3 files changed, 49 insertions, 10 deletions

diff --git a/src/org/traccar/helper/Checksum.java b/src/org/traccar/helper/Checksum.java
index e6b6cd2c8..c156e53f7 100644
--- a/src/org/traccar/helper/Checksum.java
+++ b/src/org/traccar/helper/Checksum.java
@@ -158,13 +158,20 @@ public final class Checksum {
 
     public static String nmea(String msg) {
         int checksum = 0;
-        byte[] bytes = msg.getBytes(Charset.defaultCharset());
-        for (int i = 1; i < msg.length(); i++) {
-            checksum ^= bytes[i];
+        for (byte b : msg.getBytes(Charset.defaultCharset())) {
+            checksum ^= b;
         }
         return String.format("*%02x", checksum).toUpperCase();
     }
 
+    public static String sum(String msg) {
+        byte checksum = 0;
+        for (byte b : msg.getBytes(Charset.defaultCharset())) {
+            checksum += b;
+        }
+        return String.format("%02X", checksum).toUpperCase();
+    }
+
     public static long luhn(long imei) {
         long checksum = 0;
         long remain = imei;
diff --git a/src/org/traccar/helper/ObdDecoder.java b/src/org/traccar/helper/ObdDecoder.java
index 35fa4dc07..c2d9b1841 100644
--- a/src/org/traccar/helper/ObdDecoder.java
+++ b/src/org/traccar/helper/ObdDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 Anton Tananaev (anton.tananaev@gmail.com)
+ * Copyright 2015 - 2016 Anton Tananaev (anton.tananaev@gmail.com)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,8 +25,9 @@ public final class ObdDecoder {
     private ObdDecoder() {
     }
 
-    private static final int MODE_CURRENT = 0x01;
-    private static final int MODE_FREEZE_FRAME = 0x02;
+    public static final int MODE_CURRENT = 0x01;
+    public static final int MODE_FREEZE_FRAME = 0x02;
+    public static final int MODE_CODES = 0x03;
 
     private static final int PID_ENGINE_LOAD = 0x04;
     private static final int PID_COOLANT_TEMPERATURE = 0x05;
@@ -37,11 +38,13 @@ public final class ObdDecoder {
     private static final int PID_FUEL_LEVEL = 0x2F;
     private static final int PID_DISTANCE_CLEARED = 0x31;
 
-    public static Map.Entry<String, Object> decode(int mode, int pid, String value) {
+    public static Map.Entry<String, Object> decode(int mode, String value) {
         switch (mode) {
             case MODE_CURRENT:
             case MODE_FREEZE_FRAME:
-                return decodeData(pid, value);
+                return decodeData(Integer.parseInt(value.substring(0, 2), 16), value.substring(2));
+            case MODE_CODES:
+                return decodeCodes(value);
             default:
                 return null;
         }
@@ -51,6 +54,30 @@ public final class ObdDecoder {
         return new AbstractMap.SimpleEntry<>(key, value);
     }
 
+    private static Map.Entry<String, Object> decodeCodes(String value) {
+        StringBuilder codes = new StringBuilder();
+        for (int i = 0; i < value.length() / 4; i++) {
+            int numValue = Integer.parseInt(value.substring(i * 4, (i + 1) * 4), 16);
+            codes.append(',');
+            switch (numValue >> 14) {
+                case 1:
+                    codes.append('C');
+                    break;
+                case 2:
+                    codes.append('B');
+                    break;
+                case 3:
+                    codes.append('U');
+                    break;
+                default:
+                    codes.append('P');
+                    break;
+            }
+            codes.append(String.format("%04X", numValue & 0x3FFF));
+        }
+        return createEntry("dtcs", codes.toString().replaceFirst(",", ""));
+    }
+
     private static Map.Entry<String, Object> decodeData(int pid, String value) {
         int intValue = Integer.parseInt(value, 16);
         switch (pid) {
@@ -69,7 +96,7 @@ public final class ObdDecoder {
             case PID_FUEL_LEVEL:
                 return createEntry(Event.KEY_FUEL, intValue * 100 / 255);
             case PID_DISTANCE_CLEARED:
-                return createEntry(Event.KEY_FUEL, intValue);
+                return createEntry("cleared-distance", intValue);
             default:
                 return null;
         }
diff --git a/src/org/traccar/helper/Parser.java b/src/org/traccar/helper/Parser.java
index a3f118df0..dcea1c8f7 100644
--- a/src/org/traccar/helper/Parser.java
+++ b/src/org/traccar/helper/Parser.java
@@ -37,12 +37,17 @@ public class Parser {
         return matcher.find();
     }
 
+    public void skip(int number) {
+        position += number;
+    }
+
     public boolean hasNext() {
         return hasNext(1);
     }
 
     public boolean hasNext(int number) {
-        if (matcher.group(position) != null) {
+        String value = matcher.group(position);
+        if (value != null && !value.isEmpty()) {
             return true;
         } else {
             position += number;