aboutsummaryrefslogtreecommitdiff
path: root/src/org/traccar/protocol/AtrackProtocolDecoder.java
blob: 5ccd8ed30f4d2cd6a5c9b375c24218eacdb78809 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/*
 * Copyright 2013 - 2014 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.protocol;

import java.net.SocketAddress;
import java.nio.charset.Charset;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;

import org.traccar.BaseProtocolDecoder;
import org.traccar.model.Event;
import org.traccar.model.Position;

public class AtrackProtocolDecoder extends BaseProtocolDecoder {

    public AtrackProtocolDecoder(String protocol) {
        super(protocol);
    }

    private static final int MSG_HEARTBEAT = 0x1A;
    private static final int MSG_DATA = 0x10;

    private static final int MIN_DATA_LENGTH = 40;

    private static void sendResponse(Channel channel, SocketAddress remoteAddress, long rawId, int index) {
        if (channel != null) {
            ChannelBuffer response = ChannelBuffers.directBuffer(12);
            response.writeShort(0xfe02);
            response.writeLong(rawId);
            response.writeShort(index);
            channel.write(response, remoteAddress);
        }
    }
    
    private static String readString(ChannelBuffer buf) {
        
        String result = null;
        int length = 0;
        while (buf.getByte(buf.readerIndex() + length) != 0) {
            length += 1;
        }
        if (length != 0) {
            result = buf.toString(buf.readerIndex(), length, Charset.defaultCharset());
            buf.skipBytes(length);
        }
        buf.readByte();
        
        return result;
    }
    
    @Override
    protected Object decode(
            ChannelHandlerContext ctx, Channel channel, SocketAddress remoteAddress, Object msg)
            throws Exception {

        ChannelBuffer buf = (ChannelBuffer) msg;

        // Keep alive message
        if (buf.getUnsignedShort(buf.readerIndex()) == 0xfe02) {
            if (channel != null) {
                channel.write(buf, remoteAddress);
            }
            return null;
        }
        
        buf.skipBytes(2); // prefix
        buf.readUnsignedShort(); // checksum
        buf.readUnsignedShort(); // length
        int index = buf.readUnsignedShort();

        // Get device id
        long id = buf.readLong();
        if (!identify(String.valueOf(id))) {
            return null;
        }

        // Send acknowledgement
        sendResponse(channel, remoteAddress, id, index);

        List<Position> positions = new LinkedList<Position>();

        while (buf.readableBytes() >= MIN_DATA_LENGTH) {

            // Create new position
            Position position = new Position();
            position.setDeviceId(getDeviceId());
            position.setProtocol(getProtocol());

            // Date and time
            position.setTime(new Date(buf.readUnsignedInt() * 1000)); // gps time
            buf.readUnsignedInt(); // rtc time
            buf.readUnsignedInt(); // send time

            // Coordinates
            position.setValid(true);
            position.setLongitude(buf.readInt() * 0.000001);
            position.setLatitude(buf.readInt() * 0.000001);

            // Course
            position.setCourse(buf.readUnsignedShort());

            // Report type
            position.set("type", buf.readUnsignedByte());

            // Odometer
            position.set(Event.KEY_ODOMETER, buf.readUnsignedInt() * 0.1);

            // Accuracy
            position.set(Event.KEY_HDOP, buf.readUnsignedShort() * 0.1);

            // Input
            position.set(Event.KEY_INPUT, buf.readUnsignedByte());

            // Speed
            position.setSpeed(buf.readUnsignedShort() * 0.539957);

            // Output
            position.set(Event.KEY_OUTPUT, buf.readUnsignedByte());

            // ADC
            position.set("adc", buf.readUnsignedShort() * 0.001);

            // Driver
            position.set("driver", readString(buf));

            // Temperature
            position.set("temperature1", buf.readShort() * 0.1);
            position.set("temperature2", buf.readShort() * 0.1);

            // Text Message
            position.set("message", readString(buf));

            // With AT$FORM Command you can extend atrack protocol.
            // For example adding AT$FORM %FC /Fuel used you can add the line in this position:
            // position.set("fuelused", buf.readUnsignedInt() * 0.1);
            positions.add(position);
        }

        return positions;
    }

}