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VN-100 User Manual

1. 4 Quatj1 F4 Calculated attitude as quaternion 8 Quatt2 F4 Calculated attitude as quaternion 12 Quat 3 F4 Calculated attitude as quaternion Scalar component 16 Max Fa Calibrated magnetometer measurement in x axis 20 May Fa Calibrated magnetometer measurement in y axis 24 Maz Fa Calibrated magnetometer measurement in z axis AA www vectornav com 52 102 VN 100 User Manual Byte Offset 0 1 12 Example Serial Read Register Quaternion and Acceleration Quaternion and Acceleration Register ID 11 Firmware v0 1 and up Access Comment Attitude solution and acceleration Size Bytes 28 Response Number Name Format Unit fquatio Ei SSIES Loria aes ce HyHIRIRIA n n N Description Calculated attitude as quaternion Calculated attitude as quaternion Calculated attitude as quaternion Calculated attitude as quaternion Scalar component Calibrated accelerometer measurement in x axis Calibrated accelerometer measurement in y axis Calibrated accelerometer measurement in z axis www vectornav com UMo001 Read Only SVNRRG 11 0 017348 0 000265 0 053568 0 998414 00 003 00 344 09 841 62 53 102 VN 100 User Manual UMO001 7 13 Quaternion and Angular Rates Quaternion Acceleration and Angular Rates Register ID 12 Firmware v0 1 and up Comment Attitude solution and compens
2. ccccccesesseeeeeeeeeeeeeeseeeeeeeees 19 3 3 Synchronizing the VN 100 with other deVICES cccecesseesttettteteeeeeeeees 19 4 www vectornav com 2 102 AA VN 100 User Manual UMO001 34 Synchronizing Multiple VN 100 S iscsesesssniccasvderedeavscectivestecuveredcadseuvecauserdecandeaeneuderwes 19 3 5 Running the VN 100 off an external ClOCK cccccccsssteceessseeecssseeeeceesseeeceessaaeeeeees 20 3 6 Using the VN 100 with external Sensors ccceesesseesseseseeeeeeeeeeeeeeeeeeaees 21 4 Specifications sosicsneuvisoesansssnennenssunnesanaventtagnesseanconnsausastiesunanev ican 23 4 1 Pin out and Electrical Specifications cccccccccccceccceeceecceecceecceeeeeeeceeeeeees 23 4 14 VN 100 Surface Mount Sensor SMT sxssciscessonssevsnasedevsserapencensavvarennsavien seveesoanevandens 23 ADD VN 100 Rugged rected ehiceoecvetcl ovecens eben tose ceebeasti deed gnc ered nsnecdini deep se viecee 26 4 2 Physical Specifications and DIMENSIONS ccceccceccceccceeccecceecceecceeeeeeeeeees 28 4 2 1 VN 100 Surface Mount Sensor sissnssvecisedesvesenasacens sedecavenegavessdevnenvaneracans sedasnenesvaninns 28 4 3 Absolute Maximum Ratings cccccccccsccceeccsecceecceeeceeeceeseeeeseeseeeeeeeeeeeeeees 28 5 Basic Communication ssseesssossossesessssossossesssossessosseessoseesssssse 28 5 1 Serial Interfac ssesoesesaririisteeiere niine ne EEE EEEE EEEE 29 5 2 Checksum CRCOsessreotisoin iaria a a aaao a
3. SYNCIN_TIME Syncin Time SYNCOUT_COUNT SyncOut Counter KA www vectornav com 72 102 VN 100 User Manual UMO001 7 31 2 SerialStatus The SerialStatus field provides a means of tracking real time status information pertaining to the overall state of the sensor measurements and onboard filtering algorithm This information is very useful in situations where action must be taken when certain crucial events happen such as the detection of gyro saturation or magnetic interference As with the SerialCount a typical serial asynchronous message would appear as the following SVNYPR 010 071 000 278 002 026 60 With the SerialStatus field set to one of the non zero values the same asynchronous message would appear instead as SVNYPR 010 071 000 278 002 026 S0000 1F When the SerialStatus field is enabled the status will always be appended to the end of the message just prior to the checksum If both the SerialCount and SerialStatus are enabled then the SerialStatus will be displayed first The counter will be preceded by the S character to distinguish it from the counter field The status consists of 4 hexadecimal characters Table 32 AsyncStatus Value Description 7 31 3 SPICount The SPICount field provides a means of appending a time or counter to the end of all SPI packets The values for each of these counters come directly from the Synchronization Status Register Table 33 SPICount Field Mode Value Descript
4. 16 MagX Fa Calibrated magnetometer measurement in x axis 20 May o m Calibrated magnetometer measurement in y axis 24 Maz Fa Calibrated magnetometer measurement in z axis 28 m s Calibrated accelerometer measurement in x axis 32 m s Calibrated accelerometer measurement in y axis 36 m s Calibrated accelerometer measurement in z axis AA www vectornav com 55 102 VN 100 User Manual UMO001 7 15 Quaternion Acceleration and Angular Rates Byte Offset 0 Quaternion Acceleration and Angular Rates Register ID 14 Firmware v0 1 and up Access Read Only Comment Attitude solution acceleration and compensated angular rates Size Bytes 40 Example Serial Read Register SVNRRG 14 0 017270 0 000926 0 056119 0 998274 00 005 00 332 09 822 Response 0 000738 0 000312 0 002216 76 Number Name Format Unit Description Quat F4 Calculated attitude as quaternion Quat Fa Calculated attitude as quaternion Quat 2 F4 Calculated attitude as quaternion Quat 3 Fa Calculated attitude as quaternion Scalar component Calibrated accelerometer measurement in x axis Calibrated accelerometer measurement in y axis Calibrated accelerometer measurement in z axis Calibrated amp filter bias compensated angular rate in x axis Calibrated amp filter bias compensated angular rate in y axis Calibrated amp filter bias co
5. 7 21 Magnetic Acceleration and Angular Rates Magnetic Acceleration and Angular Rates Register ID 20 Firmware v0 1 and up Access Read Only Comment Magnetic acceleration and compensated angular rates Size Bytes 36 Example Serial Read Register SVNRRG 20 1 0684 0 2578 3 0649 00 005 00 341 09 780 0 000963 0 000840 Response 0 000466 64 Byte Number Offset Name Format Unit Description Max Fa Calibrated magnetometer measurement in x axis Magy Fa Calibrated magnetometer measurement in y axis Maz Fa Calibrated magnetometer measurement in z axis AccelX F4 m s Calibrated accelerometer measurement in x axis Calibrated accelerometer measurement in y axis Calibrated accelerometer measurement in z axis Gyrox F4 rad s Calibrated amp filter bias compensated angular rate in x axis GyroY F4 rad s Calibrated amp filter bias compensated angular rate in y axis Gyroz F4 rad s Calibrated amp filter bias compensated angular rate in z axis n T n gt gt Q O lt T gt oO a OR N n AA www vectornav com 62 102 VN 100 User Manual UMO01 7 22 Magnetic and Gravity Reference Vectors Magnetic and Gravity Reference Vectors Register ID 21 Firmware v0 1 and up Access Read Write Comment Magnetic and gravity reference vectors Size Bytes 24 Example Serial Read Register Respo
6. 7 6 Serial Baud Rate Register Serial Baud Rate RegisterID 5 Firmware v0 1 and up Access Read Write Comment Serial baud rate Size Bytes 4 Example Serial Read Register SVNRRG 05 115200 5D Response Byte Number Offset Name Format Unit Description 0 Baud Rate U4 f _ Serial baud rate Optional The serial port to change the baud rate on 4 Serial Port U1 If this parameter is not provided then the baud rate will be changed for the active serial port This register specifies the baud rate of the serial data bus The table below specifies the associated baud rate achieved when the register is set to one of the values listed in Table 27 The response for this command will be sent after the baud rate is changed Table 27 Baud Rate Settings Acceptable Baud Rates AA www vectornav com 46 102 VN 100 User Manual UMO001 7 7 Async Data Output Type Register Asynchronous Data Output Type Register ID 6 Firmware v0 1 and up Access Read Write Comment Asynchronous data output type Size Bytes 4 Example Serial Read Register Response Byte Number Offset Name Format Unit Description 0 ADOR ae ee Output register n Jo Optional The serial port to change the asynchronous data type 4 Serial Port U1 on If this parameter is not provided then the ADOR will be changed for the active serial port This register controls the type of data that will be asynchronously outputted by the module Wit
7. 8 Quat 2 F4 Calculated attitude as quaternion 12 Quat 3 F4 Calculated attitude as quaternion Scalar component This register contains four values representing the quaternion vector The quaternion provides a redundant nonsingular attitude representation that is well suited for describing arbitrary large rotations The quaternion is a non dimensional 4x1 unit vector with the fourth value as the scalar term The fields of this register are represented with fixed point precision for the serial protocol and 32 bit floating point precision for the SPI protocol This is a read only register All filtering and other mathematical operations performed by the VN 100 are performed using quaternions The quaternion used by the VN 100 has the following form Weegee q 0 e sin q 1 e sin NIS NIS NIS NS E a aa NS q 2 e sin q 3 cos 5 ex Where e is the principal axis and is the principal angle ez KAA www vectornav com 51 102 VN 100 User Manual UMO001 7 11 Quaternion and Magnetic Quaternion and Magnetic RegisterID 10 Firmware v0 1 and up Access Read Only Comment Attitude solution and magnetic Size Bytes 28 Example Serial Read Register Response Byte Number Offset Name Format Unit Description Quat 0 F4 Calculated attitude as quaternion SVNRRG 10 0 017285 0 000569 0 053088 0 998440 1 0641 0 2576 3 0696 6E gt
8. o UMO01 AA User manual VN 100 NN VECTORNAV VN 100 User Manual Firmware v1 1 AA Rev 1 2 8 1 102 VN 100 User Manual UMO001 Table of Contents 1 WAEROGUCEION eessscecesisveschewcesed chessciscectrosnccsesbestewscucsateadevicsiwedesseoesnetes 7 1 1 Product Description sonsasciessucndoesiennscavmaiesdnessacacneribaridspconnsasadivedtinngucdcnunddeetenns 7 1 2 Prod ct Feat res sats cece aa sree en iesi eii p i i iieiea 7 1 3 Surface Mount PACKA BGs cccrspciicecesauiedsnignsarcersiaaenengedaaterausedcelievdecesdiiaewuad dashesaxdelictocdevense 8 1 4 Rugged PA CKA SG sacetisiscccadengscsantaraauenaaind eecatieinneca EE EEEE AEE TREE 8 1 5 Surface Mount Development Mit rec sack sesrateeiiv aise sdcvensceacs decescdv data ghevediancetiemnatacaaneuanane 8 1 6 VN 100 Rugged IMU AHRS Development Kit ccceeccesceseceeeseeeeeeseeceseceaeceeeeeeeeees 9 2 VN 100 Vector Processing Engine cssscssscssscsccssccesceccnsssesees 10 2 OV ORNGW oere EE E EAE A ETE EE E E E eset eeietieeesoes 10 2 2 Components OF the VPEsucnsicontisrmminmencosa ieee aeosormn 10 2 3 Static Factory Calibration icacicwccsumercsimsnsscinrcrannnaseceodmnasmaanmncananaanee 11 2 4 Dynamic Real time Calibration 0 cccccecccceessssececsssseceesesaeeeceeseseeeesssseeeesssaeeeeees 11 2 5 Adaptiv Filtering So css la caidicaied asus hacdamesichadainasanesteuadiumnsjadaaasexadaame a Ea EE 12 2 6 Adaptive TUNNE ceisio nus ncdeendan
9. xv TSS NRST pulse width 29 s f Table 11 Syncin Specifications Specification Min Typical Max Input low level voltage osv f osv Input high level voltage xv TSS Pulse Width f 50s f Table 12 SyncOut Specifications Specification Min Typical Max Output low voltage ov Output high voltage a so Output high to low fall time f 135ns Output low to high rise time _ f Ea OV Output Frequency 1 Hz AA www vectornav com 27 102 VN 100 User Manual UMO001 4 2 Physical Specifications and Dimensions 4 2 1 VN 100 Surface Mount Sensor 4 2 1 1 Footprint Figure 9 VN 100 PCB Footprint 100 DOOOOOS Cos 990 n CI CI CI 868 a Z c 045 m 13 i Yo CI RECHNET L gia j 778 j 910 Measurements are in inches 4 3 Absolute Maximum Ratings Table 13 Absolute Maximum Ratings Specification Max Input Voltage Operating Temperature Storage Temperature 5 Basic Communication The VN 100 module supports two communication interfaces serial and SPI On the serial interface the module communicates over a universal asynchronous receiver transmitter UART and uses ASCII text for its command and data format On the SPI interface the VN 100 module communicates as a slave AA www vectornav com 28 102 VN 100 User Manual UMO001 device on a Serial Peripheral Interface SPI data bus and uses a binary
