/* * Copyright 2015 - 2020 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), Long.parseLong(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, long 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; } } }