/* * 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. * 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() { } 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; private static final int PID_ENGINE_RPM = 0x0C; private static final int PID_VEHICLE_SPEED = 0x0D; private static final int PID_THROTTLE_POSITION = 0x11; private static final int PID_MIL_DISTANCE = 0x21; 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, String value) { switch (mode) { case MODE_CURRENT: case MODE_FREEZE_FRAME: return decodeData(Integer.parseInt(value.substring(0, 2), 16), value.substring(2)); 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); } 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) { case PID_ENGINE_LOAD: return createEntry("engineLoad", intValue * 100 / 255); case PID_COOLANT_TEMPERATURE: return createEntry("coolantTemperature", intValue - 40); case PID_ENGINE_RPM: return createEntry(Position.KEY_RPM, intValue / 4); case PID_VEHICLE_SPEED: return createEntry(Position.KEY_OBD_SPEED, intValue); case PID_THROTTLE_POSITION: return createEntry("throttle", intValue * 100 / 255); case PID_MIL_DISTANCE: return createEntry("milDistance", intValue); case PID_FUEL_LEVEL: return createEntry(Position.KEY_FUEL, intValue * 100 / 255); case PID_DISTANCE_CLEARED: return createEntry("clearedDistance", intValue); default: return null; } } }