10. Along with providing calibrated sensor measurements the VN 100 also computes and outputs a real time drift free 3D orientation solution that is continuous over the complete 360 degrees of motion 1 2 Product Features The VN 100 is available in two different configurations in a surface mounted package VN 100 SMT or with an aluminum enclosure VN 100 Rugged The VN 100 Rugged provides a robust precision anodized aluminum clamshell enclosure ensuring precise alignment and calibration while still retaining the smallest possible footprint The VN 100 can be used as either an Inertial Measurement Unit IMU or as an orientation sensor AHRS As an IMU the VN 100 relies on its high quality factory calibration Each individual VN 100 is calibrated to remove errors in 10 onboard sensors caused by scale factor bias and misalignment This digital alignment also ensures that each of the three 3 axis inertial sensors share the same coordinate frame which is important for navigation applications For applications which require a full orientation solution the VN 100 offers an onboard Aerospace grade attitude estimation Kalman filter This algorithm known as the Vector Processing Engine VPE provides a drift free 3D orientatin solution that works in any orientation and is capable of handling both acceleration and magnetic disturbances For more information about the Vector Processing Engine see Section 2 AA www vectornav com 7 102 VN 100 User Man
11. If an invalid register is requested an error code will be returned The error code format is described in Section 6 5 Table 16 Example Read Register Command Example Command Message UART Command SVNRRG 5 46 UART Response SVNRRG 5 9600 65 SPI Command 8 bytes 01 05 00 00 80 25 00 00 shown as hex SPI Response 8 bytes 00 01 05 00 80 25 00 00 shown as hex 6 4 2 Write Register Command This command is used to write data values to a specified register on the VN 100 module see Section 7 for the list of available registers The ID of the register to be written to is the first parameter This is followed by the data values specific to that register Refer to the appropriate register section in Section 6 for this formatting If an invalid register is requested an error code will be returned The error code format is described in Section 6 5 KAA www vectornav com 34 102 VN 100 User Manual UMO001 Table 17 Example Write Register Command Example Command Message UART Command SVNWRG 5 9600 60 UART Response SVNWRG 5 9600 60 SPI Command 8 bytes 02 05 00 00 80 25 00 00 shown as hex SPI Response 8 bytes 00 02 05 00 80 25 00 00 shown as hex 6 4 3 Write Settings Command This command will write the current register settings into non volatile memory Once the settings are stored in non volatile Flash memory the VN 100 module can be power cycled or reset and the register will be reloaded from non volatile m
12. SVNRRG 240 124 642 000 993 000 203 00 009 00 027 00 084 00 000479 Response 00 000522 00 000076 5F Byte Number Offset Name Format Unit Description 0 Calculated attitude heading angle in degrees 4 Calculated attitude pitch angle in degrees 8 RI Fa deg Calculated attitude roll angle in degrees 12 Acceleration estimate in the inertial X axis 16 Acceleration estimate in the inertial Y axis Acceleration estimate in the inertial Z axis Calibrated un compensated angular rate in the body X axis Calibrated un compensated angular rate in the body Y axis Calibrated un compensated angular rate in the body Z axis MP www vectornav com 95 102 VN 100 User Manual UMO001 7 50 Yaw Pitch Roll amp Inertial Calibrated Measurements Register ID 241 Firmware v1 1 and up Access Read Only Attitude solution as yaw pitch roll and IMU calibrated measurements mapped into commenti the inertial coordinate frame using the current attitude solution Size Bytes 48 Example Serial Read Register SVNRRG 241 124 717 000 988 000 216 01 1964 00 2585 02 9721 00 020 Response 00 018 09 743 00 002349 00 002240 00 000445 7F Number Format Byte Offset Name 0 Yaw 4 Pitch Unit Description Calculated attitude heading angle in degrees Calculated attitude pitch angle in degrees Calculated attitude roll angle in degrees Calibrated magnetometer measurement in the inert
13. mS F4 TM nym T D AA www vectornav com 98 102 VN 100 User Manual UMO001 53 Kalman Filter State Vector Kalman Filter State Vector N Register ID 253 Firmware v0 1 and up Access Read Only Comment The state vector for the Kalman Filter Size Bytes 28 Example Serial Read Register Response Byte Number Offset Name Format Unit Description q 0 of quaternion F4 Calculated attitude as quaternion SVNRRG 253 3 239629E 01 4 725538E 01 4 936326E 01 6 542690E 01 7 909242E 02 9 193795E 02 1 185605E 02 39 Dal 4 q 1 of quaternion F4 Calculated attitude as quaternion 8 q 2 of quaternion F4 Calculated attitude as quaternion 12 E ceslenten aoe Calculated attitude as quaternion Scalar component 16 Estimated X axis gyro bias 20 Estimated Y axis gyro bias 24 Estimated Z axis gyro bias www vectornav com 99 102 VN 100 User Manual UMO001 7 54 Kalman Filter Covariance Matrix Diagonal Kalman Filter Covariance Matrix Diagonal Register ID 254 Firmware v0 1 and up Access Read Only Comment The diagonal of the covariance matrix for the Kalman Filter Size Bytes 24 Example Serial Read Register Response Byte Number Offset Name Format Unit Description o Pfoo F4 Variance for X axis vector component of attitude quaternion 4 Pag aa as Variance for Y axis vector component of att
14. 100 when an error event occurs If the send error mode is enabled then a message similar to the one shown below will be sent on the serial bus when an error event occurs SVNERR 03 72 Regardless of the state of the ErrorMode the number of error events is always recorded and is made available in the SysErrors field of the Communication Protocol Status Register Table 37 ErrorMode Description Ignore Error 1 2 Send Error and set ADOR register to OFF 7 31 8 Example Async Messages The following table shows example asynchronous messages with the AsyncCount and the AsyncStatus values appended to the end KA www vectornav com 74 102 VN 100 User Manual UMO001 Example Type Message Async Message with evr 010 071 000 278 002 026 11162704 2F AsyncCount Enabled Async Message with e ypR 010 071 000 278 002 026 0000 1F AsyncStatus Enabled Async Message with AsyncCount and SUNYER OL0O O71 000 278 002 026 11162704 SO0O0 50 AsyncStatus Enabled AA www vectornav com 75 102 VN 100 User Manual 7 32 Register ID Comment Size Bytes Example Serial Read Register Response Byte Offset Name D NumParsedSPIMessages MaxUsageSerialRXBuffer oe NumParsedSerialMessages U4 D ur UMo001 Communication Protocol Status Communication Protocol Status Read Write Contains parameters which allow the timing of the VN 100 to be synchro
15. VN 100 User Manual UMO001 7 3 Hardware Revision Register Register ID 2 Firmware v0 1 and up Access Read Only Comment Hardware revision Size Bytes 4 Example Serial Read Register Response Byte Number Offset Name Format Unit Description O Revision U4 Hardware revision SVNRRG O2 4 69 MP www vectornav com 43 102 VN 100 User Manual UMo001 7 4 Serial Number Register Serial Number Register ID 3 Firmware v0 1 and up Comment Serial Number Size Bytes 12 Example Serial Read Register SVNRRG 03 0672FF574957824887212839 58 Response Access Read Only Byte Number Offset Name Format Unit Description o snfo x4 SNSection 1 8 hexadecimal digits 4 bytes 4 sN x4 SNSection 2 8 hexadecimal digits 4 bytes 8 sni x4 SNSection 3 8 hexadecimal digits 4 bytes www vectornav com 44 102 VN 100 User Manual UMO001 7 5 Firmware Version Register RegisterID 4 Firmware v0 1 and up Access Read Only Comment Firmware version Size Bytes 4 Example Serial Read Register Response Byte Number Offset Name Format Unit Description 0 Major Version u Major release version of firmware 1 MinorVersion ua Minor release version of firmware 2 Build us f Buildnumber 3 Hotfix us Hotfixnumber SVNRRG 04 1 1 98 0 44 MP www vectornav com 45 102 VN 100 User Manual UMO001
16. can also be used to correct for any orientation errors due to mounting the VN 100 on the user s circuit board th The variables X Y Z are a measured parameter such as acceleration in the body reference frame with respect to the VN 100 The variables X Y Z are a measured parameter such as acceleration in the user s frame of reference The reference frame rotation register thus needs to be loaded with the transformation matrix that will transform measurements from the body reference frame of the VN 100 to the desired user frame of reference It is crucial that these two frames of reference be rigidly attached to each other All nine numbers are represented by single precision floating points Y C10 C11 C12 Z C20 C21 C22 i cro C01 C02 U 4 www vectornav com 68 102 VN 100 User Manual 7 28 UMO001 Yaw Pitch Roll Magnetic Acceleration and Angular Rates Yaw Pitch Roll Magnetic Acceleration and Angular Rates Register ID Comment Size Bytes Example Serial Read Register Response Byte Offset Name Yaw Firmware Access 4 fol eg MagX CC C Magy MagzZ_ g 28 27 v0 1 and up Read Only Attitude solution magnetic acceleration and compensated angular rates 48 SVNRRG 27 006 380 000 023 001 953 1 0640 0 2531 3 0614 00 005 00 344 09 758 0 001222 0 000450 0 001218 4F Number Format Unit Description Calculated attitud
17. can be found in Section 2 17 The VPE utilizes the main attitude estimation filter to calculate the time varying gyro bias at each time step By dynamically removing this gyro bias the VPE is able to provide a drift free orientation and angular rate estimate The gyro bias is calculated at all times even during periods of motion and does not rely on the device to be placed in a stationary state for periodic zeroing of the bias KA www vectornav com 11 102 VN 100 User Manual UMO001 2 5 Adaptive Filtering The VPE employs adaptive filtering techniques to significantly reduce the effect of high frequency disturbances in both magnetic and acceleration Prior to entering the attitude filter the magnetic and acceleration measurements are digitally filtered to reduce high frequency components typically caused by electromagnetic interference and vibration The level of filtering applied to the inputs is dynamically altered by the VPE in real time The VPE calculates the minimal amount of digital filtering required in order to achieve specified orientation accuracy and stability requirements By applying only the minimal amount of filtering necessary the VPE reduces the amount of delay added to the input signals For applications that have very strict latency requirements the VPE provides the ability to limit the amount of adaptive filtering performed on each of the input signals For more information on how to adjust the level of adaptive filtering
18. command and data format Both interfaces support the complete command set implemented by the module A general overview of the command format for each interface is given in the next two sections and formatting specific to each command and associated parameters is provided in the protocol and register sections Section 5 amp 6 5 1 Serial Interface On the serial interface the VN 100 uses ASCII text for its command format All commands start with a dollar sign followed by a five character command a comma command specific parameters an asterisk a checksum and a newline character An example command is shown below SVNRRG 11 73 5 2 Checksum CRC The serial interface provides the option for either an 8 bit checksum or a 16 bit CRC In the event neither the checksum nor the CRC is needed they can be turned off by the user 5 2 1 1 8 bit Checksum The 8 bit checksum is an XOR of all bytes between but not including the dollar sign and asterisk All comma delimiters are included in the checksum calculation The resultant checksum is an 8 bit number and is represented in the command as two hexadecimal characters The C function snippet below calculates the correct checksum unsigned char calculateChecksum char command int length unsigned char xor 0 for int i 0 i lt length i A xor unsigned char command i return xor 5 2 1 2 16 bit CRC For cases where the 8 bit checksum doesn t prov
