1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/helper/ObdDecoder.java b/src/main/java/org/traccar/helper/ObdDecoder.java
new file mode 100644
index 000000000..1bdcce352
--- /dev/null
+++ b/src/main/java/org/traccar/helper/ObdDecoder.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015 - 2018 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.helper;
+
+import org.traccar.model.Position;
+
+import java.util.AbstractMap;
+import java.util.Map;
+
+public final class ObdDecoder {
+
+    private ObdDecoder() {
+    }
+
+    private static final int MODE_CURRENT = 0x01;
+    private static final int MODE_FREEZE_FRAME = 0x02;
+    private static final int MODE_CODES = 0x03;
+
+    public static Map.Entry<String, Object> decode(int mode, String value) {
+        switch (mode) {
+            case MODE_CURRENT:
+            case MODE_FREEZE_FRAME:
+                return decodeData(
+                        Integer.parseInt(value.substring(0, 2), 16),
+                        Integer.parseInt(value.substring(2), 16), true);
+            case MODE_CODES:
+                return decodeCodes(value);
+            default:
+                return null;
+        }
+    }
+
+    private static Map.Entry<String, Object> createEntry(String key, Object value) {
+        return new AbstractMap.SimpleEntry<>(key, value);
+    }
+
+    public 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));
+        }
+        if (codes.length() > 0) {
+            return createEntry(Position.KEY_DTCS, codes.toString().trim());
+        } else {
+            return null;
+        }
+    }
+
+    public static Map.Entry<String, Object> decodeData(int pid, int value, boolean convert) {
+        switch (pid) {
+            case 0x04:
+                return createEntry(Position.KEY_ENGINE_LOAD, convert ? value * 100 / 255 : value);
+            case 0x05:
+                return createEntry(Position.KEY_COOLANT_TEMP, convert ? value - 40 : value);
+            case 0x0B:
+                return createEntry("mapIntake", value);
+            case 0x0C:
+                return createEntry(Position.KEY_RPM, convert ? value / 4 : value);
+            case 0x0D:
+                return createEntry(Position.KEY_OBD_SPEED, value);
+            case 0x0F:
+                return createEntry("intakeTemp", convert ? value - 40 : value);
+            case 0x11:
+                return createEntry(Position.KEY_THROTTLE, convert ? value * 100 / 255 : value);
+            case 0x21:
+                return createEntry("milDistance", value);
+            case 0x2F:
+                return createEntry(Position.KEY_FUEL_LEVEL, convert ? value * 100 / 255 : value);
+            case 0x31:
+                return createEntry("clearedDistance", value);
+            default:
+                return null;
+        }
+    }
+
+}