PNI CompassPoint V2Xe - Manual (Page 18)

V2Xe User Manual – May 2012 Page 16
kSetCalData (frame ID 0x0E)
This frame writes calibration data into the V2Xe using the same frame structure as
kCalDataResp. This is an optional command and is not used for most applications.
However, it allows the user to store multiple sets of calibration coefficients on the
host system, and write them into the V2Xe when appropriate. For example, if the
host system has a motor that sometimes is off and sometimes on, then one set of
calibration coefficients can be generated and stored in the host system for when the
motor is on, and a second set for when the motor is off. The first set of calibration
coefficients would be written to the V2Xe whenever taking a reading with the motor
on, and the second set whenever the motor is off.
5.6 Making Measurements
To make a measurement, it is first necessary to establish what data is to be output by sending
the kSetDataComponents frame. The kGetData command is sent to initiate a measurement,
and the response will be the kGetDataResp frame which will contain the measured data, as
established by kSetDataComponents.
kSetDataComponents (frame ID 0x03)
This frame defines what data is output when kGetData is sent. Table 5-4 summarizes
the various data components and more detail follows this table. The first byte of the
payload indicates the number of data components followed by the data component
IDs.
Example: To query for heading and magnitude, the payload should contain:
Note that the sequence of the data components defined by kSetDataComponents will
match the output sequence of kGetDataResp.
0x02
Heading ID
0x05
ID Count
Payload
0x06
Magnitude ID
ID Count
UInt8
ID 1
UInt8
Payload
ID 2 ID 3
UInt8 UInt8
……….