HMC6352 Datasheet, PDF (5/13 Pages) Honeywell Solid State Electronics Center – Digital Compass Solution

HMC6352
Table 1 – HMC6352 Interface Commands/Responses
Command
Byte
ASCII (hex)
w (77)
r (72)
G (47)
g (67)
S (53)
W (57)
O (4F)
C (43)
E (45)
L (4C)
A (41)
Argument 1
Byte
(Binary)
EEPROM
Address
EEPROM
Address
RAM
Address
RAM
Address
Argument 2
Byte
(Binary)
Data
Data
Response 1
Byte
(Binary)
Data
Data
MSB Data
Response 2
Byte
(Binary)
Description
Write to EEPROM
Read from EEPROM
Write to RAM Register
LSB Data
Read from RAM Register
Enter Sleep Mode (Sleep)
Exit Sleep Mode (Wakeup)
Update Bridge Offsets (S/R Now)
Enter User Calibration Mode
Exit User Calibration Mode
Save Op Mode to EEPROM
Get Data. Compensate and
Calculate New Heading
Operational Controls
HMC6352 has two parameters; Operational Mode and Output Mode, which control its operation. The Operational Mode
control byte is located at RAM register byte 74(hex) and is shadowed in EEPROM location 08(hex). This byte can be used
to control the continuous measurement rate, set/reset function, and to command the HMC6352 into the three allowed
operating modes; Standby, Query, and Continuous.
The Output Mode control byte is located at RAM register byte 4E(hex) and is not shadowed in the EEPROM, and upon
power up the device is in the Heading output mode. This byte can be changed to get magnetometer data if necessary but
is typically left in a default heading data mode.
Non-Volatile Memory
The HMC6352 contains non-volatile memory capability in the form of EEPROM that retains key operational parameters
and settings for electronic compassing. Table 2 shows the balance of the EEPROM locations that the user can read and
write to. Details on the features of these location bytes will be discussed in the following paragraphs.
Table 2 – HMC6352 EEPROM Contents
EE Address (hex)
00
01
02
03
04
05
06
07
08
Byte Description
I²C Slave Address
Magnetometer X Offset MSB
Magnetometer X Offset LSB
Magnetometer Y Offset MSB
Magnetometer Y Offset LSB
Time Delay (0 – 255 ms)
Number of Summed measurements(1-16)
Software Version Number
Operation Mode Byte
Factory Default
42(hex)
factory test value
factory test value
factory test value
factory test value
01(hex)
04(hex)
> 01(hex)
50(hex)
Operational Modes
The HMC6352 has three operational modes plus the ability to enter/exit the non-operational (sleep) mode by command.
Sleep mode sends the internal microprocessor into clock shutdown to save power, and can be brought back by the “W”
command (wake). The “S” command returns the processor to sleep mode. The three operational modes are defined by
two bits in the internal HMC6352 Operation Mode register. If the master device sends the “L” command, the current
operational mode control byte in the RAM register is loaded into the internal EEPROM register and becomes the default
operational mode on the next power-up. The application environment of the HMC6352 will dictate the most suitable
operational mode.
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