19. inise ERE RE EREE 77 Syne NEA E raei iniia aE REN EEEE EE 77 S nel SkipFaCtOT eserinin renren aranana RE ARETE ARRE OR E ERR 78 SYMCOUtM OA Eies aseaharitareadcdttocsaddioselioudtiesantdssensedediahaunsdunnddsdeuplaedadiaagedeteaiedieeemigusanons 78 SyncOutPolaritY c5 caisntsatdustenacsiauadtdann ebeutiddiaie ectaeis en eaeeaiaens 78 SyncO tSkipFattO asinen iiien E ET EA ARER 78 SyncO tPulseWidth sssini uiia Ea RR a eE r EE a OENE KREE 79 Synchronization Status ssesssnesnnnenrrrnrnsnrerrnnsrnrsnrnrnrnsnnnnnnnsnnrsnnnsnnnss 80 Filter Basic CONtrol ccscusiassstectcadevendeiassnbonsenncnasceiwanscderssdaansantevesdsenpotstactes 81 VPE Basic Control ats ccccavestnceestsduicivseccnecsecsesaaasieiedcabes veatsbsantelsacascetetanctes 82 VPE Magnetometer Basic TUNING s sesecccecseseccecceneeeeeeesaeeeeeeesauaeeeees 83 VPE Magnetometer Advanced TUNing ccsscsssssssssstssseeeeeeeeeeeeeeaees 84 VPE Accelerometer Basic TUNING ccsscssesesssestccstecseceseceeeeeaeseeeeeaes 85 VPE Accelerometer Advanced TUNING c ccsscesssssssssteeeeeeeeseeeeeeeeaees 86 VPE Gyro Basic Tuning csasessanocensvncitaaiednatsniedvavan cawssaneedacnevlanesteseencecvadesssne 87 Filter Status corio e a E e E E T R 88 Filter Startup Gyro BiaS eeneuenunenueensrenrrerrrerrrerrrerrrerrrerrrerrrerrrerrrerreen 89 Magnetometer Basic Calibration Control cccccccccccceeceseessseeseeeeeeeers 90 Magnetometer Calibration St
20. low level voltage osv f o8v Input high level voltage xv f ss Output low voltage owo o Output high voltage 2w 3w 4 1 1 3 VN 100 SMT Serial Peripheral Interface SPI Table 4 Serial I O Specifications Specification Min Typical Max Input low level voltage osv f o8v Input high level voltage xv TSS Output low voltage owo o Output high voltage 2w 3o Clock Frequency MHz 16 MHz Close Rise FallTime _ f 8n 4 1 1 4 VN 100 SMT Reset SynciIn Out and Other General I O Pins Table 5 NRST Specifications Specification Min Typical Max Input low level voltage osv f osv Input high level voltage x f ss NRST pulse width 20ms Table 6 Syncin Specifications Specification Min Typical IER Input low level voltage osv f o8v Input high level voltage xv TSS Pulse Width f 500s f Table 7 SyncOut Specifications Specification Min Typical Max Output low voltage owo o Output high voltage S 2w 3o Output high to low fall time pT 125 ns Outputlowtohighrisetime _ f 125ns Output Frequency 1 Hz l 200 Hz KA www vectornav com 25 102 VN 100 User Manual UMO001 4 1 2 VN 100 Rugged Table 8 VN 100 Rugged Pin Assignments Pin Pin Name Description Output signal used for synchronization purposes Software configurable SYNC_OUT E to pulse when ADC IMU or attitude mea
21. magnetometer sensor and also subsequently used in the attitude filter Controls how quickly the hard soft iron solution is allowed to converge onto a new solution The slower the convergence the more accurate the estimate of the hard soft iron solution A quicker convergence will provide a less accurate estimate of the hard soft 2 ConvergeRate U1 iron parameters but for applications where the hard soft iron changes rapidly may provide a more accurate attitude estimate Range 1to 5 1 Solution converges slowly over approximately 60 90 seconds 5 Solution converges rapidly over approximately 15 20 seconds Table 52 HSI_Mode Field Mode Value Description HS _OFF o Real time hard soft iron calibration algorithm is turned off Runs the real time hard soft iron calibration The algorithm will continue using its existing HSI_RUN 1 solution The algorithm can be started and stopped at any time by switching between the HSI_OFF and HSI_RUN state Table 53 HSI_Output Field Mode Value Description CAL OFF o The raw un processed magnetic measurements CAL MANUAL 1 The magnetometer measurements are compensated for hard soft iron using the user register Section 7 24 CAL AUTO 2 The magnetometer measurements are compensated for hard soft iron using the calculated register Section 0 a KA www vectornav com 90 102 VN 100 User Manual UMO001 7 45 Magnetometer Calibration Status Reg
22. precision floating point and single precision fixed point In order to conserve bandwidth each variable in the register has associated with it either a floating or fixed point representation Any time this variable is accessed using a read write register command or as Async output the variable will always use its associated data format 6 2 Single Precision Floating Points Single precision floating point numbers are represented with 7 significant digits and a 2 digit exponent Both the sign of the number and exponent are provided The decimal point will always follow the first significant digit An E will separate the significant digits from the exponential digits Below are some samples of correct single precision floating point numbers Single Precision Floating Point Number Examples 9 999999E 99 7 344409E 05 1 234567E 01 4 893203E 00 6 3 Fixed Point Numbers The fixed point representation consists of a specified number of digits to the left and right of a fixed decimal point The registers that use fixed point representation and their associated formatting are listed below It is important to note that all numeric calculations onboard the VN 100 are performed with 32 bit IEEE floating point numbers For the sake of simplifying the output stream some of these numbers are displayed in ASCII as fixed point as described below Table 14 Floating Point Representation Variable Type Fixed Floating Register ID s Prin
23. see Section 2 16 2 6 Adaptive Tuning Kalman filters employ coefficients that specify the uncertainty in the input measurements which are typically used as tuning parameters to adjust the behavior of the filter Normally these tuning parameters have to be adjusted by the engineer to provide adequate performance for a given application This tuning process can be ad hoc time consuming and application dependent The VPE employs adaptive tuning logic which provides on line estimation of the uncertainty of each of the input signals during operation This uncertainty is then applied directly to the onboard attitude estimation Kalman filter to correctly account for the uncertainty of the inputs The adaptive tuning reduces the need for manual filter tuning For more information on how to adjust the level of adaptive tuning performed by the VPE see Section 2 15 2 7 Attitude Estimation The orientation and angular rate are calculated using a quaternion based Extended Kalman Filter The estimation algorithm employs quaternion math to eliminate the problem of gimbal lock allowing the device to provide consistent and stable output in any orientation Along with estimating the orientation the filter also estimates the time varying gyro bias This provides a drift free orientation and angular rate estimate even during periods of sustained motion The attitude is estimated using the vector measurements from both the magnetometer and accelerometers The m
24. v0 1 and up Access Read Write Comment Asynchronous data output frequency Size Bytes 4 Example Serial Read Register SVNRRG O7 50 5D Response Byte Number Offset Name Format Unit Description 0 ADOF Output frequency Optional The serial port to change the asynchronous data type 4 Serial Port U1 frequency on If this parameter is not provided then the ADOF will be changed for the active serial port Table 29 ADOR Data Rates Acceptable Data Rates Hz AA www vectornav com 49 102 VN 100 User Manual UMO001 7 9 Attitude Yaw Pitch Roll Format Register ID 8 Firmware v0 1 and up Access Read Only Comment Attitude solution as yaw pitch and roll in degrees Size Bytes 12 Example Serial Read Register SVNRRG 8 006 271 000 031 002 000 66 Response Byte Number Offset Name Format Unit Description 0 Yaw angle heading 4 Pitch angle 8 Rol Fa deg Roll angle MP www vectornav com 50 102 VN 100 User Manual UMO001 7 10 Attitude Quaternion Register ID 9 Firmware v0 1 and up Access Read Only Comment Attitude solution as a quaternion Size Bytes 16 Example Serial Read Register Response Byte Number Offset Name Format Unit Description SVNRRG 9 0 017386 0 000303 0 055490 0 998308 4F o Quatjo F4 Calculated attitude as quaternion 4 Quatj1 F4 Calculated attitude as quaternion
25. 14 Quaternion Magnetic and Acceleration c ccccccceccceeceseessseeseeeeeeees 55 7 15 Quaternion Acceleration and Angular Rates ccccccccccsessssseeeeeeeeeeees 56 7 16 Quaternion Magnetic Acceleration and Angular Rates essees 57 7 17 Attitude Directional Cosine Orientation Matrix ccccccccccccceeeeeeeeeees 58 7 18 Magnetic Measurements ccssssssscceccceccceceesssseceecececsseaeassesseseseeeess 59 7 19 Acceleration Measurements ccccccccccccccssssssssteeeeceeeeeesesesssneeeeeeeeeeeees 60 7 20 Angular Rate MEaSUreMent cccccccccccccceccceecceccceeceeeceeeceeeceeeeeeeeeeeeeses 61 7 21 Magnetic Acceleration and Angular Rates ccccccccceeceeeessseeeeeeeeeeees 62 7 22 Magnetic and Gravity Reference VECtOIs cccccccccccceeceecceecceecceeeeeeeeeees 63 7 23 Filter Measurements Variance ParaMeters ccccccccccccccesssssstteeeeeeeeeeeees 64 7 24 Magnetic Hard Soft Iron Compensation Parameters cccccccccccceeeeeees 65 7 25 Filter Active TUNING Parameters cecccecccccccecccecceeeceeeceeceeeeceeeeeeeeeeeeees 66 7 26 Accelerometer COMPENSATION cccccccccccecccecccecceecceeeceeeceeeeeeeeeeeeeeeeees 67 7 27 Reference Frame Rotation cccsccccccccccccsssssssseeeeeceeeeeesssesseneeeeeeeeeeeees 68 7 28 Yaw Pitch Roll Magnetic Acceleration and Angular Rates 69 7 29 Accelerometer Gain sessie aieea vacsndndsecseunceedinss 70 KA www vectornav co
26. 6 4 6 Reset Command This command will reset the module There are no parameters required for this command The module will first respond to the command and will then perform a reset Upon a reset all registers will be reloaded with the values saved in non volatile memory If no values are stored in non volatile memory then the device will default to factory settings Also upon reset the VN 100 will re initialize its Kalman filter thus the filter will take a few seconds to completely converge on the correct attitude and correct for gyro bias This command is equivalent in functionality to the hardware reset performed by pulling pin 21 low Table 21 Example Reset Command Example Command Message UART Command UART Response SPI Command 8 bytes 06 00 00 00 00 00 00 00 shown as hex SPI Response 8 bytes 00 06 00 00 00 00 00 00 shown as hex 6 4 7 Known Magnetic Disturbance Command This command is used to notify the VN 100 that a magnetic disturbance is present When the VN 100 receives this command it will tune out the magnetometer and will pause the current hard soft iron calibration if it is enabled A single parameter is provided to tell the VN 100 whether the disturbance is present or not O0 No Disturbance is present 1 Disturbance is present Table 22 Example Magnetic Disturbance Command Example Command Message UART Command SVNKMD 1 47 UART Response SVNKMD 1 47 SPI Command 8 bytes 08 01 00 00 00 00 00 00 s
27. 662 0 2537 3 0664 00 018 00 323 Response 09 839 0 017771 0 032381 0 004126 25 5 5B Byte Number Offset Name Format Unit Description Yaw Calculated attitude heading angle in degrees 4 Calculated attitude pitch angle in degrees 8 Rol F4 deg Calculated attitude roll angle in degrees 12 Max o m ees Calibrated magnetometer measurement in x axis 16 Magy Fa Calibrated magnetometer measurement in y axis 20 Maz ti m Calibrated magnetometer measurement in z axis 24 Calibrated accelerometer measurement in x axis 28 Calibrated accelerometer measurement in y axis 32 Calibrated accelerometer measurement in z axis 36 Calibrated un compensated angular rate in x axis 40 Calibrated un compensated angular rate in y axis 44 Calibrated un compensated angular rate in z axis 48 Calibrated temperature in degrees Celsius AA www vectornav com 71 102 VN 100 User Manual UMO001 7 31 Communication Protocol Control Register ID 30 Firmware v1 1 and up Access Read Write Contains parameters that control settings relating to the communication protocol used to communicate with the VN 100 Comment Size Bytes 7 Example Serial Read Register Response Byte Number SVNRRG 30 0 0 0 0 1 0 1 6C Offset Name Format Unit Description cenaicaune Pour Provides the ability to append a counter to the end of the serial asynch
