[HS-56] Add time offset message

c/include/libsbp/cpp/message_traits.h

@@ -1091,6 +1091,12 @@ struct MessageTraits<msg_ins_updates_t> {
 };
 
 
+template<>
+struct MessageTraits<msg_gnss_time_offset_t> {
+  static constexpr u16 id = 65287;
+};
+
+
 template<>
 struct MessageTraits<msg_heartbeat_t> {
   static constexpr u16 id = 65535;

c/include/libsbp/imu.h

@@ -34,6 +34,11 @@ SBP_PACK_START
  * gyroscope readings. The sense of the measurements are to be aligned with 
  * the indications on the device itself. Measurement units, which are specific to the
  * device hardware and settings, are communicated via the MSG_IMU_AUX message.
+ * If using "time since startup" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise IMU measurements
+ * with GNSS.
+ * 
+ * The time-tagging mode should not change throughout a run.
  */
 #define SBP_MSG_IMU_RAW 0x0900
 typedef struct SBP_ATTR_PACKED {

c/include/libsbp/system.h

@@ -131,6 +131,21 @@ typedef struct SBP_ATTR_PACKED {
 } msg_ins_updates_t;
 
 
+/** Offset of the local time with respect to GNSS time
+ *
+ * The GNSS time offset message contains the information that is needed to translate messages
+ * tagged with a local timestamp (e.g. IMU or wheeltick messages) to GNSS time for the sender
+ * producing this message.
+ */
+#define SBP_MSG_GNSS_TIME_OFFSET      0xFF07
+typedef struct SBP_ATTR_PACKED {
+  s16 weeks;           /**< Weeks portion of the time offset [weeks] */
+  s32 milliseconds;    /**< Milliseconds portion of the time offset [ms] */
+  s16 microseconds;    /**< Microseconds portion of the time offset [microseconds] */
+  u8 flags;           /**< Status flags (reserved) */
+} msg_gnss_time_offset_t;
+
+
 /** \} */
 
 SBP_PACK_END

c/include/libsbp/vehicle.h

@@ -35,6 +35,9 @@ SBP_PACK_START
  * the definition and origin of the user frame are defined through the device settings interface.
  * There are 4 possible user-defined sources of this message  which are labeled arbitrarily 
  * source 0 through 3.
+ * If using "processor time" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise odometry measurements
+ * with GNSS.
  */
 #define SBP_MSG_ODOMETRY  0x0903
 typedef struct SBP_ATTR_PACKED {
@@ -57,6 +60,9 @@ for the exact source of this timestamp.
  * from 0 to 255.
  * The timestamp associated with this message should represent the time when the accumulated
  * tick count reached the value given by the contents of this message as accurately as possible.
+ * If using "local CPU time" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise wheeltick measurements
+ * with GNSS.
  */
 #define SBP_MSG_WHEELTICK 0x0904
 typedef struct SBP_ATTR_PACKED {

haskell/src/SwiftNav/SBP/Imu.hs

@@ -44,7 +44,10 @@ msgImuRaw = 0x0900
 -- gyroscope readings. The sense of the measurements are to be aligned with
 -- the indications on the device itself. Measurement units, which are specific
 -- to the device hardware and settings, are communicated via the MSG_IMU_AUX
--- message.
+-- message. If using "time since startup" time tags, the receiving end will
+-- expect a `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to
+-- synchronise IMU measurements with GNSS.  The time-tagging mode should not
+-- change throughout a run.
 data MsgImuRaw = MsgImuRaw
   { _msgImuRaw_tow :: !Word32
     -- ^ Milliseconds since reference epoch and time status.

