Protobuf Documentation

The Protobuf messages used by SentiSystems and their definitions can be found here: https://gitlab.senti.no/senti/senti-proto

SentiSystems Message Description

Each Protobuf message output from SentiSystems will be prepended with a synchronization byte, the incoming protobuf message ID, and the length (in bytes) of the Protobuf packet.

That is:

<SYNC_ID><Header.MessageID><message_length><Protobuf message>

The SYNC_ID is set to 0x42.

Header

All packets start with a header

Field	Type	Label	Description
message_id	SentiMessageID
source	uint32		source id of the message (currently used for the port id on SentiBoard)
counter	uint32		Counter of messages of type=message_id sent
tov_ns	uint64		SentiBoard Time-of-Validity converted to nanoseconds
toa_ns	uint64		SentiBoard Time-of-Arrival converted to nanoseconds
utc_s	uint32		UTC timestamp
utc_ns	int32		UTC timestamp ns. Can be negative uBlox style

SentiIMUMsg

Generic IMU Message

Field	Type	Label	Description
header	Header
repeated[3] ang_vel	double		angular velocity in [x,y,z] direction [rad/s]
repeated [3] lin_acc	double		linear acceleration in [x,y,z] direction [m/s²]
is_delta	bool		Are the acceleration/angular velocity values delta values or immediate measurements
temperature	double		temperature in degrees [C]

SentiIMUMagMsg

Generic IMU Message, including magnetometer

Field	Type	Label	Description
header	Header
repeated[3] ang_vel	double		angular velocity in [x,y,z] direction [rad/s]
repeated [3] lin_acc	double		linear acceleration in [x,y,z] direction [m/s²]
is_delta	bool		Are the acceleration/angular velocity values delta values or immediate measurements
temperature	double		temperature in degrees [C]
repeated[3] mag	double		magnetic field in [x,y,z] directions [Gauss]

SentiIMUMagOrientationMsg

Generic IMU Message, including magnetometer and orientation measurements

Field	Type	Label	Description
header	Header
repeated[3] ang_vel	double		angular velocity in [x,y,z] direction [rad/s]
repeated [3] lin_acc	double		linear acceleration in [x,y,z] direction [m/s²]
is_delta	bool		Are the acceleration/angular velocity values delta values or immediate measurements
temperature	double		temperature in degrees [C]
repeated[3] mag	double		magnetic field in [x,y,z] directions [Gauss]
repeated [4] orientation	double		Orientation quaternion [x,y,z,w]
repeated [9] covariance	double		Flattened 3x3 covariance matrix in x,y,z

SentiGNSSPosLLH

Field	Type	Label	Description
header	Header
tow	uint32		time of week
repeated[3] lon_lat_h	double		position in Longitude, Latitude, Height [m]
h_acc	double		horizontal accuracy estimate [m]
v_acc	double		vertical accuracy estimate [m]
repeated [9] covariance	double		flattened 3x3 covariance matrix in x,y,z
fix	SentiFixType		fix type of the receiver

SentiGNSSPosECEF

Field	Type	Label	Description
header	Header
tow	uint32		time of week
repeated[3] xyz	double		position [X,Y,Z] in ECEF frame [m]
acc	double		accuracy estimate [m]
repeated [9] covariance	double		flattened 3x3 covariance matrix in x,y,z
fix	SentiFixType		fix type of the receiver

SentiGNSSVelNED

Field	Type	Label	Description
header	Header
tow	uint32		time of week
repeated[3] vel_ned	double		Velocity in [N,E,D] [m/s]
repeated [9] covariance	double		flattened 3x3 covariance matrix in [N,E,D]
fix	SentiFixType		fix type of the receiver

SentiGNSSVelECEF

Field	Type	Label	Description
header	Header
tow	uint32		time of week
repeated[3] vel_xyz	double		Velocity in [X,Y,Z] (ECEF) [m/s]
repeated [9] covariance	double		flattened 3x3 covariance matrix in [X,Y,Z]
fix	SentiFixType		fix type of the receiver

SentiGNSSRelPos

Generic GNSS Relative Position message containing the relative position between two GNSS receivers

