git.gag.com Git - fw/altos/blob - 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 import java.text.*;
  20
  21 public abstract class AltosTelemetryRecord {
  22
  23         long    received_time;
  24         abstract public AltosRecord update_state(AltosRecord previous);
  25
  26         static boolean cksum(int[] bytes) {
  27                 int     sum = 0x5a;
  28                 for (int i = 1; i < bytes.length - 1; i++)
  29                         sum += bytes[i];
  30                 sum &= 0xff;
  31                 return sum == bytes[bytes.length - 1];
  32         }
  33
  34         final static int PKT_APPEND_STATUS_1_CRC_OK             = (1 << 7);
  35         final static int PKT_APPEND_STATUS_1_LQI_MASK           = (0x7f);
  36         final static int PKT_APPEND_STATUS_1_LQI_SHIFT          = 0;
  37
  38         final static int packet_type_TM_sensor = 0x01;
  39         final static int packet_type_Tm_sensor = 0x02;
  40         final static int packet_type_Tn_sensor = 0x03;
  41         final static int packet_type_configuration = 0x04;
  42         final static int packet_type_location = 0x05;
  43         final static int packet_type_satellite = 0x06;
  44         final static int packet_type_companion = 0x07;
  45
  46         static AltosTelemetryRecord parse_hex(String hex)  throws ParseException, AltosCRCException {
  47                 AltosTelemetryRecord    r;
  48
  49                 int[] bytes;
  50                 try {
  51                         bytes = AltosLib.hexbytes(hex);
  52                 } catch (NumberFormatException ne) {
  53                         throw new ParseException(ne.getMessage(), 0);
  54                 }
  55
  56                 /* one for length, one for checksum */
  57                 if (bytes[0] != bytes.length - 2)
  58                         throw new ParseException(String.format("invalid length %d != %d\n",
  59                                                                bytes[0],
  60                                                                bytes.length - 2), 0);
  61                 if (!cksum(bytes))
  62                         throw new ParseException(String.format("invalid line \"%s\"", hex), 0);
  63
  64                 int     rssi = AltosLib.int8(bytes, bytes.length - 3) / 2 - 74;
  65                 int     status = AltosLib.uint8(bytes, bytes.length - 2);
  66
  67                 if ((status & PKT_APPEND_STATUS_1_CRC_OK) == 0)
  68                         throw new AltosCRCException(rssi);
  69
  70                 /* length, data ..., rssi, status, checksum -- 4 bytes extra */
  71                 switch (bytes.length) {
  72                 case AltosLib.ao_telemetry_standard_len + 4:
  73                         int     type = AltosLib.uint8(bytes, 4 + 1);
  74                         switch (type) {
  75                         case packet_type_TM_sensor:
  76                         case packet_type_Tm_sensor:
  77                         case packet_type_Tn_sensor:
  78                                 r = new AltosTelemetryRecordSensor(bytes, rssi);
  79                                 break;
  80                         case packet_type_configuration:
  81                                 r = new AltosTelemetryRecordConfiguration(bytes);
  82                                 break;
  83                         case packet_type_location:
  84                                 r = new AltosTelemetryRecordLocation(bytes);
  85                                 break;
  86                         case packet_type_satellite:
  87                                 r = new AltosTelemetryRecordSatellite(bytes);
  88                                 break;
  89                         case packet_type_companion:
  90                                 r = new AltosTelemetryRecordCompanion(bytes);
  91                                 break;
  92                         default:
  93                                 r = new AltosTelemetryRecordRaw(bytes);
  94                                 break;
  95                         }
  96                         break;
  97                 case AltosLib.ao_telemetry_0_9_len + 4:
  98                         r = new AltosTelemetryRecordLegacy(bytes, rssi, status);
  99                         break;
 100                 case AltosLib.ao_telemetry_0_8_len + 4:
 101                         r = new AltosTelemetryRecordLegacy(bytes, rssi, status);
 102                         break;
 103                 default:
 104                         throw new ParseException(String.format("Invalid packet length %d", bytes.length), 0);
 105                 }
 106                 r.received_time = System.currentTimeMillis();
 107                 return r;
 108         }
 109
 110         public static AltosTelemetryRecord parse(String line) throws ParseException, AltosCRCException {
 111                 AltosTelemetryRecord    r;
 112
 113                 String[] word = line.split("\\s+");
 114                 int i =0;
 115                 if (word[i].equals("CRC") && word[i+1].equals("INVALID")) {
 116                         i += 2;
 117                         AltosParse.word(word[i++], "RSSI");
 118                         throw new AltosCRCException(AltosParse.parse_int(word[i++]));
 119                 }
 120
 121                 if (word[i].equals("TELEM"))
 122                         r = parse_hex(word[i+1]);
 123                 else
 124                         r = new AltosTelemetryRecordLegacy(line);
 125                 return r;
 126         }
 127 }