haskell/src/SwiftNav/SBP/Msg.hs

@@ -129,6 +129,7 @@ data SBPMsg =
    | SBPMsgFwd MsgFwd Msg
    | SBPMsgGloBiases MsgGloBiases Msg
    | SBPMsgGnssCapb MsgGnssCapb Msg
+   | SBPMsgGnssTimeOffset MsgGnssTimeOffset Msg
    | SBPMsgGpsTime MsgGpsTime Msg
    | SBPMsgGpsTimeDepA MsgGpsTimeDepA Msg
    | SBPMsgGroupDelay MsgGroupDelay Msg
@@ -327,6 +328,7 @@ instance Binary SBPMsg where
           | _msgSBPType == msgFwd = SBPMsgFwd (decode (fromStrict (unBytes _msgSBPPayload))) m
           | _msgSBPType == msgGloBiases = SBPMsgGloBiases (decode (fromStrict (unBytes _msgSBPPayload))) m
           | _msgSBPType == msgGnssCapb = SBPMsgGnssCapb (decode (fromStrict (unBytes _msgSBPPayload))) m
+          | _msgSBPType == msgGnssTimeOffset = SBPMsgGnssTimeOffset (decode (fromStrict (unBytes _msgSBPPayload))) m
           | _msgSBPType == msgGpsTime = SBPMsgGpsTime (decode (fromStrict (unBytes _msgSBPPayload))) m
           | _msgSBPType == msgGpsTimeDepA = SBPMsgGpsTimeDepA (decode (fromStrict (unBytes _msgSBPPayload))) m
           | _msgSBPType == msgGroupDelay = SBPMsgGroupDelay (decode (fromStrict (unBytes _msgSBPPayload))) m
@@ -517,6 +519,7 @@ instance Binary SBPMsg where
       encoder (SBPMsgFwd _ m) = put m
       encoder (SBPMsgGloBiases _ m) = put m
       encoder (SBPMsgGnssCapb _ m) = put m
+      encoder (SBPMsgGnssTimeOffset _ m) = put m
       encoder (SBPMsgGpsTime _ m) = put m
       encoder (SBPMsgGpsTimeDepA _ m) = put m
       encoder (SBPMsgGroupDelay _ m) = put m
@@ -711,6 +714,7 @@ instance FromJSON SBPMsg where
         | msgType == msgFwd = SBPMsgFwd <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
         | msgType == msgGloBiases = SBPMsgGloBiases <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
         | msgType == msgGnssCapb = SBPMsgGnssCapb <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
+        | msgType == msgGnssTimeOffset = SBPMsgGnssTimeOffset <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
         | msgType == msgGpsTime = SBPMsgGpsTime <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
         | msgType == msgGpsTimeDepA = SBPMsgGpsTimeDepA <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
         | msgType == msgGroupDelay = SBPMsgGroupDelay <$> pure (decode (fromStrict (unBytes payload))) <*> parseJSON obj
@@ -906,6 +910,7 @@ instance ToJSON SBPMsg where
   toJSON (SBPMsgFwd n m) = toJSON n <<>> toJSON m
   toJSON (SBPMsgGloBiases n m) = toJSON n <<>> toJSON m
   toJSON (SBPMsgGnssCapb n m) = toJSON n <<>> toJSON m
+  toJSON (SBPMsgGnssTimeOffset n m) = toJSON n <<>> toJSON m
   toJSON (SBPMsgGpsTime n m) = toJSON n <<>> toJSON m
   toJSON (SBPMsgGpsTimeDepA n m) = toJSON n <<>> toJSON m
   toJSON (SBPMsgGroupDelay n m) = toJSON n <<>> toJSON m
@@ -1095,6 +1100,7 @@ instance HasMsg SBPMsg where
   msg f (SBPMsgFwd n m) = SBPMsgFwd n <$> f m
   msg f (SBPMsgGloBiases n m) = SBPMsgGloBiases n <$> f m
   msg f (SBPMsgGnssCapb n m) = SBPMsgGnssCapb n <$> f m
+  msg f (SBPMsgGnssTimeOffset n m) = SBPMsgGnssTimeOffset n <$> f m
   msg f (SBPMsgGpsTime n m) = SBPMsgGpsTime n <$> f m
   msg f (SBPMsgGpsTimeDepA n m) = SBPMsgGpsTimeDepA n <$> f m
   msg f (SBPMsgGroupDelay n m) = SBPMsgGroupDelay n <$> f m