Field	Type	Label	Description
header	Header
tow	uint32		Time of Week
repeated[3] rel_pos_ned	double		relative position in [N,E,D] directions [m]
heading	double		heading/direction between the receivers [rad]
h_acc	double		Horizontal accuracy estimate [m]
v_acc	double		Vertical accuracy estimate [m]
fix	SentiFixType		Fix type of the receiver

SentiGNSSTime

Field	Type	Label	Description
header	Header
tow	uint32		Time of Week
year	uint32
month	uint32
day	uint32
hours	uint32
minutes	uint32
seconds	uint32
nanoseconds	uint32
source	SentiGNSSTimeSource		Type of time source for the time message
t_acc	uint32		Accuracy of reported time

SentiGNSSDop

Generic GNSS Dilution of Precision message. Based on uBlox NAV-DOP message

Field	Type	Label	Description
header	Header
tow	double		Time of Week
p_dop	float		Position DOP
t_dop	float		Time DOP
v_dop	float		Vertical DOP
h_dop	float		Horizontal DOP
n_dop	float		Northing DOP
e_dop	float		Easting DOP

SentiGNSSStatus

Field	Type	Label	Description
header	Header
tow	double		Time of Week
fix_type	SentiFixType		Fix type of the receiver
n_satellites	uint32		Number of tracked satellites

SentiGNSSRfiStatus

Generic RFI status message based on uBloc MON_HW message

Field	Type	Label	Description
header	Header
tow	double		Time of Week
agcCount	uint32
agcCountMax	uint32
jamInd	uint32
jamIndMax	uint32
jammingState	uint32
noiseLevel	uint32

SentiTriggerMsg

SentiBoard Trigger message. UTC timestamp is the rising edge of the trigger

Field	Type	Label	Description
header	Header
rising_edge	uint32		Rising edge TOV value (in SentiBoard time 10*ns)
falling_edge	uint32		falling edge TOV value (in SentiBoard time 10*ns)

SentiInputCaptureMsg

SentiBoard InputCapture message. UTC timestamp is the leading edge of the event

Field	Type	Label	Description
header	Header

SentiRawMsg

Raw SentiBoard packet. A sensor data packet (raw byte stream) wrapped in the Header with UTC timestamp

Field	Type	Label	Description
header	Header
packet	bytes		Raw sensor data packet

SentiINSAllStates

Field	Type	Label	Description
header	Header
llh	double	repeated	Longitude, Latitude, Height [rad, rad, m]
height_msl	double		Height over mean sea level [m]
height_geoid	double		Height over geoid [m]
pos_lb_l_xyz	double	repeated	Local frame estimated position [m, m, m]
vel_eb_n_xyz	double	repeated	Estimated NED velocities [m/s]
roll	double		Roll [rad]
pitch	double		Pitch [rad]
yaw	double		Yaw [rad]
quaternion	double	repeated	Attitude quaternion [x, y, z, w]
pos_eb_e_xyz	double	repeated	Estimated ECEF position [m]
vel_eb_e_xyz	double	repeated	Estimated ECEF velocities [m/s]
cog	double		Course over ground [rad]
sog	double		Speed over ground [m/s]
fix_status	uint32		Fix status
heave	double		Heave [m]
ang_vel_nb_b_xyz	double	repeated	Angular velocity of body frame [rad/s]
lin_acc_eb_b_xyz	double	repeated	Linear acceleration of body frame [m/s²]
cov_pos_eb_n_xyz	double	repeated	Covariance of NED position [m²]
cov_vel_eb_n_xyz	double	repeated	Covariance of NED velocity [m²/s²]
cov_accel_eb_n_xyz	double	repeated	Covariance of NED acceleration [m²/s⁴]

