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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.car.obd2;
     18 
     19 import com.android.car.obd2.commands.AmbientAirTemperature;
     20 import com.android.car.obd2.commands.CalculatedEngineLoad;
     21 import com.android.car.obd2.commands.EngineCoolantTemperature;
     22 import com.android.car.obd2.commands.EngineOilTemperature;
     23 import com.android.car.obd2.commands.EngineRuntime;
     24 import com.android.car.obd2.commands.FuelGaugePressure;
     25 import com.android.car.obd2.commands.FuelSystemStatus;
     26 import com.android.car.obd2.commands.FuelTankLevel;
     27 import com.android.car.obd2.commands.FuelTrimCommand.Bank1LongTermFuelTrimCommand;
     28 import com.android.car.obd2.commands.FuelTrimCommand.Bank1ShortTermFuelTrimCommand;
     29 import com.android.car.obd2.commands.FuelTrimCommand.Bank2LongTermFuelTrimCommand;
     30 import com.android.car.obd2.commands.FuelTrimCommand.Bank2ShortTermFuelTrimCommand;
     31 import com.android.car.obd2.commands.RPM;
     32 import com.android.car.obd2.commands.Speed;
     33 import com.android.car.obd2.commands.ThrottlePosition;
     34 import java.io.IOException;
     35 import java.util.HashMap;
     36 import java.util.Objects;
     37 import java.util.Optional;
     38 import java.util.Set;
     39 
     40 /**
     41  * Base class of OBD2 command objects that query a "vehicle" and return an individual data point
     42  * represented as a Java type.
     43  *
     44  * @param  The Java type that represents the value of this command's output.
     45  */
     46 public abstract class Obd2Command<ValueType> {
     47 
     48     /**
     49      * Abstract representation of an object whose job it is to receive the bytes read from the OBD2
     50      * connection and return a Java representation of a command's value.
     51      *
     52      * @param 
     53      */
     54     public interface OutputSemanticHandler<ValueType> {
     55         int getPid();
     56 
     57         Optional<ValueType> consume(IntegerArrayStream data);
     58     }
     59 
     60     public static final int LIVE_FRAME = 1;
     61     public static final int FREEZE_FRAME = 2;
     62 
     63     private static final HashMap<Integer, OutputSemanticHandler<Integer>>
     64             SUPPORTED_INTEGER_COMMANDS = new HashMap<>();
     65     private static final HashMap<Integer, OutputSemanticHandler<Float>> SUPPORTED_FLOAT_COMMANDS =
     66             new HashMap<>();
     67 
     68     private static void addSupportedIntegerCommands(
     69             OutputSemanticHandler<Integer>... integerOutputSemanticHandlers) {
     70         for (OutputSemanticHandler<Integer> integerOutputSemanticHandler :
     71                 integerOutputSemanticHandlers) {
     72             SUPPORTED_INTEGER_COMMANDS.put(
     73                     integerOutputSemanticHandler.getPid(), integerOutputSemanticHandler);
     74         }
     75     }
     76 
     77     private static void addSupportedFloatCommands(
     78             OutputSemanticHandler<Float>... floatOutputSemanticHandlers) {
     79         for (OutputSemanticHandler<Float> floatOutputSemanticHandler :
     80                 floatOutputSemanticHandlers) {
     81             SUPPORTED_FLOAT_COMMANDS.put(
     82                     floatOutputSemanticHandler.getPid(), floatOutputSemanticHandler);
     83         }
     84     }
     85 
     86     public static Set<Integer> getSupportedIntegerCommands() {
     87         return SUPPORTED_INTEGER_COMMANDS.keySet();
     88     }
     89 
     90     public static Set<Integer> getSupportedFloatCommands() {
     91         return SUPPORTED_FLOAT_COMMANDS.keySet();
     92     }
     93 
     94     public static OutputSemanticHandler<Integer> getIntegerCommand(int pid) {
     95         return SUPPORTED_INTEGER_COMMANDS.get(pid);
     96     }
     97 
     98     public static OutputSemanticHandler<Float> getFloatCommand(int pid) {
     99         return SUPPORTED_FLOAT_COMMANDS.get(pid);
    100     }
    101 
    102     static {
    103         addSupportedFloatCommands(
    104                 new AmbientAirTemperature(),