haskell/src/SwiftNav/SBP/System.hs

@@ -266,3 +266,40 @@ instance Binary MsgInsUpdates where
 $(makeSBP 'msgInsUpdates ''MsgInsUpdates)
 $(makeJSON "_msgInsUpdates_" ''MsgInsUpdates)
 $(makeLenses ''MsgInsUpdates)
+
+msgGnssTimeOffset :: Word16
+msgGnssTimeOffset = 0xFF07
+
+-- | SBP class for message MSG_GNSS_TIME_OFFSET (0xFF07).
+--
+-- The GNSS time offset message contains the information that is needed to
+-- translate messages tagged with a local timestamp (e.g. IMU or wheeltick
+-- messages) to GNSS time for the sender producing this message.
+data MsgGnssTimeOffset = MsgGnssTimeOffset
+  { _msgGnssTimeOffset_weeks      :: !Int16
+    -- ^ Weeks portion of the time offset
+  , _msgGnssTimeOffset_milliseconds :: !Int32
+    -- ^ Milliseconds portion of the time offset
+  , _msgGnssTimeOffset_microseconds :: !Int16
+    -- ^ Microseconds portion of the time offset
+  , _msgGnssTimeOffset_flags      :: !Word8
+    -- ^ Status flags (reserved)
+  } deriving ( Show, Read, Eq )
+
+instance Binary MsgGnssTimeOffset where
+  get = do
+    _msgGnssTimeOffset_weeks <- (fromIntegral <$> getWord16le)
+    _msgGnssTimeOffset_milliseconds <- (fromIntegral <$> getWord32le)
+    _msgGnssTimeOffset_microseconds <- (fromIntegral <$> getWord16le)
+    _msgGnssTimeOffset_flags <- getWord8
+    pure MsgGnssTimeOffset {..}
+
+  put MsgGnssTimeOffset {..} = do
+    (putWord16le . fromIntegral) _msgGnssTimeOffset_weeks
+    (putWord32le . fromIntegral) _msgGnssTimeOffset_milliseconds
+    (putWord16le . fromIntegral) _msgGnssTimeOffset_microseconds
+    putWord8 _msgGnssTimeOffset_flags
+
+$(makeSBP 'msgGnssTimeOffset ''MsgGnssTimeOffset)
+$(makeJSON "_msgGnssTimeOffset_" ''MsgGnssTimeOffset)
+$(makeLenses ''MsgGnssTimeOffset)

haskell/src/SwiftNav/SBP/Vehicle.hs

@@ -44,7 +44,9 @@ msgOdometry = 0x0903
 -- odometry reference point and  the definition and origin of the user frame
 -- are defined through the device settings interface. There are 4 possible
 -- user-defined sources of this message  which are labeled arbitrarily  source
--- 0 through 3.
+-- 0 through 3. If using "processor time" time tags, the receiving end will
+-- expect a `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to
+-- synchronise odometry measurements with GNSS.
 data MsgOdometry = MsgOdometry
   { _msgOdometry_tow    :: !Word32
     -- ^ Time field representing either milliseconds in the GPS Week or local CPU
@@ -84,7 +86,9 @@ msgWheeltick = 0x0904
 -- identified by the source field, which is an integer ranging from 0 to 255.
 -- The timestamp associated with this message should represent the time when
 -- the accumulated tick count reached the value given by the contents of this
--- message as accurately as possible.
+-- message as accurately as possible. If using "local CPU time" time tags, the
+-- receiving end will expect a `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes
+-- available to synchronise wheeltick measurements with GNSS.
 data MsgWheeltick = MsgWheeltick
   { _msgWheeltick_time :: !Word64
     -- ^ Time field representing either microseconds since the last PPS,

java/src/com/swiftnav/sbp/client/MessageTable.java

@@ -188,6 +188,7 @@
 import com.swiftnav.sbp.system.MsgCsacTelemetry;
 import com.swiftnav.sbp.system.MsgCsacTelemetryLabels;
 import com.swiftnav.sbp.system.MsgInsUpdates;
+import com.swiftnav.sbp.system.MsgGnssTimeOffset;
 import com.swiftnav.sbp.tracking.MsgTrackingStateDetailedDepA;
 import com.swiftnav.sbp.tracking.MsgTrackingStateDetailedDep;
 import com.swiftnav.sbp.tracking.MsgTrackingState;
@@ -550,6 +551,8 @@ static SBPMessage dispatch(SBPMessage msg) throws SBPBinaryException {
                 return new MsgCsacTelemetryLabels(msg);
             case MsgInsUpdates.TYPE:
                 return new MsgInsUpdates(msg);
+            case MsgGnssTimeOffset.TYPE:
+                return new MsgGnssTimeOffset(msg);
             case MsgTrackingStateDetailedDepA.TYPE:
                 return new MsgTrackingStateDetailedDepA(msg);
             case MsgTrackingStateDetailedDep.TYPE:

