git.gag.com Git - fw/altos/blob - altoslib/src/org/altusmetrum/AltosLib/AltosTelemetryRecord.java

   1 /*
   2  * Copyright © 2011 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; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 package org.altusmetrum.AltosLib;
  19
  20 public abstract class AltosTelemetryRecord {
  21
  22         long    received_time;
  23         abstract public AltosRecord update_state(AltosRecord previous);
  24
  25         static boolean cksum(int[] bytes) {
  26                 int     sum = 0x5a;
  27                 for (int i = 1; i < bytes.length - 1; i++)
  28                         sum += bytes[i];
  29                 sum &= 0xff;
  30                 return sum == bytes[bytes.length - 1];
  31         }
  32
  33         final static int PKT_APPEND_STATUS_1_CRC_OK             = (1 << 7);
  34         final static int PKT_APPEND_STATUS_1_LQI_MASK           = (0x7f);
  35         final static int PKT_APPEND_STATUS_1_LQI_SHIFT          = 0;
  36
  37         final static int packet_type_TM_sensor = 0x01;
  38         final static int packet_type_Tm_sensor = 0x02;
  39         final static int packet_type_Tn_sensor = 0x03;
  40         final static int packet_type_configuration = 0x04;
  41         final static int packet_type_location = 0x05;
  42         final static int packet_type_satellite = 0x06;
  43         final static int packet_type_companion = 0x07;
  44
  45         static AltosTelemetryRecord parse_hex(String hex)  throws ParseException, AltosCRCException {
  46                 AltosTelemetryRecord    r;
  47
  48                 int[] bytes;
  49                 try {
  50                         bytes = Altos.hexbytes(hex);
  51                 } catch (NumberFormatException ne) {
  52                         throw new ParseException(ne.getMessage(), 0);
  53                 }
  54
  55                 /* one for length, one for checksum */
  56                 if (bytes[0] != bytes.length - 2)
  57                         throw new ParseException(String.format("invalid length %d != %d\n",
  58                                                                bytes[0],
  59                                                                bytes.length - 2), 0);
  60                 if (!cksum(bytes))
  61                         throw new ParseException(String.format("invalid line \"%s\"", hex), 0);
  62
  63                 int     rssi = Altos.int8(bytes, bytes.length - 3) / 2 - 74;
  64                 int     status = Altos.uint8(bytes, bytes.length - 2);
  65
  66                 if ((status & PKT_APPEND_STATUS_1_CRC_OK) == 0)
  67                         throw new AltosCRCException(rssi);
  68
  69                 /* length, data ..., rssi, status, checksum -- 4 bytes extra */
  70                 switch (bytes.length) {
  71                 case Altos.ao_telemetry_standard_len + 4:
  72                         int     type = Altos.uint8(bytes, 4 + 1);
  73                         switch (type) {
  74                         case packet_type_TM_sensor:
  75                         case packet_type_Tm_sensor:
  76                         case packet_type_Tn_sensor:
  77                                 r = new AltosTelemetryRecordSensor(bytes, rssi);
  78                                 break;
  79                         case packet_type_configuration:
  80                                 r = new AltosTelemetryRecordConfiguration(bytes);
  81                                 break;
  82                         case packet_type_location:
  83                                 r = new AltosTelemetryRecordLocation(bytes);
  84                                 break;
  85                         case packet_type_satellite:
  86                                 r = new AltosTelemetryRecordSatellite(bytes);
  87                                 break;
  88                         case packet_type_companion:
  89                                 r = new AltosTelemetryRecordCompanion(bytes);
  90                                 break;
  91                         default:
  92                                 r = new AltosTelemetryRecordRaw(bytes);
  93                                 break;
  94                         }
  95                         break;
  96                 case Altos.ao_telemetry_0_9_len + 4:
  97                         r = new AltosTelemetryRecordLegacy(bytes, rssi, status);
  98                         break;
  99                 case Altos.ao_telemetry_0_8_len + 4:
 100                         r = new AltosTelemetryRecordLegacy(bytes, rssi, status);
 101                         break;
 102                 default:
 103                         throw new ParseException(String.format("Invalid packet length %d", bytes.length), 0);
 104                 }
 105                 r.received_time = System.currentTimeMillis();
 106                 return r;
 107         }
 108
 109         public static AltosTelemetryRecord parse(String line) throws ParseException, AltosCRCException {
 110                 AltosTelemetryRecord    r;
 111
 112                 String[] word = line.split("\\s+");
 113                 int i =0;
 114                 if (word[i].equals("CRC") && word[i+1].equals("INVALID")) {
 115                         i += 2;
 116                         AltosParse.word(word[i++], "RSSI");
 117                         throw new AltosCRCException(AltosParse.parse_int(word[i++]));
 118                 }
 119
 120                 if (word[i].equals("TELEM"))
 121                         r = parse_hex(word[i+1]);
 122                 else
 123                         r = new AltosTelemetryRecordLegacy(line);
 124                 return r;
 125         }
 126 }