org.ka2ddo.aprs

Class TelemetryMessage

java.lang.Object

org.ka2ddo.ax25.AX25Message

org.ka2ddo.aprs.Message

org.ka2ddo.aprs.TelemetryMessage

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.lang.Comparable<AX25Message>, CommentedMessage, SendableMessage

public class TelemetryMessage
extends Message
implements SendableMessage

This class contains a decoded APRS telemetry message (APRS protocol specification chapter 13).

Author:

Andrew Pavlin, KA2DDO

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.ka2ddo.ax25.AX25Message

AX25Message.Precedence

Field Summary

Fields

Modifier and Type	Field and Description
float[]	analogValues A 5-element array of the 5 non-boolean analog values in the telemetry message.
int	bitmask A bitmask containing the 8 boolean digits from the telemetry message.
static int	MIC Constant representing the decoded representation of the "MIC" sequence "number".
int	sequenceNum The extracted sequence number of the telemetry data.

Fields inherited from class org.ka2ddo.aprs.Message

appendCR, APRS_AND_OPENTRAC_AND_RAW, APRS_AND_RAW, comment, msgType, S_PERMANENT, S_PERMANENT_UC, symbolCode, symTableId

Fields inherited from class org.ka2ddo.ax25.AX25Message

APRS_AND_OPENTRAC, ax25Frame, extensions, invalid, originatingCallsign, originatingDest, PERMANENT, rcptTime, thirdParty, timestamp, UTC

Constructor Summary

Constructors

Constructor and Description
TelemetryMessage() Create a TelemetryMessage suitable for transmission to another station.
TelemetryMessage(byte[] body, int offset, java.lang.String tp, long rcvTimestamp) Constructor for a TelemetryMessage from an AX25Frame.
TelemetryMessage(PositionMessage pm, int startPos, int endPos) Construct a TelemetryMessage based on Base91 Telemetry data extracted from a PositionMessage's comment, per the proposed extension documented in http://he.fi/doc/aprs-base91-comment-telemetry.txt.

Method Summary

Modifier and Type	Method and Description
boolean	bodyEquals(AX25Message o) Compare the contents of the body of the message, reporting if they match.
void	disableForTransmit() Specify that message should no longer be transmitted.
java.lang.String	getBase91Encoding() Encode this telemetry data in the format for base-91 appending to the comment of an APRS PositionReport, per http://he.fi/doc/aprs-base91-comment-telemetry.txt.
byte[]	getBody(boolean countTransmission, ProtocolFamily protocolId, AX25Frame frame) Get an instance of this message, suitable for transmitting.
boolean	isEnabled() Test if message should still be transmitted.
java.lang.String	paramString() Descriptive text about this message, to be included in the toString() method's response.

Methods inherited from class org.ka2ddo.aprs.Message

compareTo, decodeDatestamp, decodeHurricaneParams, decodeTimestamp, decodeWeatherParams, decodeWeatherParams, dup, encodeTimestamp, extractComment, extractComment, extractSymbol, formatBody, getComment, getExtensionString, getMsgType, getPrecedence, getProtocols, getSymbolCode, getSymTableId, hasWeather, inferSymbol, isAppendCR, isSymbolInferred, looksLikeLongFormatLatitude, setAppendCR, setComment, setSymbolCode, setSymTableId, toString

Methods inherited from class org.ka2ddo.ax25.AX25Message

equals, extractSource, getAx25Frame, getExtension, getFirstDigipeat, getLastDigipeat, getNthDigipeat, getOriginalDestination, getOriginalSource, getOriginatingCallsign, getOriginatingDest, getRcptTime, getReadOnlyExtensionMap, getTimestamp, hashCode, hasPosition, hasThisFirstDigi, indexOf, indexOf, isDirect, isInvalid, isRf, onlyDigits, onlyDigits, onlyDigitsOrMinus, onlyDigitsOrPeriod, onlyDigitsOrSpace, onlyDigitsPlus, onlyPeriods, setAx25Frame, setInvalid, setOriginatingCallsign, setRcptTime, setTimestamp, split, storeExtension

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.ka2ddo.ax25.SendableMessage

dup

Field Detail

MIC

public static final int MIC

Constant representing the decoded representation of the "MIC" sequence "number".

