diff options
Diffstat (limited to 'altoslib/AltosTelemetryRecord.java')
| -rw-r--r-- | altoslib/AltosTelemetryRecord.java | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/altoslib/AltosTelemetryRecord.java b/altoslib/AltosTelemetryRecord.java new file mode 100644 index 00000000..367c148d --- /dev/null +++ b/altoslib/AltosTelemetryRecord.java @@ -0,0 +1,126 @@ +/* + * Copyright © 2011 Keith Packard <keithp@keithp.com> + * + * 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; + } +} |