28. Error Codes Error Name Description If this error occurs then the firmware on the chip has experienced a hard fault exception To recover from this error the processor will force Hard Fault 1 e j i a restart and a discontinuity will occur in the serial output The processor will restart within 50ms of a hard fault error The processor s serial input buffer has experienced an overflow The processor has a 256 character input buffer Serial Buffer Overflow Invalid Checksum The checksum for the received command was invalid Invalid Command The user has requested an invalid command Not Enough Parameters 5 The user did not supply the minimum number of required parameters for the requested command Too Many Parameters 6 The user supplied too many parameters for the requested command Invalid Parameter The user supplied a parameter for the requested command which was AA www vectornav com 37 102 VN 100 User Manual UMO001 Sh ae Invalid Register 8 An invalid register was specified Unauthorized Access om The user does not have permission to write to this register A watchdog reset has occurred In the event of a non recoverable error Watchdog Reset 10 x Sete the internal watchdog will reset the processor within 50ms of the error Gu nee ierorenie 11 The output buffer has experienced an overflow The processor has a 2048 character output buffer PTO EEI EE 12 The baud rate is not high enough to support the requested asyn
29. MU Mode SVNWRG 32 0 0 0 0 2 0 0 500000 0 5C 02 20 00 00 00 00 00 00 00 00 00 00 02 00 00 00 00 07 A1 20 00 00 00 00 2 Read the IMU data using Register 252 Section 7 52 This register provides the calibrated magnetometer accelerometer and un compensated angular rate measurements Interface Read Register IMU Data SVNRRG 252 46 01 FC 00 00 For information on how to parse the response to this read register command see Section 7 52 KA www vectornav com 18 102 VN 100 User Manual UMO001 3 2 Using the VN 100 as an Orientation Sensor The VN 100 can be used as either an Inertial Measurement Unit and orientation sensor or both After capturing new IMU measurements the VN 100 immediately begins computing a new attitude solution orientation using its onboard Kalman filter The attitude is provided either as Euler angles a quaternion or a directional cosine matrix Below are the registers that are commonly used when the VN 100 is used as an orientation sensor Register Register Name ADOR ID ADOR Name 8 Yaw Pitch Roll 9 Quaternion o S iyi Directional Cosine Matrix SSS Sess Yaw Pitch Roll and IMU Data Quaternion and IMU Data ee ce The VN 100 offers a SyncOut line that can be software configured to trigger either when the IMU or the attitude measurements are available The device defaults to trigger when the attitude information is available O ll Set the Filter Operational Mode The filte
30. Processing Engine 2 2 Components of the VPE The Vector Processing Engine VPE provides a complete embedded sensor fusion framework capable of estimating the orientation and angular rate of an object in real world environments where both magnetic and acceleration disturbances are present The VPE combines a collection of logic and filter building blocks into a single software package minimizing the additional processing necessary by the end user to obtain an accurate attitude estimate The overall operation of the VPE can be divided into 5 distinct stages Static Factory Calibration Dynamic Calibration Adaptive Filtering Adaptive Tuning Attitude Estimation E a a a NA www vectornav com 10 102 VN 100 User Manual UMO001 2 3 Static Factory Calibration During the static calibration stage each of the ten sensors 3 axis magnetometer 3 axis accelerometer 3 axis gyro and temperature sensor are digitally compensated to eliminate the errors due to scale factor axis misalignment biases and temperature sensitivity For the gyros sensitivity to acceleration is also taken into account Each VectorNav sensor is individually calibrated in temperature controlled robotic calibration stands at our factory to determine each sensor s unique calibration coefficients Each sensor is subjected to precisely known rotations and orientations across the specified performance temperature range The data collected from these tests is used at the fa
31. UMO01 Please Read Carefully Information in this document is provided solely in connection with VectorNav products VectorNav Technologies VectorNav reserves the right to make changes corrections modifications or improvements to this document and the products and services described herein at any time without notice All VectorNav products are sold pursuant of VectorNav terms and conditions of sale No license to any intellectual property expressed or implied is granted under this document If any part of this document refers to any third party products or services it shall not be deemed a license grant by VectorNav for the use of such third party products or services or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein Information in this document supersedes and replaces all information previously supplied The VectorNav logo is a registered trademark of VectorNav Technologies All other names are the property of their respective owners 2009 VectorNav Technologies All rights reserved AA www vectornav com 102 102
32. absolute heading Since this mode assumes that the Earth s magnetic field is the only long term magnetic field present it cannot handle constant long term magnetic disturbances which are of the same order of magnitude as the Earth s magnetic field and cannot be compensated for by performing a hard soft iron calibration From the sensor s perspective a constant long term magnetic disturbance will be indistinguishable from the contribution due to the Earth s magnetic field and as such if present it will inevitably result in a loss of heading accuracy Absolute Heading Mode Advantages e Provides short term magnetic disturbance rejection while maintaining absolute tracking of the heading relative to the fixed Earth Absolute Heading Mode Disadvantages e ifthe magnetic field changes direction relative to the fixed Earth then its direction will need to be updated using the reference vector register in order to maintain an accurate heading reference e Hard Soft iron distortions that are not properly accounted for will induce heading errors proportional to the magnitude of the hard soft iron distortion In some cases this could be as high as 30 40 degrees 2 10 Relative Heading Mode In Relative Heading mode the VPE makes no assumptions as to the long term stability of the magnetic field present In this mode the VPE will attempt to extract what information it reasonably can from the magnetic measurements in order to maintain an accurate e
33. agnetometers can be used in either 2D or 3D mode In 2D mode the magnetometer will only affect the estimated heading and the pitch and roll will only be determined by the output of the accelerometer In 3D mode the magnetometer input is allowed to affect the full attitude solution For applications where the magnetic field is well defined and free of any un modeled disturbances operating in 3D mode will in theory provide the highest level of orientation accuracy For most applications however operating with the magnetometer in 2D mode provides the best overall accuracy due to the inherent uncertainty and variability in the local magnetic field For more information on the settings pertaining to the Attitude Estimation algorithm see Section 7 35 2 8 VPE Magnetic Heading Modes The VectorNav VPU provides three separate heading modes Each mode controls how the VPE interprets the magnetic measurements to estimate the heading angle The three modes are described in detail in the following sections KA www vectornav com 12 102 VN 100 User Manual UMO001 2 9 Absolute Heading Mode In Absolute Heading Mode the VPE will assume that the principal long term DC component of the measured magnetic field is directly related to the earth s magnetic field As such only short term magnetic disturbances will be tuned out This mode is ideal for applications that are free from low frequency less than 1Hz magnetic disturbances and or require tracking of an
34. atakai 29 5 3 SPI interface mcii rnsiiei annii na a e aa E aai aiin Ea ER 30 6 Communication Protocol ssssseessssesssesosssssossssessssssossesossssssssss 33 6 1 Numeric Formats aioe cctsrexvcenvcedaceocvatnennciennsesdwarsundenteubaeweunaineneneecunedbeunddeds 33 6 2 Single Precision Floating Points c cccsccsssessesssessssesseeseseseeeseeeseeeees 33 6 3 Fixed Point NUMberS ssesssssesssssssssssesererrrrsssssrserrrrrsrsssessrrresrsrssssserereeeneeesse 33 6 4 System COMMMAIIG Scasperccthan census iain heneraing Aussetecetnacaensandees teins tbo uenansnneiads 33 6 4 1 Read Register Command srera aE A A EnS 34 6 4 2 Write Register Command sciatica caesar acy nad nade shh cvadeaudemmdnadinepeeudeueeeubeiceneientenaes 34 6 4 3 Write Settings Command ssssscepisieten scivnnhaiiesenssnanedconannvaisonasaadua sanhenmamniiananawiadearaxeniany 35 6 4 4 Restore Factory Settings Command cscccccccccsssssssseeeeceeeeeeseseseeeeeeeeseeesesseaeeas 35 6 4 5 Tare COMMMANG seinien re anie e a a a a aa aaae 35 6 4 6 Reset COMMANA sesiis ennet aer a iaaa atasak 36 6 4 7 Known Magnetic Disturbance COMMANG cscceesecessseceesseeeeeseeessseeessseeeesaeees 36 6 4 8 Known Acceleration Disturbance COMMANGA cceeeececesceceeeeeeeeeeeceeeeetnneeeenaeees 37 6 4 9 Set Gyro Bias Command sipccsaceiiciceooddovderedslldascahedesaagatacasbansedasasduniwsangcaecesgobacecbendeacdes 37 6 5 System Error Codes saxiiiniianismmenesox
35. ated angular rates Size Bytes 28 Example Serial Read Register SVNRRG 12 0 017030 0 000634 0 055279 0 998326 0 000748 0 001867 Response 0 001236 6B Byte Number Offset Name Format Unit Description 0 Quat 0 F4 Calculated attitude as quaternion Access Read Only 4 Quat 1 F4 Calculated attitude as quaternion 8 Quat 2 F4 Calculated attitude as quaternion 12 Quat 3 F4 Calculated attitude as quaternion Scalar component Calibrated amp filter bias compensated angular rate in x axis 20 Calibrated amp filter bias compensated angular rate in y axis 24 Calibrated amp filter bias compensated angular rate in z axis AA www vectornav com 54 102 VN 100 User Manual UMO001 7 14 Quaternion Magnetic and Acceleration Quaternion Magnetic and Acceleration Register ID 13 Firmware v0 1 and up Comment Attitude solution magnetic and acceleration Size Bytes 40 Example Serial Read Register SVNRRG 13 0 017198 0 000737 0 054042 0 998390 1 0670 Response 0 2502 3 0567 00 041 00 313 09 867 77 Byte Number Offset Name Format Unit Description Access Read Only o Quatjo F4 Calculated attitude as quaternion 4 Quatti F4 Calculated attitude as quaternion 8 Quat 2 F4 Calculated attitude as quaternion 12 Quat 3 F4 Calculated attitude as quaternion Scalar component
36. atus ccccccsssessessssesssssesessesseeeseeeees 91 www vectornav com 5 102 VN 100 User Manual UMO001 7 46 Calculated Magnetometer Calibration ccsssssecceeeeeeeeeeeeseeeseeeeeeeens 92 7 47 Indoor Heading Mode Control ccccccccccsccseeccseeceeccsecceceseeeeeeeeeesseeeeees 93 7 48 Yaw Pitch Roll True Body Acceleration and Angular Rates 94 7 49 Yaw Pitch Roll True Inertial Acceleration and Angular Rates 95 7 50 Yaw Pitch Roll amp Inertial Calibrated Measurements 96 7 51 Raw Voltage Measurements ccccccceccceeccecceecccecceeeeeeeceeeeeeeceeeeeeeeeeeeees 97 7 52 Calibrated IMU Measurements ccccccccsesssssseeeeeceeeeeesesesssneeaeeeeeeeeees 98 7 53 Kalman Filter State V Ctor cccsccccccccecccssssssnneeeeceeeecessessennneeeeeeeeeeees 99 7 54 Kalman Filter Covariance Matrix Diagonal c0cccceeeeeeeeeeeeeeeeeees 100 8 System Registers Default Factory State cccscccseecsseceeees 101 RA www vectornav com 6 102 VN 100 User Manual UMO001 1 Introduction 1 1 Product Description The VN 100 is a miniature surface mount high performance Inertial Measurement Unit IMU and Attitude Heading Reference System AHRS Incorporating the latest solid state MEMS sensor technology the VN 100 combines 3 axis accelerometers 3 axis gyros and 3 axis magnetic sensors as well as a 32 bit processor into a miniature surface mount module
