3DM-GX5-45
™
GNSS-Aided Inertial Navigation System
DCP Manual
4.2.19
Magnetometer Hard Iron Offset (0x0C, 0x3A)
Description
This command will read or write values to the magnetometer Hard Iron Offset Vector.
For all functions except 0x01 and 0x06 (apply new settings), the new vector value is
ignored. The offset value is subtracted from the scaled Mag value prior to output.
The values for this offset are determined empirically by external software algorithms
based on calibration data taken after the device is installed in its application. These values
can be obtained and set by using the LORD “MIP Iron Calibration” application.
Alternatively, the
feature may be used to capture these values in-run.
The offset is applied to the scaled magnetometer vector prior to output.
Possible function selector values:
0x01 - Apply new settings
0x02 – Read back current settings
0x03 – Save current settings as startup settings
0x04 – Load saved startup settings
0x05 – Load factory default settings
0x06 - Apply new settings with no ACK/NACK reply
Default values:
Hard Iron Offset: [0,0,0]
Field Format
Field Length
Field
Descriptor
Field Data
Command
0x0F
0x3A
U8 – Function selector
float - X Hard Iron Offset
float - Y Hard Iron Offset
float - Z Hard Iron Offset
Reply Field 1:
ACK/ NACK
0x04
0xF1
U8 - echo the command byte
U8 - error code (0: ACK, non-zero: NACK)
Reply Field 2:
Function = 2
0x0E
0x9C
float - Current X Hard Iron Offset
float - Current Y Hard Iron Offset
float - Current Z Hard Iron Offset
Examples
MIP Packet Header
Command/Reply Fields
Checksum
Sync1
Sync2
Desc.
Set
Payload
Length
Field
Length
Field
Desc.
Field Data
MSB
LSB
Command:
Hard Iron Offset
0x75
0x65
0x0C
0x0F
0x0F
0x3A
Fctn (Apply): 0x01
Offset Vector: 0x00000000
0x00000000
0x00000000
0x3F
0x9F
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