HMC6343 Datasheet, PDF (12/13 Pages) Honeywell Solid State Electronics Center – 3-Axis Digital Compass Module

HMC6343
Operational Mode Registers
EEPROM registers 0x04 and 0x05 contain Bytes that are read for operational mode status and for setting the Run Mode
measurement rate. The tables below describe the register contents and interpretation. It is recommended that Operational
Mode Register 1 be read only, and register 2 written only to change update rate.
Table 4 – Operational Mode Register 1 (EEPROM 0x04)
OM1_7 OM1_6 OM1_5 OM1_4 OM1_3 OM1_2 OM1_1 OM1_0
Comp(0) Cal(0) Filter(0) Run(1) Stdby(0) UF(0) UE(0) Level(1)
Table 5 – Operational Mode Register 1 Bit Designations
Location Name
Description
OM1_7
Comp
Calculating compass data if set. (read only)
OM1_6
OM1_5
OM1_4
OM1_3
OM1_2
Cal
Filter
Run
Stdby
UF
Calculating calibration offsets if set. (read only)
IIR Heading Filter used if set.
Run Mode if set.
Standby Mode if set.
Upright Front Orientation if set.
OM1_1
UE
Upright Edge Orientation if set.
OM1_0
Level
Level Orientation if set
Table 6 – Operational Mode Register 2 (EEPROM 0x05)
OM2_7 OM2_6 OM2_5 OM2_4 OM2_3 OM2_2 OM2_1 OM2_0
(0)
(0)
(0)
(0)
(0)
(0)
MR1(0) MR0(1)
Table 7 – Operational Mode Register 2 Bit Designations
Location Name
Description
OM1_7 to
OM2_2
0
These bits must be cleared for correct operation.
OM2_1 to
OM2_0
MR1, MR0
Measurement Rate
0,0 = 1Hz
0,1 = 5Hz (default)
1,0 = 10Hz
1,1 = Not Assigned
User Hard-Iron Calibration
The HMC6343 provides a user calibration routine with the 0x70 command permitting entry into the calibration mode and
the 0x7F command to exit the calibration mode. During the calibration procedure, the compass and the platform to which
the compass is attached is rotated at a reasonably steady speed through 360 degrees. This process should at least take
one minute for best accuracy. For best HM C6343 calibration, the rotation should include as much pitch and roll
orientations possible. The calibration time window is recommended to be from 60 seconds up to 3 minutes depending on
the end user’s platform.
The calibration routine collects these readings to correct for hard-iron distortions of the magnetic field. These hard-iron
effects are due to magnetized materials nearby the HMC6343 part that in a fixed position with respect to the end user
platform. An example would be the magnetized chassis or engine block of a vehicle in which the compass is mounted
onto. Upon exiting the calibration mode, the resulting magnetometer offsets and scaling factors are updated.
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