37. bances lasting less than a Yes Yes few seconds es than a few seconds Maintain accurate heading relative to true North over long periods of time Accuracy depends upon recovery rate settings See Section 7 47 for more information 2 13 VPE Adaptive Filtering and Tuning Settings The VPE actively employs both adaptive filtering and adaptive tuning techniques to enhance performance in conditions of dynamic motion and magnetic and acceleration disturbances The VPE provides the ability to modify the amount of adaptive filtering and tuning applied on both the magnetometer and the accelerometer In many cases the VPE can be used as is without any need to adjust these settings For some applications higher performance can be obtained by adjusting the amount of adaptive filtering and tuning performed on the inputs For both the magnetometer and the accelerometer the following settings are provided 2 14 Static Measurement Uncertainty The static gain adjusts the level of uncertainty associated with either the magnetic or acceleration measurement when no disturbances are present The level of uncertainty associated with the measurement will directly influence the accuracy of the estimated attitude solution The level of uncertainty in the measurement will also determine how quickly the attitude filter will correct for errors in the attitude when they are observed The lower the uncertainty the quicker it will correct for observed errors e Th
38. ble 41 SyncOutPolarity WELT Description oe Negative Pulse Positive Pulse 7 33 6 SyncOutSkipFactor The SyncOutSkipFactor defines how many times the sync out event should be skipped before actually triggering the SyncOut pin KA www vectornav com 78 102 VN 100 User Manual UMO01 7 33 7 SyncOutPulseWidth The SyncOutPulseWidth field controls the desired width of the SyncOut pulse The default value is 500 000 ns 0 5 ms AA www vectornav com 79 102 VN 100 User Manual UMO001 7 34 Synchronization Status Synchronization Status Example Serial Read Register ID 33 Firmware v1 1 and up Access Read Write Comment Contains status parameters that pertaining to the communication synchronization features Size Bytes 12 SVNRRG 33 2552498 0 0 6A Register Response Byte Number Offset Name Format Unit Description Keeps track of the number of times that the Syncln trigger even has occured This register can be used to correlate the attitude to an event on an external system such as a camera or GPS 0 SyncInCount U4 It is also possible to have the value of this register appended to each 4 8 asynchronous data packet on the serial bus This can be done by setting the AsyncStatus field in the Communication Protocol register to 1 This field is writable to allow for initialization or clearing Keeps track of the amount of time that has elapsed since the last Syncin trigger event If the Syncin
39. ccess Magnetometer measurements 12 SVNRRG 17 1 0647 0 2498 3 0628 66 Number Format Unit Description Max Fa Calibrated magnetometer measurement in x axis e E Maz Fa Calibrated magnetometer measurement in z axis www vectornav com UMo001 Read Only 59 102 VN 100 User Manual UMO001 7 19 Acceleration Measurements Acceleration Measurements Register ID 18 Firmware v0 1 and up Access Read Only Comment Acceleration measurements Size Bytes 12 Example Serial Read Register Response Byte Number Offset Name Format Unit Description 0 Calibrated accelerometer measurement in x axis 4 Calibrated accelerometer measurement in y axis 8 Calibrated accelerometer measurement in z axis SVNRRG 18 00 013 00 354 09 801 65 MP www vectornav com 60 102 VN 100 User Manual UMO001 7 20 Angular Rate Measurements Angular Rate Measurements v0 1 and up Access Read Only Register ID 19 Firmware Comment Compensated angular rates Size Bytes 12 Example Serial Read Register lt prc 19 0 002112 0 000362 0 000876 6C Response Byte Number Offset Name Format Unit Description 0 Calibrated amp filter bias compensated angular rate in x axis 4 Calibrated amp filter bias compensated angular rate in y axis 8 Calibrated amp filter bias compensated angular rate in z axis www vectornav com 61 102 VN 100 User Manual UMO001
40. chronous data output at the requested data rate 7 System Registers The VN 100 module contains a collection of registers used for configuring the module and accessing the data it produces These registers may be read or written to using the Read Register and Write Register commands Sections 6 4 1 and 6 4 2 When the module is rebooted or power cycled values written to the registers will revert back to their previous values unless a Write Settings command has been issued Section 6 4 3 to save the registers to non volatile memory Table 26 provides a quick reference for all of the registers and their associated properties The second column lists the Access ID which is used to identify a specific register The third column indicates the width of the register in bytes relevant only in SPI mode and the last column provides the section number where a more detailed explanation of the register may be found Each register may be read or written to using either serial or SPI communication modes The specific register sections that follow describe the format used by each communication mode AA www vectornav com 38 102 VN 100 User Manual UMO001 Table 26 System Registers Register Name AccessID Width bytes Section User Tag N Model Number T2 Hardware Revision 7 3 Serial Number 7 4 Firmware Version 7 5 Serial Baud Rate 7 6 Asynchronous Data Output Type 7 7 Asynchronous Data Output Frequency 7 8 Attitude Yaw Pitch Roll 7 9 Attitud
41. ctory to calculate the unique calibration coefficients for each individual sensor and these calibration coefficients are permanently stored in flash During operation at each time step after the raw measurements are collected from the sensors the calibration coefficients are digitally applied to compensate for the known systematic errors measured during the factory calibration This static calibration is automatically applied at each time step by the VN 100 and no additional processing is required by the end user Figure 2 Sensor Calibration e z aP 2 4 Dynamic Real time Calibration Some of the sensors have calibration parameters that are time variant or are altered when the sensor is installed into its intended application The magnetometer for example experiences changes to its apparent scale and bias due to the effect of nearby ferrous materials which alter the measured local magnetic field If not properly accounted for these distortions can result in a significant loss of heading accuracy Traditionally hard soft iron distortions are accounted for using off line post processing techniques The VPE utilizes a separate optional Kalman Filter running in the background to estimate on line the hard soft iron distortions This eliminates the need for off line data processing and allows the VPE to dynamically adapt to potentially varying magnetic conditions More information about the operation of the automatic hard soft iron calibration
42. d in the magnetometer BaseTuningY F4 0 10 Y axis when no disturbances are present A larger number provides better heading accuracy but with more sensitivity to magnetic interference SVNRRG 36 5 5 5 3 3 3 4 4 4 68 4 Base Magnetic Tuning Z Axis 0 10 This sets the level of confidence placed in the magnetometer 8 Z axis when no disturbances are present A larger number provides better heading accuracy but with more sensitivity to magnetic interference 12 Level of adaptive tuning for X Axis 16 Level of adaptive tuning for Y Axis 20 Level of adaptive tuning for Z Axis 24 Level of adaptive filtering for X Axis 28 Level of adaptive filtering for Y Axis 32 Level of adaptive filtering for Z Axis AA www vectornav com 83 102 VN 100 User Manual UMO01 7 38 VPEMagnetometer Advanced Tuning Register ID 37 Firmware v1 1 and up Access Read Write Comment Provides advanced control of the adaptive filtering and tuning for the magnetometer Size Bytes 36 Example Serial Read Register Response Byte Number Offset Name Format Min Max Description MinFilteringX 0 10 Minimum allowed level of filtering for X Axis MinFilteringY 0 10 Minimum allowed level of filtering for Y Axis SVNRRG 37 0 10 0 10 0 10 1 2 1000 68 8 Minimum allowed level of filtering for Z Axis 12 Maximum allowed level of filtering for X Axis 16 Maximum allowed level of filtering for Y Axis 20 Maximum al
43. e Quaternion 7 10 Quaternion and Magnetic 7 11 7 12 7 13 7 14 7 15 7 16 7 17 l 7 18 7 19 7 20 7 21 7 22 7 23 7 24 7 25 7 26 7 27 7 28 7 29 7 30 7 31 7 32 7 33 7 34 KA www vectornav com 39 102 VN 100 User Manual UMO001 Register Name AccessID Width bytes Section Yaw Pitch Roll True Body Acceleration amp Angular Rate 239 Yaw Pitch Roll True Inertial Acceleration amp Angular Rate 240 Yaw Pitch Roll amp Inertial Calibrated Measurements 241 251 252 253 254 AA www vectornav com 40 102 VN 100 User Manual UMO001 7 1 User Tag Register Register ID 0 Firmware v1 1 and up Access Read Write User assigned tag register Any values can be assigned to this register They will be stored to flash upon issuing a write settings command Comment Size Bytes 20 Example Serial Read Register Response Byte Number SVNRRG OO SENSOR_A14 52 Offset Name Format Unit Description o Tag c20 User defined tag register Up to 20 bytes or characters MP www vectornav com 41 102 VN 100 User Manual Model Number Register UMo001 Model Number 7 2 Register ID Comment Size Bytes Example Serial Read Register Response Byte Offset Name 1 Firmware Model Number 24 SVNRRG 01 VN 100 5A Number Format Unit Description v0 1 and up 0 Product Name c24 Product name 24 characters www vectornav com Access Read Only 42 102
44. e heading angle in degrees Calculated attitude pitch angle in degrees Calculated attitude roll angle in degrees Calibrated magnetometer measurement in x axis Calibrated magnetometer measurement in y axis Calibrated magnetometer measurement in z axis Calibrated accelerometer measurement in x axis Calibrated accelerometer measurement in y axis Calibrated accelerometer measurement in z axis Calibrated amp filter bias compensated angular rate in x axis Calibrated amp filter bias compensated angular rate in y axis Calibrated amp filter bias compensated angular rate in z axis n J gt n By N iS N www vectornav com 69 102 VN 100 User Manual UMO001 7 29 Accelerometer Gain Accelerometer Gain Register ID 28 Firmware v0 1 to v0 8 Access Read Write Comment Controls the accelerometer gain Size Bytes 4 Example Serial Read Register Response Byte Number Offset Name Format Unit Description O Accelgain U4 Accelerometer Gain SVNRRG 28 0 65 Table 30 Accelerometer Gain Register Value Accelerometer Gain a ee 7 www vectornav com 70 102 VN 100 User Manual UMO01 7 30 Yaw Pitch Roll amp Calibrated Measurements Register ID 29 Firmware v0 1 and up Access Read Only Comment Attitude solution as yaw pitch roll and IMU calibrated measurements Size Bytes 52 Example Serial Read Register SVNRRG 29 006 536 000 031 001 968 1 0
45. e of edge the signal is set to trigger on The factory default state is to trigger on a rising edge Table 39 SynciInEdge Mode Value Description oo Trigger on rising edge Trigger on falling edge 7 33 3 SyncinSkipFactor The SynclnSkipFactor defines how many times trigger edges defined by SynclnEdge should occur prior to triggering a Syncin event The action performed on a Syncin event is determined by the Syncin mode As an example if the SynclInSkipFactor was set to 4 and a 1 kHz signal was attached to the Syncin pin then the Syncin event would only occur at 200 Hz 7 33 4 SyncOutMode The SyncOutMode register controls the behavior of the SyncOut pin If this is set to ADC then the SyncOut will start the pulse when the internal ADC loop starts This mode is used to make a sensor the Master in a multi sensor network array If this is set to IMU mode then the pulse will start when IMU measurements become available If this is set to AHRS mode then the pulse will start when attitude measurements are made available Changes to this register take effect immediately Table 40 SyncOutMode Mode Value Description Trigger at start of ADC sampling IMU 2 Trigger when IMU measurements are available AHRS Trigger when attitude measurements are available 7 33 5 SyncOutPolarity The SyncOutPolarity register controls the polarity of the output pulse on the SyncOut pin Changes to this register take effect immediately Ta
