User Manual
© 2017 Inertial Sense, LLC
14
11/30/2017
The packet checksum is an 8 bit integer and is calculated by calculating the exclusive OR of all bytes in between
and not including the $ and * bytes. The packet checksum byte is converted to a 2 byte ASCII hex code, and left
padded with 0 if necessary to ensure that it is always 2 bytes. The checksum is always lowercase hexadecimal
characters. See
https://en.wikipedia.org/wiki/NMEA_0183#Message_structure
for more details.
The hardware has the following built in messages that can be broadcast. These can be enabled by sending the
following ASCII packet:
5.2.1
ASCII Messages
The following ASCII messages are supported. Field codes are: lf = double, f = float, d = int.
ASCB
–
Enable ASCII message and set broadcast periods. The period is in milliseconds with no thousands
separator character
. “xx” is the two
-character checksum. Each field can be left blank in which case the
existing broadcast period for that field is not modified, or 0 to disable.
$ASCB,d,d,d,d,d,d,d,d,d*xx\r\n
Field
Units Description
IMU
ms
Broadcast period for PIMU message
DTV
ms
Broadcast period for PDTV message
INS1
ms
Broadcast period for PINS1 message
INS2
ms
Broadcast period for PINS2 message
GPSP
ms
Broadcast period for PGPSPOS message
GPSV
ms
Broadcast period for PGPSVEL message
GGA
ms
Broadcast period for NMEA GPGGA message
GLL
ms
Broadcast period for NMEA GPGLL message
GSA
ms
Broadcast period for NMEA GPGSA message
STPB
–
Stopping all broadcasts (both binary and ASCII) can be accomplished by sending the following packet:
$STPB*15\r\n
PIMU
–
Dual IMU sensor data (two sets of 3-axis gyros and accelerometers) in the body frame.
$PIMU,lf,d,f,f,f,f,f,f,f,f,f,f,f,f *xx\r\n
Field
Units
Description
timeSinceBoot
sec
Time since system power up
IMU1 pqr[0]
rad/sec
IMU1 angular rate gyro
–
pitch
IMU1 pqr[1]
rad/sec
IMU1 angular rate gyro
–
roll
IMU1 pqr[2]
rad/sec
IMU1 angular rate gyro
–
yaw
IMU1 acc[0]
m/s
2
IMU1 linear acceleration
–
X
IMU1 acc[1]
m/s
2
IMU1 linear acceleration
–
Y
IMU1 acc[2]
m/s
2
IMU1 linear acceleration
–
Z
IMU2 pqr[0]
rad/sec
IMU2 angular rate gyro
–
pitch
IMU2 pqr[1]
rad/sec
IMU2 angular rate gyro
–
roll
IMU2 pqr[2]
rad/sec
IMU2 angular rate gyro
–
yaw
IMU2 acc[0]
m/s
2
IMU2 linear acceleration
–
X
IMU2 acc[1]
m/s
2
IMU2 linear acceleration
–
Y
IMU2 acc[2]
m/s
2
IMU2 linear acceleration
–
Z
PDTV
–
Delta theta velocity (conning and sculling integrals) in the body frame.
