HMR3400 Datasheet, PDF (6/9 Pages) Honeywell Accelerometers – Digital Compass Solution

HMR3400
Selects the magnetometer output mode. This configuration is saved in non-volatile memory. All data are in signed
decimal values with user calibration offsets included.
Response Format: MagX, MagY, MagZ<cr><lf>
Eg: 1256, -234, -1894<cr><lf>
Starting and Stopping Data Output
*S<cr><lf>
The data output will toggle between Start and Stop each time this command is issued (factory set default is Start,
first Start/Stop command will stop data output). Continuous data streaming control. Most commands require the
compass to be in a stop condition for the controller to immediately execute the desired command.
Query Output
*Q<cr><lf>
Query for a single output response string in the currently selected mode (Magnetometer/Heading). The *Q
commands are allowed only in Stop data mode. Query commands allow the user to slow the data flow by
requesting each response string.
Roll Axis Re-Zero
*O<cr><lf>
Allows the user to zero the roll output. This command should only be issued when the roll axis is leveled (±0.3°).
Clears Alarm or Warning status after command receipt.
Pitch Axis Re-Zero
*P<cr><lf>
Allows the user to zero the pitch output. This command should only be used when the pitch axis is leveled (±0.3°).
Clears Alarm or Warning status after command receipt.
Averaged Output
*A<cr><lf>
Same result as the query command except that the data are the result of an averaging of 20 readings. The *A
commands are allowed only in Stop data mode. The command response will not occur until the 20 readings
accrue.
Split Filter Toggle
*F<cr><lf>
This command toggles the split filter bit in the configuration status bytes. The parameter setting is saved in the
EEPROM immediately, but not in shadowed in RAM. Requires power cycling or a reset command (*R) to activate.
A set bit indicates the System Filter only smoothes the accelerometer data (Tilt Filter), and the Magnetic Filter is
now active to smooth magnetic sensor data. A cleared filter bit resumes the same smoothing for both the tilt and
magnetometer data.
Reset
*R<cr><lf>
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