java/src/com/swiftnav/sbp/imu/MsgImuRaw.java

@@ -31,7 +31,12 @@
  * Raw data from the Inertial Measurement Unit, containing accelerometer and
  * gyroscope readings. The sense of the measurements are to be aligned with 
  * the indications on the device itself. Measurement units, which are specific to the
- * device hardware and settings, are communicated via the MSG_IMU_AUX message. */
+ * device hardware and settings, are communicated via the MSG_IMU_AUX message.
+ * If using "time since startup" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise IMU measurements
+ * with GNSS.
+ * 
+ * The time-tagging mode should not change throughout a run. */
 
 public class MsgImuRaw extends SBPMessage {
     public static final int TYPE = 0x0900;

java/src/com/swiftnav/sbp/system/MsgGnssTimeOffset.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2015-2018 Swift Navigation Inc.
+ * Contact: Swift Navigation <dev@swiftnav.com>
+ *
+ * This source is subject to the license found in the file 'LICENSE' which must
+ * be be distributed together with this source. All other rights reserved.
+ *
+ * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
+ * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
+ */
+
+package com.swiftnav.sbp.system;
+
+import java.math.BigInteger;
+
+import com.swiftnav.sbp.SBPMessage;
+import com.swiftnav.sbp.SBPBinaryException;
+import com.swiftnav.sbp.SBPStruct;
+
+import org.json.JSONObject;
+import org.json.JSONArray;
+
+
+/** SBP class for message MSG_GNSS_TIME_OFFSET (0xFF07).
+ *
+ * You can have MSG_GNSS_TIME_OFFSET inherent its fields directly from
+ * an inherited SBP object, or construct it inline using a dict of its
+ * fields.
+ *
+ * The GNSS time offset message contains the information that is needed to translate messages
+ * tagged with a local timestamp (e.g. IMU or wheeltick messages) to GNSS time for the sender
+ * producing this message. */
+
+public class MsgGnssTimeOffset extends SBPMessage {
+    public static final int TYPE = 0xFF07;
+
+
+    /** Weeks portion of the time offset */
+    public int weeks;
+
+    /** Milliseconds portion of the time offset */
+    public int milliseconds;
+
+    /** Microseconds portion of the time offset */
+    public int microseconds;
+
+    /** Status flags (reserved) */
+    public int flags;
+
+
+    public MsgGnssTimeOffset (int sender) { super(sender, TYPE); }
+    public MsgGnssTimeOffset () { super(TYPE); }
+    public MsgGnssTimeOffset (SBPMessage msg) throws SBPBinaryException {
+        super(msg);
+        assert msg.type != TYPE;
+    }
+
+    @Override
+    protected void parse(Parser parser) throws SBPBinaryException {
+        /* Parse fields from binary */
+        weeks = parser.getS16();
+        milliseconds = parser.getS32();
+        microseconds = parser.getS16();
+        flags = parser.getU8();
+    }
+
+    @Override
+    protected void build(Builder builder) {
+        builder.putS16(weeks);
+        builder.putS32(milliseconds);
+        builder.putS16(microseconds);
+        builder.putU8(flags);
+    }
+
+    @Override
+    public JSONObject toJSON() {
+        JSONObject obj = super.toJSON();
+        obj.put("weeks", weeks);
+        obj.put("milliseconds", milliseconds);
+        obj.put("microseconds", microseconds);
+        obj.put("flags", flags);
+        return obj;
+    }
+}

java/src/com/swiftnav/sbp/vehicle/MsgOdometry.java

@@ -32,7 +32,10 @@
  * reference point(s) specified by the user. The offset for the odometry reference point and 
  * the definition and origin of the user frame are defined through the device settings interface.
  * There are 4 possible user-defined sources of this message  which are labeled arbitrarily 
- * source 0 through 3. */
+ * source 0 through 3.
+ * If using "processor time" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise odometry measurements
+ * with GNSS. */
 
 public class MsgOdometry extends SBPMessage {
     public static final int TYPE = 0x0903;

java/src/com/swiftnav/sbp/vehicle/MsgWheeltick.java

@@ -34,7 +34,10 @@
  * The source of this message is identified by the source field, which is an integer ranging
  * from 0 to 255.
  * The timestamp associated with this message should represent the time when the accumulated
- * tick count reached the value given by the contents of this message as accurately as possible. */
+ * tick count reached the value given by the contents of this message as accurately as possible.
+ * If using "local CPU time" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise wheeltick measurements
+ * with GNSS. */
 
