Added support of checksum

tainfante · Dec 22, 2017 · c7e5efd · c7e5efd
1 parent 6c048a8
commit c7e5efd
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Showing 4 changed files with 48 additions and 48 deletions.
diff --git a/.idea/misc.xml b/.idea/misc.xml
diff --git a/src/port/CRC16.java b/src/port/CRC16.java
@@ -4,7 +4,7 @@
 
 public class CRC16
 {
-    int[] crc16ccittTab = {
+    private static int[] crc16ccittTab = {
             0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,
             0x8108,0x9129,0xa14a,0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,
             0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0x62d6,
@@ -48,40 +48,15 @@ public CRC16()
     // ============================================================================================================================
     public int generateCRC16CCITT(ArrayList<Byte> buff)
     {
-        int crc = 0x0000;
-        byte data;
+        int crc = 0;
+        int data;
 
-        for (byte b : buff)
+        for (Byte aBuff : buff)
         {
-            data = (byte)(((crc >> 8) ^ b) & 0x00FF);
-            crc = (crc << 8) ^ crc16ccittTab[data];
+            data = 0xFF & ((((crc & 0xFFFF) >> 8) ^ (aBuff & 0xFF)) & 0x00FF);
+            crc = 0xFFFF & (((crc & 0xFFFF) << 8) ^ crc16ccittTab[data & 0xFF]);
         }
 
-
         return crc;
     }
-
-    int calculate_crc(ArrayList<Byte> bytes) {
-        int i;
-        int crc_value = 0;
-        for (Byte aByte : bytes)
-        {
-            for (i = 0x80; i != 0; i >>= 1)
-            {
-                if ((crc_value & 0x8000) != 0)
-                {
-                    crc_value = (crc_value << 1) ^ 0x8005;
-                }
-                else
-                {
-                    crc_value = crc_value << 1;
-                }
-                if ((aByte & i) != 0)
-                {
-                    crc_value ^= 0x8005;
-                }
-            }
-        }
-        return crc_value;
-    }
 }
diff --git a/src/port/Port.java b/src/port/Port.java
@@ -70,15 +70,19 @@ public boolean open(String serialPortName, int dataBits, int stopBits, int parit
             serialPort = SerialPort.getCommPort(serialPortName);
             serialPort.setComPortParameters(baudRate, dataBits, stopBits, parityBits);
 
-            serialPort.setComPortTimeouts(SerialPort.TIMEOUT_READ_BLOCKING, 1, 0);
+            serialPort.setComPortTimeouts(SerialPort.TIMEOUT_READ_BLOCKING, 0, 0);
 
             stopReading = false;
 
             try
             {
                 return (serialPort.openPort());
             }
-            catch (Exception e){ return false; }
+            catch (Exception e)
+            {
+                e.printStackTrace();
+                return false;
+            }
         }
 
         return false;
@@ -88,6 +92,7 @@ public boolean close()
     {
         boolean isClosed = false;
 
+
         if(null != serialPort)
         {
             isClosed = serialPort.closePort();

diff --git a/src/port/PortReader.java b/src/port/PortReader.java
@@ -1,6 +1,7 @@
 package port;
 
 import classes.Frame;
+import mainwindow.Log;
 
 import java.util.ArrayList;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -13,8 +14,8 @@ public class PortReader extends Port
     private static final byte CHG_BYTE = (byte) 0xA5;
 
     /* maximum is 8 channels where every channel has 1 int value which value it is contained in 4 bytes,
-    so all maximum number of bytes will be 4*8 + one byte of size */
-    private static final byte MAX_FRAME_SIZE = 33;
+    so all maximum number of bytes will be 4*8 + one byte of size + all possible bytes CHG  */
+    private static final byte MAX_FRAME_SIZE = 68;
 
     private static volatile PortReader PortReaderINSTANCE;
 
@@ -70,20 +71,35 @@ private Frame readFrame()
                 {
                     bufferIn = decodePayload(bufferIn);
 
-                    // TODO: validate data
+                    int receivedChecksum = ((bufferIn.get(bufferIn.size()-2) & 0xFF) << 8) | bufferIn.get(bufferIn.size()-1) & 0xFF;
 
-                    try
-                    {
-                        frame = mapToFrame(bufferIn);
+                    bufferIn.remove(bufferIn.size()-1);         // remove from buffer received checksum
+                    bufferIn.remove(bufferIn.size()-1);
 
-                        listening = false;
+                    if ( new CRC16().generateCRC16CCITT(bufferIn) == receivedChecksum)
+                    {
+                        System.out.println("Checksum is right.");
+
+                        try
+                        {
+                            frame = mapToFrame(bufferIn);
+
+                            System.out.println("Buffer mapped to object of Frame type.");
+
+                            listening = false;
+                        }
+                        catch (Exception e)
+                        {
+                            e.printStackTrace();
+                            wasStarted = false;
+                            bufferIn.clear();
+                            cntBytes = 0;
+                        }
                     }
-                    catch (Exception e)
+                    else
                     {
-                        e.printStackTrace();
-                        wasStarted = false;
-                        bufferIn.clear();
-                        cntBytes = 0;
+                        Log.getInstance().log("Received frame is wrong.");
+                        listening = false;
                     }
                 }
                 else
@@ -148,7 +164,7 @@ private Frame mapToFrame(ArrayList<Byte> bytes) throws Exception
 
         for (int i = 0, k = 0; i < numberOfChannels; i++)
         {
-            mappedValues.add( ((bytes.get(++k) & 0xFF) << 24) | ((bytes.get(++k) & 0xFF) << 16) | ((bytes.get(++k) & 0xFF) << 8) | (bytes.get(++k) & 0xFF));
+            mappedValues.add( ((bytes.get(++k) & 0xFF) << 24) | ((bytes.get(++k) & 0xFF) << 16) | ((bytes.get(++k) & 0xFF) << 8) | (bytes.get(++k) & 0xFF) );
         }
 
         return new Frame(mappedValues);
@@ -169,9 +185,13 @@ public void startReading()
 
                     if ( null != frame )
                     {
-                        frameBuffer.put(readFrame());
+                        frameBuffer.put(frame);
                         System.out.println("New frame is added.");
                     }
+                    else
+                    {
+                        System.out.println("Read frame was a null.");
+                    }
                 }
                 catch (InterruptedException e)
                 {