/* * Copyright © 2011 Keith Packard * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ package org.altusmetrum.AltosLib; public abstract class AltosTelemetryRecord { long received_time; abstract public AltosRecord update_state(AltosRecord previous); static boolean cksum(int[] bytes) { int sum = 0x5a; for (int i = 1; i < bytes.length - 1; i++) sum += bytes[i]; sum &= 0xff; return sum == bytes[bytes.length - 1]; } final static int PKT_APPEND_STATUS_1_CRC_OK = (1 << 7); final static int PKT_APPEND_STATUS_1_LQI_MASK = (0x7f); final static int PKT_APPEND_STATUS_1_LQI_SHIFT = 0; final static int packet_type_TM_sensor = 0x01; final static int packet_type_Tm_sensor = 0x02; final static int packet_type_Tn_sensor = 0x03; final static int packet_type_configuration = 0x04; final static int packet_type_location = 0x05; final static int packet_type_satellite = 0x06; final static int packet_type_companion = 0x07; static AltosTelemetryRecord parse_hex(String hex) throws ParseException, AltosCRCException { AltosTelemetryRecord r; int[] bytes; try { bytes = Altos.hexbytes(hex); } catch (NumberFormatException ne) { throw new ParseException(ne.getMessage(), 0); } /* one for length, one for checksum */ if (bytes[0] != bytes.length - 2) throw new ParseException(String.format("invalid length %d != %d\n", bytes[0], bytes.length - 2), 0); if (!cksum(bytes)) throw new ParseException(String.format("invalid line \"%s\"", hex), 0); int rssi = Altos.int8(bytes, bytes.length - 3) / 2 - 74; int status = Altos.uint8(bytes, bytes.length - 2); if ((status & PKT_APPEND_STATUS_1_CRC_OK) == 0) throw new AltosCRCException(rssi); /* length, data ..., rssi, status, checksum -- 4 bytes extra */ switch (bytes.length) { case Altos.ao_telemetry_standard_len + 4: int type = Altos.uint8(bytes, 4 + 1); switch (type) { case packet_type_TM_sensor: case packet_type_Tm_sensor: case packet_type_Tn_sensor: r = new AltosTelemetryRecordSensor(bytes, rssi); break; case packet_type_configuration: r = new AltosTelemetryRecordConfiguration(bytes); break; case packet_type_location: r = new AltosTelemetryRecordLocation(bytes); break; case packet_type_satellite: r = new AltosTelemetryRecordSatellite(bytes); break; case packet_type_companion: r = new AltosTelemetryRecordCompanion(bytes); break; default: r = new AltosTelemetryRecordRaw(bytes); break; } break; case Altos.ao_telemetry_0_9_len + 4: r = new AltosTelemetryRecordLegacy(bytes, rssi, status); break; case Altos.ao_telemetry_0_8_len + 4: r = new AltosTelemetryRecordLegacy(bytes, rssi, status); break; default: throw new ParseException(String.format("Invalid packet length %d", bytes.length), 0); } r.received_time = System.currentTimeMillis(); return r; } public static AltosTelemetryRecord parse(String line) throws ParseException, AltosCRCException { AltosTelemetryRecord r; String[] word = line.split("\\s+"); int i =0; if (word[i].equals("CRC") && word[i+1].equals("INVALID")) { i += 2; AltosParse.word(word[i++], "RSSI"); throw new AltosCRCException(AltosParse.parse_int(word[i++])); } if (word[i].equals("TELEM")) r = parse_hex(word[i+1]); else r = new AltosTelemetryRecordLegacy(line); return r; } }