PNI CompassPoint V2Xe Скачать руководство пользователя страница 19

 

PNI Sensor Corporation 

DOC#1017814 r01 

V2Xe User Manual 

– May 2012 

Page 17 

Table 5-4:  Component Identifiers 

Component 

Component ID 

Format 

Units 

kXRaw 

0x01 

SInt32 

counts 

kYRaw 

0x02 

Sint32 

counts 

kXCal 

0x03 

Float32 

scaled to 1.0 

kYCal 

0x04 

Float32 

scaled to 1.0 

kHeading 

0x05 

Float32 

degrees 

kMagnitude 

0x06 

Float32 

scaled to 1.0 

kTemperature 

0x07 

Float32 

°C 

kDistortion 

0x08 

Boolean 

True or False 

kCalStatus 

0x09 

Boolean 

True or False 

 

Component types are listed below.  All are read-only values. 

kXRaw & kYRaw (Component IDs 1

d

 & 2

d

These values are the raw sensor counts as read from the ASIC registers. 

kXCal & kYCal (Component IDs 3

d

 & 4

d

These  are  the  X  and  Y  components  of  the  magnetic  vector  after  the  calibration 

coefficients  have  been  applied  to  the  raw  values.    Their  values  are  used  to 

calculate the heading. 

kHeading

 

(Component ID 5

d

Provides compass heading calculated from kXCal and kYCal, where the heading 

range is 0.0˚ to +359.9.  kHeading will equal -1.00 if kCalStatus is True. 

kMagnitude

 

(Component ID 0x06) 

The value is calculated using the formula Magnitude = SQRT (XCal2 + YCal2).  

Its value is compared to the calibration magnitude to determine distortion. 

kTemperature (Component ID 0x07) 

The V2Xe’s internal temperature sensor provides the temperature value, in 

°

C. 

kDistortion (Component ID 0x08)

 

This flag indicates if the magnitude of the vector used to calculate the heading is 

below 50% or above 150% of the calibration magnitude. 

kCalStatus (Component ID 0x09)

 

This flag indicates the user calibration status.  True means it is not user calibrated 

and this is the default value. 

kGetData (frame ID 0x04) 

This  frame queries the  V2Xe for data.   The frame has no payload.   The response is 

kGetDataResp. 

Содержание CompassPoint V2Xe

Страница 1: ...User Manual CompassPoint V2Xe Electronic 2 Axis Compass Module...

Страница 2: ...ting 6 4 3 SPI Hardware Protocol 6 5 OPERATION WITH V2XE PROTOCOL 8 5 1 Datagram Structure 8 5 2 Parameter Formats 9 5 3 Commands Communication Frames 11 5 4 Module Set Up 11 5 5 Calibration 14 5 6 Ma...

Страница 3: ...LITY If any Product furnished hereunder fails to conform to the above warranty OEM s sole and exclusive remedy and PNI s sole and exclusive liability will be at PNI s option to repair replace or credi...

Страница 4: ...nse required to build a 2 axis digital compass from scratch Features include an onboard microprocessor for true plug and play compassing and magnetic field sensing a SPI interface 3 V operation softwa...

Страница 5: ...C per the guidelines in this manual these maximum ratings will not be violated Table 3 2 Module Characteristics1 Parameter Minimum Maximum Typical Supply Voltage VDD 3 0 VDC Idle Current 2 0 2 mA Cont...

Страница 6: ...nt range the gain and resolution can be increased by a factor of 2 by setting the ASIC period select to 4096 When setting higher selects be aware that the ASIC counter can overflow if the field is str...

Страница 7: ...ronization with the host Synchronization issues primarily occur during power up when I O and hardware are initialized This may cause glitches in the clock line which can be interpreted by the V2Xe as...

Страница 8: ...ic distortion contributors in a host system Place the compass in a fixed position then move or energize suspect components while observing the output to determine when they are an influence 4 3 SPI Ha...

Страница 9: ...he host keeps clocking the SPI interface after the V2Xe has completed sending a response the V2Xe will keep sending 0x00 for each byte clocked out In effect the connection is made to act like a half d...

Страница 10: ...s a variable length message depending on the number of parameters Example the command for kSetDataComponents with parameters kHeading and kMagnitude is specified below Sync Flag 0xAA Byte 1 Frame Type...

Страница 11: ...4 bytes are in reverse order LSB first Exponent S Mantissa 3130 2322 0 The value v is determined as if and only if 0 Exponent 255 v 1 S 2 Exponent 127 1 Mantissa Zero is represented by 4 bytes of zero...

Страница 12: ...rs are unsigned 32 bit numbers msb 31 24 23 16 15 8 lsb 7 0 Big Endian lsb 7 0 15 8 23 16 msb 31 24 Little Endian Unsigned 16 Bit Integer UInt16 UInt16 based parameters are unsigned 16 bit numbers Big...

Страница 13: ...esponse to kGetConfig 0x09 kSave Saves the current internal configuration and any new user calibration coefficients to non volatile memory Calibration 0x0A kStartCal Commands the V2Xe to start user ca...

Страница 14: ...y the kSave command must be issued Example To configure the declination the payload would look like Table 5 2 Configuration Identifiers Parameter Config ID Format Values Range Default kDeclination 0x0...

Страница 15: ...heading query command is received from the host If kSampleFreq is set to 0 Hz then X and Y counts are sampled and the heading calculated after a query is received kPeriod Config ID 0x05 This sets the...

Страница 16: ...save internal configurations and user calibration to non volatile memory Internal configurations and user calibration are restored on power up The frame has no payload This is the ONLY command that c...

Страница 17: ...valid samples the reported heading will be 1 00 degree kStartCal frame ID 0x0A This frame commands the module to start a user field calibration The calibration sampling frequency is set with the kCal...

Страница 18: ...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 sen...

Страница 19: ...the raw values Their values are used to calculate the heading kHeading Component ID 5d Provides compass heading calculated from kXCal and kYCal where the heading range is 0 0 to 359 9 kHeading will e...

Страница 20: ...for 0xAA Sync Flag If True push data out If False loop on delay kGetDataResp frame ID 0x05 The response to kGetData is kGetDataResp The specific data fields that will be output ID 1 Value ID 1 etc sho...

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