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   1 /*
   2  * Copyright © 2010 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  17  */
  18
  19 package org.altusmetrum.altoslib_11;
  20
  21 import java.text.*;
  22
  23 /*
  24  * Telemetry data contents
  25  */
  26
  27 public abstract class AltosTelemetry implements AltosStateUpdate {
  28         int[]   bytes;
  29
  30         /* All telemetry packets have these fields */
  31         public int rssi() { return AltosConvert.telem_to_rssi(AltosLib.int8(bytes, bytes.length - 3)); }
  32         public int status() { return AltosLib.uint8(bytes, bytes.length - 2); }
  33
  34         /* All telemetry packets report these fields in some form */
  35         public abstract int serial();
  36         public abstract int tick();
  37
  38         /* Mark when we received the packet */
  39         long            received_time;
  40
  41         static boolean cksum(int[] bytes) {
  42                 int     sum = 0x5a;
  43                 for (int i = 1; i < bytes.length - 1; i++)
  44                         sum += bytes[i];
  45                 sum &= 0xff;
  46                 return sum == bytes[bytes.length - 1];
  47         }
  48
  49         public void update_state(AltosState state) {
  50                 state.set_serial(serial());
  51                 if (state.state() == AltosLib.ao_flight_invalid)
  52                         state.set_state(AltosLib.ao_flight_startup);
  53                 state.set_tick(tick());
  54                 state.set_rssi(rssi(), status());
  55                 state.set_received_time(received_time);
  56         }
  57
  58         final static int PKT_APPEND_STATUS_1_CRC_OK             = (1 << 7);
  59         final static int PKT_APPEND_STATUS_1_LQI_MASK           = (0x7f);
  60         final static int PKT_APPEND_STATUS_1_LQI_SHIFT          = 0;
  61
  62         final static int packet_type_TM_sensor = 0x01;
  63         final static int packet_type_Tm_sensor = 0x02;
  64         final static int packet_type_Tn_sensor = 0x03;
  65         final static int packet_type_configuration = 0x04;
  66         final static int packet_type_location = 0x05;
  67         final static int packet_type_satellite = 0x06;
  68         final static int packet_type_companion = 0x07;
  69         final static int packet_type_mega_sensor = 0x08;
  70         final static int packet_type_mega_data = 0x09;
  71         final static int packet_type_metrum_sensor = 0x0a;
  72         final static int packet_type_metrum_data = 0x0b;
  73         final static int packet_type_mini2 = 0x10;
  74         final static int packet_type_mini3 = 0x11;
  75
  76         static AltosTelemetry parse_hex(String hex)  throws ParseException, AltosCRCException {
  77                 AltosTelemetry  telem = null;
  78
  79                 int[] bytes;
  80                 try {
  81                         bytes = AltosLib.hexbytes(hex);
  82                 } catch (NumberFormatException ne) {
  83                         throw new ParseException(ne.getMessage(), 0);
  84                 }
  85
  86                 /* one for length, one for checksum */
  87                 if (bytes[0] != bytes.length - 2)
  88                         throw new ParseException(String.format("invalid length %d != %d\n",
  89                                                                bytes[0],
  90                                                                bytes.length - 2), 0);
  91                 if (!cksum(bytes))
  92                         throw new ParseException(String.format("invalid line \"%s\"", hex), 0);
  93
  94                 /* length, data ..., rssi, status, checksum -- 4 bytes extra */
  95                 switch (bytes.length) {
  96                 case AltosLib.ao_telemetry_standard_len + 4:
  97                         telem = AltosTelemetryStandard.parse_hex(bytes);
  98                         break;
  99                 case AltosLib.ao_telemetry_0_9_len + 4:
 100                         telem = new AltosTelemetryLegacy(bytes);
 101                         break;
 102                 case AltosLib.ao_telemetry_0_8_len + 4:
 103                         telem = new AltosTelemetryLegacy(bytes);
 104                         break;
 105                 default:
 106                         throw new ParseException(String.format("Invalid packet length %d", bytes.length), 0);
 107                 }
 108                 return telem;
 109         }
 110
 111         public static int extend_height(AltosState state, int height_16) {
 112                 double  compare_height;
 113                 int     height = height_16;
 114
 115                 if (state.gps != null && state.gps.alt != AltosLib.MISSING) {
 116                         compare_height = state.gps_height();
 117                 } else {
 118                         compare_height = state.height();
 119                 }
 120
 121                 if (compare_height != AltosLib.MISSING) {
 122                         int     high_bits = (int) Math.floor (compare_height / 65536.0);
 123
 124                         height = (high_bits << 16) | (height_16 & 0xffff);
 125
 126                         if (Math.abs(height + 65536 - compare_height) < Math.abs(height - compare_height))
 127                                 height += 65536;
 128                         else if (Math.abs(height - 65536 - compare_height) < Math.abs(height - compare_height))
 129                                 height -= 65536;
 130                 }
 131                 return height;
 132         }
 133
 134         public AltosTelemetry() {
 135                 this.received_time = System.currentTimeMillis();
 136         }
 137
 138         public AltosTelemetry(int[] bytes) throws AltosCRCException {
 139                 this();
 140                 this.bytes = bytes;
 141                 if ((status() & PKT_APPEND_STATUS_1_CRC_OK) == 0)
 142                         throw new AltosCRCException(rssi());
 143         }
 144
 145         public static AltosTelemetry parse(String line) throws ParseException, AltosCRCException {
 146                 String[] word = line.split("\\s+");
 147                 int i =0;
 148
 149                 if (word[i].equals("CRC") && word[i+1].equals("INVALID")) {
 150                         i += 2;
 151                         AltosParse.word(word[i++], "RSSI");
 152                         throw new AltosCRCException(AltosParse.parse_int(word[i++]));
 153                 }
 154
 155                 AltosTelemetry telem = null;
 156
 157                 if (word[i].equals("TELEM")) {
 158                         telem = parse_hex(word[i+1]);
 159                 } else {
 160                         telem = new AltosTelemetryLegacy(line);
 161                 }
 162                 return telem;
 163         }
 164 }