Advanced
Serial Protocol
Raw Data Update Message
The Raw Data update message communicates the raw gyro, accelerometer, magnetometer and
temperature data. This data bypasses the navX-Sensor Motion Processor, and allows the individual
sensors to be used directly without any intervening processing. This can allow the following types of use:
Access to instantaneous measures of angular velocity in each of the X, Y and Z axes, provided by
the tri-axial gyroscopes. Note that the accelerometer and gyroscope data has already had bias
calibration applied.
Additionally, raw magnetometer data is provided. Note that the raw magnetometer data may have
already had soft/hard iron calibration applied, if the navX-sensor magnetometer calibration
procedure has already been completed.
Byte Offset
Element
Data Type
0
Gyro X (15-bits, signed)
16-bit Integer
4
Gyro Y (15-bits, signed)
16-bit Integer
8
Gyro Z (15-bits, signed)
16-bit Integer
12
Acceleration X (16-bits, signed)
16-bit Integer
16
Acceleration Y (16-bits, signed)
16-bit Integer
20
Acceleration Z (16-bits, signed)
16-bit Integer
24
Magnetometer X (12 bits, signed) 16-bit Integer
28
Magnetometer Y (12 bits, signed) 16-bit Integer
32
Magnetometer Z (12 bits, signed) 16-bit Integer
36
Temperature (Centigrade degrees) Float
Gyro Device Units: value in deg/sec * gyro full scale range
Accelerometer Device Units: value in G * accelerometer full scale range
Magnetometer Device Units: value in uTesla * .15
AHRS / Position Data Update
Byte Offset Element
Data Type
Unit
0
Yaw
Signed Hundredths
Degrees
2
Pitch
Signed Hundredths
Degrees
4
Roll
Signed Hundredths
Degrees
6
Compass Heading Unsigned HundredthsDegrees
8
Altitude
Signed 16:16
Meters
12
Fused Heading
Unsigned HundredthsDegrees
14
Linear Accel X
Signed Thousandths G
16
Linear Accel Y
Signed Thousandths G
18
Linear Accel Z
Signed Thousandths G
20
Velocity X
Signed 16:16
Meters/Sec
83