46. e this will be given in hexadecimal representation 4 Standard deviation of uncertainty in yaw estimate 8 Standard deviation of uncertainty in pitch estimate 12 Standard deviation of uncertainty in roll estimate 16 Maximum uncertainty in the current gyro bias estimate 20 MagUncertainty F4 Maximum uncertainty in the current magnetic measurement 24 Maximum uncertainty in the current acceleration measurement Table 50 SolutionStatus Field 2 bytes Bit Offset me AttitudeQuality o 2bits Provides an indication of the quality of the attitude solution GyroSaturation 2 ee ie e At least one gyro axis is currently saturated 5 Filter is in the process of recovering from a gyro saturation GyroSaturationRecovery oa abit yee P 8 8y MagDCDisturbance 4 1bit Astrong magnetic DC disturbance has been detected MagACDisturbance 5 1bit Astrongmagnetic AC disturbance has been detected MagSaturation 6 1bit Atleast one magnetometer axis is currently saturated AccDCDisturbance 7 1bit Astrong acceleration DC disturbance has been detected AccACDisturbance 8 1bit Astrongacceleration AC disturbance has been detected AccSaturation 9 1bit Atleast one magnetometer axis is currently saturated UsingAutoHSISolution 10 1bit The automatic hard soft iron calibration is being used KnownMagDisturbancePresent 11 1bit Aknown ma
47. ed for tare until at least 5 ms after a power on or reset Internally held low with 10k resistor Time synchronization output signal See section 7 33 for more details 3 2 5 5V input Leave high for normal operation Pull low to enter sleep mode Internally pulled high with pull up resistor Serial UART 1 data output sensor Serial UART 1 data input sensor Reserved for future use Leave pin floating Reserved for future use For backwards compatibility with older hardware revisions this pin can be configured in software to operate as the time synchronization input signal For new designs it is recommended that SYNC_IN pin 22 is used instead See Section 7 33 for more details SPI clock SPI input 19 SPI_MISO SPI output Used to reprogram the module Must be left floating or set to low for normal operation Pull high on startup to set the chip in reprogram mode Internally held low with 10k resistor Microcontroller reset line Pull low for gt 20us to reset MCU Internally 21 NRST pulled high with 10k 2 23 24 25 26 27 28 GND 29 30 cnp 20 REPRGM KA www vectornav com 24 102 VN 100 User Manual UMO001 4 1 1 1 VN 100 SMT Power Supply The minimum operating supply voltage is 3 2V and the absolute maximum is 5 5V 4 1 1 2 VN 100 SMT Serial UART Interface The serial interface on the VN 100 operates with 3V TTL logic Table 3 Serial I O Specifications Specification Min Typical ER Input
48. emory The module can always be reset to the factory settings by issuing the Restore Factory Settings command Section 0 or by pulling pin 15 high during reset Table 18 Example Write Settings Command Example Command Message UART Command UART Response SPI Command 8 bytes 03 00 00 00 00 00 00 00 shown as hex SPI Response 8 bytes 00 03 00 00 00 00 00 00 shown as hex 6 4 4 Restore Factory Settings Command This command will restore the VN 100 module s factory default settings see Section 8 and reset the module There are no parameters for this command The module will respond to this command before restoring the factory settings Table 19 Example Restore Factory Settings Command Example Command Message UART Command UART Response SPI Command 8 bytes SPI Response 8 bytes 6 4 5 Tare Command The Tare command will have the module zero out its current orientation The effect of this command in 2D magnetic mode will be to set only the yaw angle to zero In 3D heading mode the VN 100 will set the yaw pitch and roll angles to zero In 3D heading mode the VN 100 will also now measure yaw pitch and roll relative to the alignment of the respective Z Y and X axis in 3D space when the tare command was received For more information on how to change the magnetic mode see Section 7 35 MP www vectornav com 35 102 VN 100 User Manual UMO01 Table 20 Example Tare Command Example Command Message
49. ent have occurred at some point between the times the chip was calibrated at the factory and when it is used in the field X COO C01 C02 Mx BO Ye C10 C11 C12 MY B1 Z C20 C21 C22 MZ B2 The variables MX MY MZ are components of the measured magnetic field The X Y Z variables are the new magnetic field measurements outputted after compensation for hard soft iron effects All twelve numbers are represented by single precision floating points KA www vectornav com 65 102 VN 100 User Manual UMO01 7 25 Filter Active Tuning Parameters Filter Active Tuning Parameters Register ID 24 Firmware v0 1 and up Access Read Write Legacy active tuning parameters Supported for reverse compatibility For new designs it is Comment recommended to use the adaptive tuning feature in VPE Magnetometer Basic Tuning Register Section 0 and the VPE Accelerometer Basic Tuning Register Section 7 39 Size Bytes 16 Example Serial Read Register Response Byte Number Offset Name Format Unit Description 0 MagGain F4 Magnetic Disturbance Gain 0 to 10 4 AccGain Fa Acceleration Disturbance Gain 0 to 10 8 MagMemory F4 Magnetic Disturbance Memory 0 to 1 12 AccMemory F4 Acceleration Disturbance Memory 0 to 1 SVNRRG 24 0 0 0 99 0 9 4C MP www vectornav com 66 102 VN 100 User Manual UMO001 7 26 Accelerometer Compensation Accelerometer Compensatio
50. eter to be compensated for hard soft iron effects Size Bytes 48 Example Serial Read Register SVNRRG 23 1 0 0 0 1 0 0 0 1 0 0 0 73 Response Byte Number Offset Name Format Unit Description LC a Access Read Write 4 cfoij ra TN 12 cio ea 16 cay aT 20_ cit2 2 ee Ss SESS a 2g ciza 32 c2 rae 36_ poo ss ee ae ea ae i a This register contains twelve values representing the hard and soft iron compensation parameters The magnetic measurements are compensated for both hard and soft iron using the following model Under normal circumstances this register can be left in its factory default state In the event that there are disturbances in the magnetic field due to hard or soft iron effects then these registers allow for further compensation These registers can also be used to compensate for significant changes to the magnetometer bias gain and axis alignment during installation Note that this magnetometer compensation is separate from the compensation that occurs during the calibration process at the factory Setting this register to the default state of an identity matrix and zero offset will not eliminate the magnetometer gain bias and axis alignment that occur during factory calibration These registers only need to be changed from their default values in the event that hard soft iron compensation needs to be performed or changes in bias gain and axis alignm
51. filter cycle If this happens then the VN 100 will continue to use the previously set external magnetometer measurement until it receives a new update If you wish to have the attitude filter only use the magnetometer data to update the attitude filter when the magnetometer measurement updates then set the ExtMagMode field to 2 In this state the magnetometer will be tuned out during the time steps that it isn t updated AA www vectornav com 22 102 VN 100 User Manual UMO001 4 Specifications 4 1 Pin out and Electrical Specifications 4 1 1 VN 100 Surface Mount Sensor SMT Figure 7 Pin assignments top down view C 15 SYNC_IN_2 C 9 SYNC_OUT 14 RESV A C 13 RX1 12 TX1 2 C 11 ENABLE fo C 10 VIN 19 SPI_MISO 20 REPRGM 22 SYNC_IN 23 SPI_CS iV fy N N ine pe No ine ine wo 7 GB oN PS Ye 2 y d3 D 3 D O on o oO B Z B g lt lt lt lt U V9 KAA www vectornav com 23 102 VN 100 User Manual Pin 1 12 13 14 15 16 17 18 Pin Name GND GND GND GND TX2 RX2 TARE RESTORE NC SYNC_OUT VIN ENABLE TX1 RX1 RESV SYNC_IN_2 SPI_SCK SPI_MOSI GND UMO001 Table 2 VN 100 SMT Pin Assignments Description Normally used to zero tare the attitude To tare pulse high for at least 1 us During power on or device reset holdin g this pin high will cause the module to restore its default factory settings Because of this the pin cannot be us
52. gnetic disturbance is present KnownAccDisturbancePresent 12 1bit Aknown acceleration disturbance is present RESERVED Tat Bits PO Table 51 AttitudeQuality Field Name Format Description VEIN Description o f eeuen www vectornav com 88 102 VN 100 User Manual UMO001 7 43 Filter Startup Gyro Bias RegisterID 43 Firmware v1 1 and up Access Read Write Comment The filter gyro bias estimate used at startup Size Bytes 12 Example Serial Read Register VNRRG 43 00 000000 00 000000 00 000000 5D Response Byte Number Offset Name Format Unit Description 0 X Axis Gyro Bias Estimate Filter initial gyro bias estimate X Axis 4 Y Axis Gyro Bias Estimate Filter initial gyro bias estimate Y Axis 8 Z Axis Gyro Bias Estimate Filter initial gyro bias estimate Z Axis MP www vectornav com 89 102 VN 100 User Manual UMO001 7 44 Magnetometer Basic Calibration Control Filter Tuning Status Register ID 44 Firmware v1 1 and up Access Read Write Comment Controls the magnetometer real time calibration algorithm Size Bytes 4 Example Serial Read Register SVNRRG 44 1 2 5 69 Response Byte Number Offset Name Format Unit Description Controls the mode of operation for the onboard real time 0 HSIMode U1 magnetometer hard soft iron compensation algorithm Controls the type of measurements that are provided as outputs from 1 HSlOutput U1 the
53. gnetic field measurements Typically when the device is used as an IMU the attitude information isn t required The VN 100 will always compute the attitude solution onboard regardless of whether it is being used or not The VN 100 offers a SyncOut line that can be software configured to trigger either when the IMU or the attitude measurements are available The device defaults to trigger when the attitude information is available To reduce the measurement latency when the device is solely used as an IMU it is recommended that the SyncOut line is switched to trigger when new IMU measurements are available The VN 100 provides two different angular rate measurements The un compensated rate measurements available in Register 252 come straight from the calibrated gyro and are not altered by the onboard running Kalman filter The compensated rate measurements available in Register 20 are corrected for the gyro bias drift by the onboard Kalman filter When the Kalman filter is properly tuned the compensated rates are drift free Normally however for an IMU uncompensated angular rates are preferred since gyro bias estimation is usually handled by a higher level filter Setting up the VN 100 as an IMU To use the VN 100 as an IMU from the factory default state performs the following steps 1 Set the SyncOut to trigger when the IMU data is available For more information on this register see Section 7 33 Interface Write Register Set SyncOut to I
