnect!=null){ 
      writeCharacteristic(gatt,keepConnect); 
     } 
    } 

    private void writeCharacteristic(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) 
    { 

     byte[] byteData = hexToBytes("6fd362e40ebcd0945bf58dc4"); 
     byte[] writeData = new byte[byteData.length]; 
     for (int i = 0; i < byteData.length; i++) { 
      writeData[i] = byteData[i]; 
     } 
     characteristic.setValue(writeData); 
     gatt.writeCharacteristic(characteristic);  

    } 

public static byte[] hexToBytes(String hexRepresentation) { 
    int len = hexRepresentation.length(); 
    byte[] data = new byte[len/2]; 

    for (int i = 0; i < len; i += 2) { 
     data[i/2] = (byte) ((Character.digit(hexRepresentation.charAt(i), 16) << 4) 
       + Character.digit(hexRepresentation.charAt(i + 1), 16)); 
    } 

    return data; 
}