1 files changed, 36 insertions, 18 deletions
diff --git a/src/main/java/org/traccar/protocol/Gt06ProtocolDecoder.java b/src/main/java/org/traccar/protocol/Gt06ProtocolDecoder.java
index 0fc94d15f..2c2ca7365 100644
--- a/src/main/java/org/traccar/protocol/Gt06ProtocolDecoder.java
+++ b/src/main/java/org/traccar/protocol/Gt06ProtocolDecoder.java
@@ -210,6 +210,11 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
     }
 
     public static boolean decodeGps(Position position, ByteBuf buf, boolean hasLength, TimeZone timezone) {
+        return decodeGps(position, buf, hasLength, true, true, timezone);
+    }
+
+    public static boolean decodeGps(Position position, ByteBuf buf, boolean hasLength, boolean hasSatellites,
+            boolean hasSpeed, TimeZone timezone) {
 
         DateBuilder dateBuilder = new DateBuilder(timezone)
                 .setDate(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte())
@@ -220,19 +225,14 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             return false;
         }
 
-        position.set(Position.KEY_SATELLITES, BitUtil.to(buf.readUnsignedByte(), 4));
-
-        decodeLocation(position, buf, true);
-
-        return true;
-    }
-
-    private static void decodeLocation(Position position, ByteBuf buf, boolean withSpeed) {
+        if (hasSatellites) {
+            position.set(Position.KEY_SATELLITES, BitUtil.to(buf.readUnsignedByte(), 4));
+        }
 
         double latitude = buf.readUnsignedInt() / 60.0 / 30000.0;
         double longitude = buf.readUnsignedInt() / 60.0 / 30000.0;
 
-        if (withSpeed) {
+        if (hasSpeed) {
             position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte()));
         }
 
@@ -254,6 +254,7 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             position.set(Position.KEY_IGNITION, BitUtil.check(flags, 15));
         }
 
+        return true;
     }
 
     private boolean decodeLbs(Position position, ByteBuf buf, boolean hasLength) {
@@ -788,19 +789,19 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
             }
 
         } else if (type == MSG_ALARM) {
-            DateBuilder dateBuilder = new DateBuilder(deviceSession.getTimeZone())
-                    .setDate(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte())
-                    .setTime(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte());
-            if (dataLength == 7) {
-                getLastLocation(position, dateBuilder.getDate());
+            boolean extendedAlarm = dataLength > 7;
+            if (extendedAlarm) {
+                decodeGps(position, buf, false, false, false, deviceSession.getTimeZone());
             } else {
-                position.setTime(dateBuilder.getDate());
-                decodeLocation(position, buf, false);
+                DateBuilder dateBuilder = new DateBuilder(deviceSession.getTimeZone())
+                        .setDate(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte())
+                        .setTime(buf.readUnsignedByte(), buf.readUnsignedByte(), buf.readUnsignedByte());
+                getLastLocation(position, dateBuilder.getDate());
             }
             short alarmType = buf.readUnsignedByte();
             switch (alarmType) {
                 case 0x01:
-                    position.set(Position.KEY_ALARM, dataLength == 7 ? Position.ALARM_GENERAL : Position.ALARM_SOS);
+                    position.set(Position.KEY_ALARM, extendedAlarm ? Position.ALARM_SOS : Position.ALARM_GENERAL);
                     break;
                 case 0x80:
                     position.set(Position.KEY_ALARM, Position.ALARM_VIBRATION);
@@ -1121,7 +1122,24 @@ public class Gt06ProtocolDecoder extends BaseProtocolDecoder {
                     position.setTime(new Date(buf.readUnsignedInt() * 1000));
                     position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
                     position.setAltitude(buf.readShort());
-                    decodeLocation(position, buf, true);
+
+                    double latitude = buf.readUnsignedInt() / 60.0 / 30000.0;
+                    double longitude = buf.readUnsignedInt() / 60.0 / 30000.0;
+                    position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedByte()));
+
+                    int flags = buf.readUnsignedShort();
+                    position.setCourse(BitUtil.to(flags, 10));
+                    position.setValid(BitUtil.check(flags, 12));
+
+                    if (!BitUtil.check(flags, 10)) {
+                        latitude = -latitude;
+                    }
+                    if (BitUtil.check(flags, 11)) {
+                        longitude = -longitude;
+                    }
+
+                    position.setLatitude(latitude);
+                    position.setLongitude(longitude);
                     break;
                 case 0x34:
                     position.set(Position.KEY_EVENT, buf.readUnsignedByte());