    105                 new CalculatedEngineLoad(),
    106                 new FuelTankLevel(),
    107                 new Bank2ShortTermFuelTrimCommand(),
    108                 new Bank2LongTermFuelTrimCommand(),
    109                 new Bank1LongTermFuelTrimCommand(),
    110                 new Bank1ShortTermFuelTrimCommand(),
    111                 new ThrottlePosition());
    112         addSupportedIntegerCommands(
    113                 new EngineOilTemperature(),
    114                 new EngineCoolantTemperature(),
    115                 new FuelGaugePressure(),
    116                 new FuelSystemStatus(),
    117                 new RPM(),
    118                 new EngineRuntime(),
    119                 new Speed());
    120     }
    121 
    122     protected final int mMode;
    123     protected final OutputSemanticHandler<ValueType> mSemanticHandler;
    124 
    125     Obd2Command(int mode, OutputSemanticHandler<ValueType> semanticHandler) {
    126         mMode = mode;
    127         mSemanticHandler = Objects.requireNonNull(semanticHandler);
    128     }
    129 
    130     public abstract Optional<ValueType> run(Obd2Connection connection) throws Exception;
    131 
    132     public int getPid() {
    133         return mSemanticHandler.getPid();
    134     }
    135 
    136     public static final <T> LiveFrameCommand<T> getLiveFrameCommand(OutputSemanticHandler handler) {
    137         return new LiveFrameCommand<>(handler);
    138     }
    139 
    140     public static final <T> FreezeFrameCommand<T> getFreezeFrameCommand(
    141             OutputSemanticHandler handler, int frameId) {
    142         return new FreezeFrameCommand<>(handler, frameId);
    143     }
    144 
    145     /**
    146      * An OBD2 command that returns live frame data.
    147      *
    148      * @param  The Java type that represents the command's result type.
    149      */
    150     public static class LiveFrameCommand<ValueType> extends Obd2Command<ValueType> {
    151         private static final int RESPONSE_MARKER = 0x41;
    152 
    153         LiveFrameCommand(OutputSemanticHandler<ValueType> semanticHandler) {
    154             super(LIVE_FRAME, semanticHandler);
    155         }
    156 
    157         public Optional<ValueType> run(Obd2Connection connection)
    158                 throws IOException, InterruptedException {
    159             String command = String.format("%02X%02X", mMode, mSemanticHandler.getPid());
    160             int[] data = connection.run(command);
    161             IntegerArrayStream stream = new IntegerArrayStream(data);
    162             if (stream.expect(RESPONSE_MARKER, mSemanticHandler.getPid())) {
    163                 return mSemanticHandler.consume(stream);
    164             }
    165             return Optional.empty();
    166         }
    167     }
    168 
    169     /**
    170      * An OBD2 command that returns freeze frame data.
    171      *
    172      * @param  The Java type that represents the command's result type.
    173      */
    174     public static class FreezeFrameCommand<ValueType> extends Obd2Command<ValueType> {
    175         private static final int RESPONSE_MARKER = 0x2;
    176 
    177         private int mFrameId;
    178 
    179         FreezeFrameCommand(OutputSemanticHandler<ValueType> semanticHandler, int frameId) {
    180             super(FREEZE_FRAME, semanticHandler);
    181             mFrameId = frameId;
    182         }
    183 
    184         public Optional<ValueType> run(Obd2Connection connection)
    185                 throws IOException, InterruptedException {
    186             String command =
    187                     String.format("%02X%02X %02X", mMode, mSemanticHandler.getPid(), mFrameId);
    188             int[] data = connection.run(command);
    189             IntegerArrayStream stream = new IntegerArrayStream(data);
    190             if (stream.expect(RESPONSE_MARKER, mSemanticHandler.getPid(), mFrameId)) {
    191                 return mSemanticHandler.consume(stream);
    192             }
    193             return Optional.empty();
    194         }
    195     }
    196 }
    197