See Also:

Constant Field Values

sequenceNum

public int sequenceNum

The extracted sequence number of the telemetry data.

analogValues

public float[] analogValues

A 5-element array of the 5 non-boolean analog values in the telemetry message.

bitmask

public int bitmask

A bitmask containing the 8 boolean digits from the telemetry message.

Constructor Detail

TelemetryMessage

public TelemetryMessage()

Create a TelemetryMessage suitable for transmission to another station.

TelemetryMessage

public TelemetryMessage(byte[] body,
                        int offset,
                        java.lang.String tp,
                        long rcvTimestamp)

Constructor for a TelemetryMessage from an AX25Frame. The caller is responsible for ensuring the byte array contains a TelemetryMessage before using this class to decode it.

Parameters:

body - byte array containing the message

offset - index into the byte array where the telemetry message text starts

tp - String of third-party routing data (may be null)

rcvTimestamp - time in Java milliseconds since Jan 1 1970 UTC when this message was received

TelemetryMessage

public TelemetryMessage(PositionMessage pm,
                        int startPos,
                        int endPos)

Construct a TelemetryMessage based on Base91 Telemetry data extracted from a PositionMessage's comment, per the proposed extension documented in http://he.fi/doc/aprs-base91-comment-telemetry.txt.

Parameters:

pm - PositionMessage containing the base-91 telemetry data

startPos - index into the PositionMessage's comment where the telemetry data starts (after the '|' character)

endPos - index into the PositionMessage's comment where the telemetry data ends (the closing '|' character)

Method Detail

paramString

public java.lang.String paramString()

Descriptive text about this message, to be included in the toString() method's response. This method may be overridden, and the override may concatenate the results of the superclass's paramString) method with additional text of its own.

Overrides:

paramString in class Message

Returns:

String describing the contents of this message

See Also:

Message.toString(), Message.getComment()

getBase91Encoding

public java.lang.String getBase91Encoding()
                                   throws java.lang.IllegalArgumentException

Encode this telemetry data in the format for base-91 appending to the comment of an APRS PositionReport, per http://he.fi/doc/aprs-base91-comment-telemetry.txt.

Returns:

base-91 encoded telemetry String

Throws:

java.lang.IllegalArgumentException - if any value of telemetry message is out of range to fit in base-91 encoding

bodyEquals

public boolean bodyEquals(AX25Message o)

Compare the contents of the body of the message, reporting if they match.

Overrides:

bodyEquals in class Message

Parameters:

o - another AX25Message to compare against

Returns:

boolean true if the body values are equivalent

getBody

public byte[] getBody(boolean countTransmission,
                      ProtocolFamily protocolId,
                      AX25Frame frame)

Get an instance of this message, suitable for transmitting.

Specified by:

getBody in interface SendableMessage

Parameters:

countTransmission - number of times the message has been transmitted.

protocolId - ProtocolFamily to generate the message in; currently, only APRS is supported.

frame - AX25Frame into which the message will be placed; the decoded message (as opposed to the byte array encoding) should be stored into the field frame.parsedAX25Msg

Returns:

byte array of message, or null if message body cannot be generated in specified protocol, or retransmission count has been exceeded.

See Also:

AX25Frame.parsedAX25Msg

isEnabled

public boolean isEnabled()

Test if message should still be transmitted.

Specified by:

isEnabled in interface SendableMessage

Returns:

boolean true if message should still be transmitted

disableForTransmit

public void disableForTransmit()

Specify that message should no longer be transmitted.

Specified by:

disableForTransmit in interface SendableMessage