CC2541 GATT_WriteNoRsp and Android phone link

請問在 Keyfob 源碼內要增加 Button 按鍵，程式如下:

  attWriteReq_t writeReq;

  writeReq.handle = 3;
  writeReq.len = 1;
  writeReq.value[0] = 0x02;
  writeReq.sig = 0;
  writeReq.cmd = 1;
 
  GATT_WriteNoRsp(0, &writeReq);

當連接 android APP 無法收到按事件觸發鍵通知 ,我使用android 程式如下

private BluetoothGattServerCallback mGattServerCallbacks = new BluetoothGattServerCallback() {
      
        @Override
        public void onCharacteristicWriteRequest(BluetoothDevice device, int requestId, BluetoothGattCharacteristic characteristic, boolean preparedWrite, boolean responseNeeded, int offset,
                byte[] value) {

            final int receivedValue = value[0];
            if (receivedValue != 0x00) {
                Logger.i(mLogSession, "[Proximity Server] Immediate alarm request received: ON");
                playAlarm();
            } else {
                Logger.i(mLogSession, "[Proximity Server] Immediate alarm request received: OFF");
                stopAlarm();
            }
        }

請問以上(GATT_WriteNoRsp) 作法有何錯誤?