54. h this register the user can specify which data register will be automatically outputted when it gets updated with a new reading Table 28 lists which registers can be set to asynchronously output the value to specify which register to output and the header of the asynchronous data packet Asynchronous data output can be disabled by setting this register to zero The asynchronous data output will be sent out automatically at a frequency specified by the Async Data Output Frequency Register Section 7 8 SVNRRG 06 0 69 MP www vectornav com 47 102 VN 100 User Manual UMO001 Table 28 Asynchronous Solution Output Settings Setting Asynchronous Solution Output Type Header Formatting Section 0 Asynchronous output turned off N A 3 4 5 o V Magnetic Acceleration and Angular VNQMR 10 11 12 Magnetic Acceleration and Angular Rate VNMAR Measurements Yaw Pitch Roll Magnetic Acceleration and Angular VNYMR 7 28 Rate Measurements Yaw Pitch Roll amp Calibrated Measurements VNYCM Yaw Pitch Roll Body True Acceleration and Angular VNYBA Rates Yaw Pitch Roll Inertial True Acceleration and VNYIA 7 49 Angular Rates Yaw Pitch Roll Inertial Magnetic Acceleration and VNICM 7 50 Angular Rate Measurements 252 253 254 255 KAA www vectornav com 48 102 VN 100 User Manual UMO001 7 8 Async Data Output Frequency Register Asynchronous Data Output Frequency Register ID 7 Firmware
55. hat changes in bias gain and axis alignment have occurred at some point between the times the chip was calibrated at the factory and when it is used in the field X COO C01 C02 AX BO Ye C10 C11 C12 AY B1 Z C20 C21 C221 AZ B2 The variables AX AY AZ are components of the measured acceleration The X Y Z variables are the new acceleration measurements outputted after compensation for changes during sensor mounting All twelve numbers are represented by single precision floating points KA www vectornav com 67 102 VN 100 User Manual UMO001 7 21 Reference Frame Rotation Reference Frame Rotation Register ID 26 Firmware v0 1 and up Access Read Write Allows the measurements of the VN 100 to be rotated into a different reference Comment ame Size Bytes 36 Example Serial Read Register Response Byte Number SVNRRG 26 1 0 0 0 1 0 0 0 1 6A Offset Name Format Unit Description o coo d m Sik SSS SSeS kh ee ee 12 cio r 16 cay rT 20_ cit2 2 SSS SSeS Ss 2g _ ciaa TC 32 oma eC This register contains a transformation matrix that allows for the transformation of measured acceleration magnetic and angular rates from the body frame of the VN 100 to any other arbitrary frame of reference The use of this register allows for the sensor to be placed in any arbitrary orientation with respect to the user s desired body coordinate frame This register
56. heading estimates While in Indoor Heading mode the VPE inspects the magnetic measurements over long periods of time performing several different tests on each measurement to quantify the likelihood that the measured field is free of the influence of any position dependent local magnetic fields which would distort the magnetic field direction Using this probability the VPE then estimates the most likely direction of the Earth s magnetic field and uses this information to correct for the heading error while the device is in motion NP www vectornav com 14 102 VN 100 User Manual UMO001 Indoor Heading Mode Advantages e Capable of handling short term and long term magnetic interference e Can handle significant errors in the hard soft iron while still maintaining a stable heading and gyro bias estimate e Capable of maintaining an accurate absolute heading over extended periods of time Indoor Heading Mode Disadvantages e Measurement repeatability may be slightly worse than Relative Mode during periods when the VPE corrects for known errors in absolute heading 2 12 Overview of Heading Modes A summary of the different types of disturbances handled by each magnetic mode is summarized in the table below Table 1 Types of Disturbances handled by each Magnetic Mode Capabilities Absolute Heading Relative Heading Indoor Mode Handle high frequency magnetic disturbances 6 q y g Yes Yes Yes greater than 1Hz Handle constant distur
57. hown as hex SPI Response 8 bytes 00 08 01 00 00 00 00 00 shown as hex AA www vectornav com 36 102 VN 100 User Manual UMO001 6 4 8 Known Acceleration Disturbance Command This command is used to notify the VN 100 that an acceleration disturbance is present When the VN 100 receives this command it will tune out the accelerometer A single parameter is provided to tell the VN 100 whether the disturbance is present or not 0 No Disturbance is present 1 Disturbance is present Table 23 Example Acceleration Disturbance Command Example Command Message UART Command B UART Response SPI Command 8 bytes 09 01 00 00 00 00 00 00 shown as hex SPI Response 8 bytes 00 09 01 00 00 00 00 00 shown as hex 6 4 9 Set Gyro Bias Command This command is used to save the current gyro bias estimate to memory for use at startup Make sure that the device remains perfectly still when you send this command If this command is sent along with a write settings command after startup the VPE will use the saved gyro bias as opposed to assuming that it is zero This will reduce the time required to output a stable attitude and angular rate estimate Table 24 Example Gyro Bias Command Example Command Message 6 5 System Error Codes In the event of an error the chip will output SVNERR followed by an error code The possible error codes are listed in the table below with a description of the error Table 25
58. ial X axis Calibrated magnetometer measurement in the inertial Y axis Calibrated magnetometer measurement in the inertial Z axis Calibrated accelerometer measurement in the inertial X axis Calibrated accelerometer measurement in the inertial Y axis Calibrated accelerometer measurement in the inertial Z axis Calibrated un compensated angular rate in the body X axis Calibrated un compensated angular rate in the body Y axis Calibrated un compensated angular rate in the body Z axis Q oO ma 9 D n mS Q oO oq S D BK 3 Q oO a Is oa Sal mS 12 Inertial_MagxX 16 Inertial_MagY 20 Inertial_ MagZ 24 Inertial_AccelX 28 Inertial_AccelY Inertial_AccelZ GyroX GyroY GyroZ mui ES 3 Sea wn NI D 3 wn F4 4 F4 am fod Q n fod Q Feen v AA www vectornav com 96 102 VN 100 User Manual UMO01 7 51 Raw Voltage Measurements Raw Voltage Measurements Register ID 251 Firmware v0 1 and up Access Read Only Comment Provides the raw voltage measurements from each of the onboard sensors 40 Size Bytes Example Serial Read Register SVNRRG 251 1 349903 1 487589 1 681984 1 434724 1 450579 1 591674 1 284848 1 276317 1 294371 1 334271 42 Response Byte Number Offset Name Format 0 MagxX 4 MagyY Unit Description volt Raw voltage measured on X axis magnetometer Raw voltage measured on Y axis magne
59. ide enough error detection a full 16 bit CRC is available The VN 100 uses the CRC16 CCITT algorithm The resultant CRC is a 16 bit number and is represented in the command as four hexadecimal characters The C function snippet below calculates the correct CRC KAA www vectornav com 29 102 VN 100 User Manual unsigned short calculateChecksum char command int length UM001 unsigned int i unsigned short cre 0 i lt length i crc unsigned for i 0 char cre gt gt 8 cre lt lt 8 Cre cre Cre Cre command i u8 cre amp Oxff cre lt lt 8 lt lt 4 crce amp Oxff lt lt 4 return crc 5 3 The SPI interface uses a lightweight binary message format The start of a command is signaled by pulling the VN 100 module s chip select pin pin 23 low Both the chip select line and clock are active low The first byte transmitted to the module should be the command ID and then a variable number of bytes will follow dependent on the type of command specified A communication transaction can be cancelled at any time by releasing the chip select pin Pulling the pin low again will start a new communication transaction All binary data is sent to and from the chip with most significant bit MSB first in little endian byte order with pad bytes inserted where required to ensure 16 bit values are aligned to two byte boundaries and 32 bit values are aligned to 4 byte boundaries F
60. ion Calculated Magnetometer Calibration Register ID 47 Firmware v1 1 and up Access Read Only Comment Calculated magnetometer calibration values Size Bytes 48 Example Serial Read Register SVNRRG 46 1 0 0 0 1 0 0 0 1 0 0 0 70 Response Byte Number Offset Name Format Unit Description eo as a AO e T es T O a TE TE TA ie ee Zeya e271 2 ee ee ee SE SSE SEs ao ein ra a fea Fa _ This register contains twelve values representing the calculated hard and soft iron compensation parameters The magnetic measurements are compensated for both hard and soft iron using the following model X C00 C01 C02 MX BO Ye C10 C11 C12 MY B1 Z C20 C21 C22 MZ B2 The variables MX MY MZ are components of the measured magnetic field The X Y Z variables are the new magnetic field measurements outputted after compensation for hard soft iron effects KAA www vectornav com 92 102 VN 100 User Manual UMO001 7 47 Indoor Heading Mode Control Register ID 48 Firmware v1 1 and up Access Read Write Comment Provides control over various features relating to the indoor heading mode Size Bytes 8 Example Serial Read VNRRG 47 1 0 71 Register Response Sara Byte Number Offset Name Format Unit Description 0 Reena EETAT F4 The maximum allowable error in the estimated heading rate Controls how 4 quickly the VPE will recover a known heading er
61. ion NONE 0 o SYNCIN_COUNT Syncin Counter SYNCIN_TIME Syncin Time SYNCOUT_COUNT SyncOut Counter 7 31 4 SPlIStatus The AsyncStatus field provides a means of tracking real time status information pertaining to the overall state of the sensor measurements and onboard filtering algorithm This information is very useful in situations where action must be taken when certain crucial events happen such as the detection of gyro saturation or magnetic interference Table 34 SPIStatus Value Description o oF ES ESS a KA www vectornav com 73 102 VN 100 User Manual UMO001 7 31 5 SerialChecksum This field controls the type of checksum used for the serial communications Normally the VN 100 uses an 8 bit checksum identical to the type used for normal GPS NMEA packets This form of checksum however offers only a limited means of error checking As an alternative a full 16 bit CRC CRC16 CCITT with polynomial 0x07 is also offered The 2 byte CRC value is printed using 4 hexadecimal digits Table 35 SerialChecksum Value Description OFF Si era 7 31 6 SPIiChecksum This field controls the type of checksum used for the SPI communications The checksum is appended to the end of the binary data packet The 16 bit CRC is identical to the one described above for the SerialChecksum Table 36 SPIChecksum Value Description OFF m 7 31 7 ErrorMode This field controls the type of action taken by the VN
62. is parameter can be adjusted from 0 to 10 e Zero places no confidence or infinite uncertainty in the sensor thus eliminating its effect on the attitude solution KAA www vectornav com 15 102 VN 100 User Manual UMO001 e Ten places full confidence minimal uncertainty in the sensor and assume that its measurements are always 100 correct 2 15 Adaptive Tuning Gain The adaptive tuning stage of the VPE monitors both the magnetic and acceleration measurements over an extended period of time to estimate the time varying level of uncertainty in the measurement The adaptive tuning gain directly scales either up or down this calculated uncertainty e This parameter can be adjusted from 0 to 10 e The minimum value of zero turns off all adaptive tuning e The maximum value of 10 applies several times the estimated level of uncertainty 2 16 Adaptive Filtering Gain The adaptive filtering stage of the VPE monitors both the magnetic and acceleration measurements to determine if large amplitude high frequency disturbances are present If so then a variable level of filtering is applied to the inputs in order to reduce the amplitude of the disturbance down to acceptable levels prior to inputting the measurement into the attitude filter The advantage of the adaptive filtering is that it can improve accuracy and eliminate jitter in the output attitude when large amplitude AC disturbances are present The disadvantage to filtering is that it will inhe