SentiINSStates

Field	Type	Label	Description
header	Header
llh	double	repeated	Longitude, Latitude, Height [rad, rad, m]
height_msl	double		Height over mean sea level [m]
height_geoid	double		Height over geoid [m]
pos_lb_l_xyz	double	repeated	Local frame estimated position [m, m, m]
vel_eb_n_xyz	double	repeated	Estimated NED velocities [m/s]
roll	double		Roll [rad]
pitch	double		Pitch [rad]
yaw	double		Yaw [rad]
quaternion	double	repeated	Attitude quaternion [x, y, z, w]
pos_eb_e_xyz	double	repeated	Estimated ECEF position [m]
vel_eb_e_xyz	double	repeated	Estimated ECEF velocities [m/s]
cog	double		Course over ground [rad]
sog	double		Speed over ground [m/s]
fix_status	uint32		Fix status
heave	double		Heave [m]
ang_vel_nb_b_xyz	double	repeated	Angular velocity of body frame [rad/s]
lin_acc_eb_b_xyz	double	repeated	Linear acceleration of body frame [m/s²]

SentiINSPosStates

Field	Type	Label	Description
header	Header
llh	double	repeated	Longitude, Latitude, Height [rad, rad, m]
height_msl	double		Height over mean sea level [m]
height_geoid	double		Height over geoid [m]
pos_lb_l_xyz	double	repeated	Local frame estimated position [m, m, m]
pos_eb_e_xyz	double	repeated	Estimated ECEF coordinates [m]
heave	double		Heave [m]
fix_status	uint32		Fix status

SentiINSVelStates

Field	Type	Label	Description
header	Header
vel_eb_n_xyz	double	repeated	Estimated NED velocities [m/s]
vel_eb_e_xyz	double	repeated	Estimated ECEF velocities [m/s]
cog	double		Course over ground [rad]
sog	double		Speed over ground [m/s]

SentiINSAttStates

Field	Type	Label	Description
header	Header
roll	double		Roll [rad]
pitch	double		Pitch [rad]
yaw	double		Yaw [rad]
quaternion	double	repeated	Attitude quaternion [x, y, z, w]

SentiINSRotVelStates

Field	Type	Label	Description
header	Header
ang_vel_nb_b_xyz	double	repeated	Angular velocity of body frame [rad/s]

SentiINSAccStates

Field	Type	Label	Description
header	Header
lin_acc_eb_b_xyz	double	repeated	Linear acceleration of body frame [m/s²]

SentiINSCovariance

Field	Type	Label	Description
header	Header
cov_pos_eb_n_xyz	double	repeated	Covariance of NED position [m²]
cov_vel_eb_n_xyz	double	repeated	Covariance of NED velocity [m²/s²]
cov_accel_eb_n_xyz	double	repeated	Covariance of NED acceleration [m²/s⁴]

SentiIMUBiasStates

Field	Type	Label	Description
header	Header
b_ars_b_xyz	double	repeated	Gyroscope (angular rate) bias [rad/s]
b_acc_b_xyz	double	repeated	Accelerometer bias [m/s²]

SentiRFIStates

Field	Type	Label	Description
header	Header
agc_count_level	float		AGC count. See GNSSRfiStatus
jam_ind_level	float		Jamming indicator. See GNSSRfiStatus
jam_state	uint32		Jamming state. See GNSSRfiStatus

Enums

SentiMessageID

MessageID uniquely identifies all messages sent in SentiUtils

Name	Number
NONE	0
RAW_MSG	1
BUFFER_MSG	2
BASE_MSG	3
IMU_MSG	100
IMU_MAG_MSG	101
IMU_MAG_ORIENTATION_MSG	102
IMAGE_MSG	150
GNSS_POS_LLH	200
GNSS_POS_ECEF	201
GNSS_VEL_NED	202
GNSS_VEL_ECEF	203
GNSS_RELPOS_NED	204
GNSS_TIME	205
GNSS_DOP	206
GNSS_STATUS	207
GNSS_RFI_STATUS	208
TRIGGER_MSG	300
INPUTCAPTURE_MSG	400
NMEA_GGA	500
NMEA_ZDA	501
_UNUSED	65534

SentiGNSSTimeSource

Name	Number	Description
NO_SOURCE	0
PROPAGATED	1
GNSS	2

SentiFixType

Name	Number	Description
NO_FIX	0
GNSS_FIX	1
DGNSS_FIX	2
RTK_FIX	3
RTK_FLOAT	4
DEAD_RECKOGNING	5
SBAS_FIX	6

Scalar Value Types

See Protobuf documentation for scalar value types.