update doc

README.md

 /**
  Broadcast data decryption method
  */
-byte[] decryptBroadcast(int cid, int vid,int pid, byte[] payload);
+byte[] decryptBroadcast(byte[] payload);
 
 ```
 

README_zh.md

 /**
  广播数据解密方法
  */
-byte[] decryptBroadcast(int cid, int vid,int pid, byte[] payload);
+byte[] decryptBroadcast(byte[] payload);
 
 ```
 

app/src/main/java/com/elinkthings/ailinksecrettooldemo/AnalyticalDataUtil.java

                     SystemClock.sleep(100);
                     BluetoothGattService mGattService = MyBleDeviceUtils.getService(mBluetoothGatt, BleConfig.UUID_SERVER_AILINK);
                     if (mGattService != null) {
-                        BluetoothGattCharacteristic mCharacteristic = MyBleDeviceUtils
-                                .getServiceWrite(mGattService, BleConfig.UUID_WRITE_NOTIFY_AILINK);
+                        BluetoothGattCharacteristic mCharacteristic = MyBleDeviceUtils.getServiceWrite(mGattService, BleConfig.UUID_WRITE_NOTIFY_AILINK);
                         if (mCharacteristic != null) {
                             mCharacteristic.setValue(bytes);
                             mCharacteristic.setWriteType(BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE);
     }
 
 
-
     /**
      * 将广播数据进行解密
      *
-     * @param cid     cid
-     * @param vid     vid
-     * @param pid   pid
      * @param payload byte[]
      * @return byte[]
      */
-    public byte[] decryptBroadcast(int cid, int vid,int pid, byte[] payload) {
-        byte[] data = null;
-        if (payload != null && payload.length >= 1) {
-            data = AiLinkBleCheckUtil.decryptBroadcast(cid, vid, pid,payload);
+    public byte[] decryptBroadcast(byte[] payload) {
+        if (payload != null && payload.length >= 20) {
+            byte[] cidB = new byte[1];
+            byte[] vidB = new byte[1];
+            byte[] pidB = new byte[1];
+            int start = 0;
+            System.arraycopy(payload, start, cidB, 0, cidB.length);
+            start += 1;
+            System.arraycopy(payload, start, vidB, 0, vidB.length);
+            start += 1;
+            System.arraycopy(payload, start, pidB, 0, pidB.length);
+            start += 1;
+            //特殊广播,包含是否可以绑定的标志
+            int cid = (cidB[0] & 0xff);
+            int vid = (vidB[0] & 0xff);
+            int pid = (pidB[0] & 0xff);
+            byte sum = payload[9];
+            byte[] decryptData = new byte[10];//根据协议取出需要解密的广播数据
+            System.arraycopy(payload, 10, decryptData, 0, decryptData.length);
+            byte newSum = cmdSum(decryptData);
+            if (sum == newSum) {
+                byte[] data = AiLinkBleCheckUtil.decryptBroadcast(cid, vid, pid, decryptData);
+                return data;
+            }
         }
-        return data;
+        return payload;
+    }
+
+
+    /**
+     * 校验累加,从1开始加
+     */
+    private static byte cmdSum(byte[] data) {
+        byte sum = 0;
+        for (byte datum : data) {
+            sum += datum;
+        }
+        return sum;
     }
 
     public void close() {

app/src/main/java/com/elinkthings/ailinksecrettooldemo/MainActivity.java

      * @param data 自定义厂商数据
      */
     private void decryptBroadcastExample(byte[] data){
-            if (data.length < 3)
-                return;
-            byte[] cidB = new byte[1];
-            byte[] vidB = new byte[1];
-            byte[] pidB = new byte[1];
-            int start = 0;
-            System.arraycopy(data, start, cidB, 0, cidB.length);
-            start += 1;
-            System.arraycopy(data, start, vidB, 0, vidB.length);
-            start += 1;
-            System.arraycopy(data, start, pidB, 0, pidB.length);
-            start += 1;
-            //特殊广播,包含是否可以绑定的标志
-            int cid = (cidB[0] & 0xff);
-            int vid = (vidB[0] & 0xff);
-            int pid = (pidB[0] & 0xff);
-            byte[] decryptData=new byte[10];//根据协议取出需要解密的广播数据
-            mAnalyticalDataUtil.decryptBroadcast(cid, vid, pid, decryptData);
+           byte[] decryptData= mAnalyticalDataUtil.decryptBroadcast(data);//获取解密后的数据
 
     }