 public class MsgWheeltick extends SBPMessage {
     public static final int TYPE = 0x0904;

javascript/sbp/imu.js

@@ -29,7 +29,11 @@ var UInt64 = require('cuint').UINT64;
  * Raw data from the Inertial Measurement Unit, containing accelerometer and
  * gyroscope readings. The sense of the measurements are to be aligned with  the
  * indications on the device itself. Measurement units, which are specific to the
- * device hardware and settings, are communicated via the MSG_IMU_AUX message.
+ * device hardware and settings, are communicated via the MSG_IMU_AUX message. If
+ * using "time since startup" time tags, the receiving end will expect a
+ * `MSG_GNSS_TIME_OFFSET` when a PVT fix becomes available to synchronise IMU
+ * measurements with GNSS.  The time-tagging mode should not change throughout a
+ * run.
  *
  * Fields in the SBP payload (`sbp.payload`):
  * @field tow number (unsigned 32-bit int, 4 bytes) Milliseconds since reference epoch and time status.

javascript/sbp/system.js

@@ -267,6 +267,44 @@ MsgInsUpdates.prototype.fieldSpec.push(['speed', 'writeUInt8', 1]);
 MsgInsUpdates.prototype.fieldSpec.push(['nhc', 'writeUInt8', 1]);
 MsgInsUpdates.prototype.fieldSpec.push(['zerovel', 'writeUInt8', 1]);
 
+/**
+ * SBP class for message MSG_GNSS_TIME_OFFSET (0xFF07).
+ *
+ * The GNSS time offset message contains the information that is needed to
+ * translate messages tagged with a local timestamp (e.g. IMU or wheeltick
+ * messages) to GNSS time for the sender producing this message.
+ *
+ * Fields in the SBP payload (`sbp.payload`):
+ * @field weeks number (signed 16-bit int, 2 bytes) Weeks portion of the time offset
+ * @field milliseconds number (signed 32-bit int, 4 bytes) Milliseconds portion of the time offset
+ * @field microseconds number (signed 16-bit int, 2 bytes) Microseconds portion of the time offset
+ * @field flags number (unsigned 8-bit int, 1 byte) Status flags (reserved)
+ *
+ * @param sbp An SBP object with a payload to be decoded.
+ */
+var MsgGnssTimeOffset = function (sbp, fields) {
+  SBP.call(this, sbp);
+  this.messageType = "MSG_GNSS_TIME_OFFSET";
+  this.fields = (fields || this.parser.parse(sbp.payload));
+
+  return this;
+};
+MsgGnssTimeOffset.prototype = Object.create(SBP.prototype);
+MsgGnssTimeOffset.prototype.messageType = "MSG_GNSS_TIME_OFFSET";
+MsgGnssTimeOffset.prototype.msg_type = 0xFF07;
+MsgGnssTimeOffset.prototype.constructor = MsgGnssTimeOffset;
+MsgGnssTimeOffset.prototype.parser = new Parser()
+  .endianess('little')
+  .int16('weeks')
+  .int32('milliseconds')
+  .int16('microseconds')
+  .uint8('flags');
+MsgGnssTimeOffset.prototype.fieldSpec = [];
+MsgGnssTimeOffset.prototype.fieldSpec.push(['weeks', 'writeInt16LE', 2]);
+MsgGnssTimeOffset.prototype.fieldSpec.push(['milliseconds', 'writeInt32LE', 4]);
+MsgGnssTimeOffset.prototype.fieldSpec.push(['microseconds', 'writeInt16LE', 2]);
+MsgGnssTimeOffset.prototype.fieldSpec.push(['flags', 'writeUInt8', 1]);
+
 module.exports = {
   0xFF00: MsgStartup,
   MsgStartup: MsgStartup,
@@ -282,4 +320,6 @@ module.exports = {
   MsgCsacTelemetryLabels: MsgCsacTelemetryLabels,
   0xFF06: MsgInsUpdates,
   MsgInsUpdates: MsgInsUpdates,
+  0xFF07: MsgGnssTimeOffset,
+  MsgGnssTimeOffset: MsgGnssTimeOffset,
 }