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