Data Sheet

Sensor Documentation Modern Robotics, Inc.
Version 1.4.3 19
Register
Function
0x00
Sensor Firmware Revision
0x01
Manufacturer Code
0x02
Sensor ID Code
0x03
Command
0x04/0x05
Heading Data (lsb/msb)
0x06/0x07
Integrated Z Value (lsb/msb)
0x08/0x09
Raw X Value (lsb/msb)
0x0A/0x0B
Raw Y Value (lsb/msb)
0x0C/0x0D
Raw Z Value (lsb/msb)
0x0E/0x0F
Z Axis Offset (lsb/msb)
0x10/0x11
Z Axis Scaling Coefficient (fsb/lsb)
Command
Operation
EEPROM
Auto-Update
0x00
Normal measurement mode
0x4E
Null gyro offset and reset Z axis integrator
0x52
Reset Z axis integrator
During normal operation the LED will blink briefly at 1Hz. During Null gyro the LED will
be on for the period of calibration.
Gyro Null:
Gyro null is entered by setting the command register to 0x4E. The sensor must be kept
still for 3 seconds while the sensor calibrates. Once the gyro offset has been measured,
the Z axis integrator will be reset to 0 and the command location will reset to 0x00. The
Z axis offset field is used to record the offset value and will be automatically recorded in
EEPROM.
Use 0x52 when resetting your heading value in code. Gyro Null writes to flash memory
with a read/write life cycle.
Gyro Raw Values:
The three fields X, Y and Z are the unprocessed values being obtained from the sensor
element that measure the rate of rotation of an axis. These values are updated at
approximately 760Hz.
Heading Data:
The heading data is obtained by dividing the integrated gyro Z value by 360 yielding a
remainder which is then forced to lie between 0° - 359° as the current heading value. If
rotated in a CW direction, the value increases from 0°. If rotated in a CCW direction, the
value decreases from 359°.