63. ister ID 46 Firmware v1 1 and up Access Read Only Comment Status of the magnetometer real time calibration algorithm Size Bytes 28 Example Serial Read Register SVNRRG 45 2 1 0 00566713 0 424594 0 587841 1 80009 0 0 1 0 0 0 0 0 4D Response Byte Number Offset Name Format Unit Description o LastBin U1 Thebin for the most recently collected magnetic measurement 1 NumMeas u2 The number of measurements currently used in the solution 4 AvgResidual F4 The average residual error for magnetic measurements 8 LastMeasX La The most recently collected magnetic measurement X axis 12 LastMeasY F4 The most recently collected magnetic measurement Y axis 16 LastMeasZ F4 The most recently collected magnetic measurement Z axis 20 Binsfo U1 Thenumber of measurements collected in Bin 1 21 SB 41s The number of measurements collected in Bin 2 22 Bins 2 _ ua __ The number of measurements collected in Bin 3 23 Bins 3 u The number of measurements collected in Bin 4 24 Bins 4 U1 The number of measurements collected in Bin 5 25 Bins i5 u The number of measurements collected in Bin 6 26 Binse U1 Thenumber of measurements collected in Bin 7 27 Bins 7 _ ua The number of measurements collected in Bin 8 AA www vectornav com 91 102 VN 100 User Manual UMO01 7 46 Calculated Magnetometer Calibrat
64. itude quaternion 8 P22 F4 Variance for Z axis vector component of attitude quaternion 12 Ln ll aE Variance for X axis gyro bias estimate 16 Pi44 Fa Variance for Y axis gyro bias estimate 20 P 5 5 F4 Variance for Z axis gyro bias estimate SVNRRG 254 4 462022E 06 4 669347E 06 1 912999E 04 4 470797E 07 4 477159E 07 1 033085E 06 46 AA www vectornav com 100 102 VN 100 User Manual UMO001 8 System Registers Default Factory State The following table details the VN 100 module s settings as it is delivered from the factory These settings may be restored by issuing a Restore Factory Settings command Section 0 or by using the Restore Factory Settings signal pins Table 54 Factory Default Register Values Settings Name Default Factory Value Serial Baud Rate 115200 Async Data Output Frequency Async Data Output Type YMR Yaw Pitch Roll Magnetic Acceleration amp Angular Rates i 1 0e 0 0 0e 0 1 8e 0 Magnetic and Gravity Reference Vectors 0 0e 0 0 0e 0 9 793746e 0 1 0e 10 1 0e 6 1 0e 6 1 0e 6 Filter Measurement Variance Parameters 1 0e 2 1 0e 2 1 0e 2 1 0e 2 1 0e 2 1 0e 2 a er elton Goh enSaksin 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 Parameters 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 Accelerometer Gain FO KAA www vectornav com 101 102 VN 100 User Manual
65. lowed level of filtering for Z Axis 24 Controls the rate the filtering level is allowed to change 28 Width of disturbance tuning window 32 Maxtuning F4 Maximumallowed estimated measurement variance AA www vectornav com 84 102 VN 100 User Manual UMo001 7 39 VPE Accelerometer Basic Tuning Byte Offset 0 o0 12 16 20 24 28 32 VPE Accelerometer Basic Tuning Register ID 38 Firmware v1 1 and up Access Read Write Comment Provides basic control of the adaptive filtering and tuning for the accelerometer Size Bytes 36 Example Serial Read Register Response Number Name Format Min Max BaseTuningX 0 10 BaseTuningY 0 10 BaseTuningZ 0 10 SVNRRG 38 5 5 5 3 3 3 4 4 4 66 Description Base Accelerometer Tuning X Axis 0 10 This sets the level of confidence placed in the accelerometer X axis when no disturbances are present A larger number provides better pitch roll heading accuracy but with more sensitivity to acceleration interference Base Accelerometer Tuning Y Axis 0 10 This sets the level of confidence placed in the accelerometer Y axis when no disturbances are present A larger number provides better pitch roll accuracy but with more sensitivity to acceleration interference Base Accelerometer Tuning Z Axis 0 10 This sets the level of confidence placed in the accelerometer Z axis when no disturbances are present A larger number provide
66. m 4 102 VN 100 User Manual UMO001 7 30 7 31 7 31 1 7 31 2 7 31 3 7 31 4 7 31 5 7 31 6 7 31 7 7 31 8 7 32 7 33 7 33 1 7 33 2 7 33 3 7 33 4 7 33 5 7 33 6 7 33 7 7 34 7 35 7 36 7 37 7 38 7 39 7 40 7 41 7 42 7 43 7 44 7 45 AR Yaw Pitch Roll amp Calibrated Measurements cccecccceseseeeeeeeeeeeseees 71 Communication Protocol CONtKOl cccsssssecceeeceeeessesenteeeeeeeeeeeeeeeeeenes 72 S rial COUNT cc eat hea nett arinaa i aaa eaaa aaea tated 72 SSN Val SEAMING toss cite i stececvcs iiear isi ie na Doe Ue ew te ae EENE TSESAREN ARE e 73 SPICOUME sx ainina aeron etrean e ode c eveienctucedeudsGbevanatucedduetdveiencticedendtseensnetie 73 SPIStA US tga cings rsreadres ts ven oscc cin inapanten nese chants o arrra rretan rnnr rr ernari 73 Belial CMG C KS OR rrisaceiductschdacaatavotesniebontdevedsndatlend Jncdenddstatnwdbenddenn ntdsnnstiudactedvbeunnreiesdeiad 74 SPICMICK SUM ssts scenes cs acne cave nn deuatcuerancsedineededutetesied st LEERT aE EE EIEE AO ENARA SEE 74 BEM OM VIO ccs cass asaziats aban sadtnaczeahiatdanauaadencadnau auaseaensaaiudsnaanietigdaalaaauemncdamieaaman 74 Example Async MESSag 6S ssssscccecceecssssssaeeececeescsesseasseseceeseesseeuseaeeeeseseeeseeaaeeas 74 Communication Protocol Stat US xccisceess sisssaednddicenessessalaceehs Neen datieseasaees 76 Synchronization Control sssassiiodcmusseranriadsantivetaonadiioemiieionsenatixinaanins 77 SyntlIAMOd E urriei niriiion
67. mpensated angular rate in z axis m Tm By A www vectornav com 56 102 VN 100 User Manual UMO001 7 16 Quaternion Magnetic Acceleration and Angular Rates Quaternion Magnetic Acceleration and Angular Rates Register ID 15 Firmware v0 1 and up Access Read Only Comment Attitude solution magnetic acceleration and compensated angular rates Size Bytes 52 Example Serial Read Register SVNRRG 15 0 017057 0 000767 0 056534 0 998255 1 0670 0 2568 3 0696 Response 00 019 00 320 09 802 0 002801 0 001186 0 001582 65 Byte Number Offset Name Format Unit Description Quat 0 F4 Calculated attitude as quaternion gt 4 Quatj1 F4 Calculated attitude as quaternion 8 Quat 2 F4 Calculated attitude as quaternion 12 Quat 3 F4 Calculated attitude as quaternion Scalar component 16 Max Fa Calibrated magnetometer measurement in x axis 20 May o m Calibrated magnetometer measurement in y axis n gt Maz Fa Calibrated magnetometer measurement in z axis Calibrated accelerometer measurement in x axis Calibrated accelerometer measurement in y axis Calibrated accelerometer measurement in z axis Gyrox F4 rad s Calibrated amp filter bias compensated angular rate in x axis GyroYy F4 rad s Calibrated amp filter bias compensated angular rate in y axis Gyro
68. n Register ID 25 Firmware v0 1 and up Access Read Write Allows the accelerometer to be further compensated for scale factor misalignment and bias errors Size Bytes 48 Example Serial Read Register Response Byte Offset Name 0 C 0 0 Comment SVNRRG 25 1 0 0 0 1 0 0 0 1 0 0 0 75 Number Format Unit Description m C SES TE ra TN 12 cio ea 16 cay aT 20_ cit2 2 ee Ss SESS a 2g ciza 32 c2 rae 36_ poo ss ee ae ea A m Sea This register contains twelve values representing the accelerometer compensation parameters The accelerometer measurements are compensated for changes in bias gain and axis alignment that can occur during the installation of the chip on the customer s board using the following model Under normal circumstances this register can be left in its factory default state In the event that there are significant changes to the accelerometer bias gain and axis alignment during installation then these registers allow for further compensation Note that this accelerometer compensation is separate from the compensation that occurs during the calibration process at the factory Setting this register to the default state of an identity matrix and zero offset will not eliminate the accelerometer gain bias and axis alignment that occur during factory calibration These registers only need to be changed from their default values in the event t
69. nd to read register 8 The available registers which can be read or written to are listed in Table 26 At the same time zeros are received by the master assuming no previous SPI command was sent to the chip since reboot On the second transaction the master sends the command to read register 13 At the same time the response from the previously requested register 8 is received by the master on the MISO line It consists of four 32 bit words The first byte of the first word will always be zero The second byte of the first word is the type of command that this transaction is in response to In this case it is a 0x01 which means that on the previous transaction a read register command was issued The third byte of the first word is the register that was requested on the previous transaction In this case it shows to be 0x08 which is the yaw pitch roll register The fourth byte of the first word is the error code for the previous transaction Possible KA www vectornav com 31 102 VN 100 User Manual UMO001 error codes are listed in Table 25 The remaining three 4 byte words are the yaw pitch and roll respectively given as single precision floating point numbers The floating point numbers are consistent with the IEEE 754 standard On the third SPI transaction 16 bytes are clocked on the SCK line during which zeros are sent by the master since no further data is required from the sensor These 16 bytes are clocked out the SPI for the sole purpose of
70. nificant errors in the hard soft iron while still maintaining a stable heading and gyro bias estimate Relative Heading Mode Disadvantages e Unable to maintain heading estimate relative to true North in environments with frequent long term magnetic field disturbances 2 11 Indoor Heading Mode The Indoor Heading mode was designed to meet the needs of applications that require the enhanced magnetic disturbance rejection capability of the Relative Heading mode yet desire to maintain an absolute heading reference over long periods of time The Indoor Heading mode extends upon the capabilities of the Relative Heading mode by making certain assumptions as to the origin of the measured magnetic fields consistent with typical indoor environments In any environment the measured magnetic field in 3D space is actually the combination of the Earth s magnetic field plus the contribution of other local magnetic fields created by nearby objects containing ferromagnetic materials For indoor environments this becomes problematic due to the potential close proximity to objects such as metal desk chairs speakers rebar in the concrete floor and other items which either distort or produce their own magnetic field The strength of these local magnetic fields are position dependent and if the strength is on the same order of magnitude as that of the Earth s magnetic field directly trusting the magnetic measurements to determine heading can lead to inaccurate
71. nized with external devices 44 31 Firmware v1 1 and up Access SVNRRG 31 25 0 6 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 70 Number Format Unit Description Number of successfully parsed serial messages received Number of successfully parsed SPI messages received Maximum percent usage of serial incoming buffer 9 MaxUsageSerialTXBuffer 10 MaxUsageSPIRXBuffer 11 MaxUsageSPITXBuffer SysErrors ur U2iie ay N S Maximum percent usage of serial outgoing buffer Maximum percent usage of SPI incoming buffer Maximum percent usage of SPI outgoing buffer Total number of each type of system error received www vectornav com 76 102 VN 100 User Manual UMO001 7 33 Synchronization Control Synchronization Control Register ID 32 Firmware v1 1 and up Access Read Write Contains parameters which allow the timing of the VN 100 to be synchronized with external devices 20 Comment Size Bytes Example Serial Read Register Response Byte Number Offset Name Format Unit Description SVNRRG 32 0 0 0 0 3 0 0 500000 0 58 0 SyncinMode u Input signal synchronization mode al SyncinEdge ui Input signal synchronization edge selection 2 SyncinSkipFactor U2 Input signal trigger skip factor 4 RESERVED u4 Reserved for future use Defaults to 0 8 SyncOutMode u Output synchronization signal m
72. nse Byte Number SVNRRG 21 1 0 1 8 0 0 9 79375 53 Offset Name Format Unit Description 0 X Axis Magnetic Reference 4 Y Axis Magnetic Reference 8 Z Axis Magnetic Reference 12 X Axis Gravity Reference 16 Y Axis Gravity Reference 20 Z Axis Gravity Reference MP www vectornav com 63 102 VN 100 User Manual UMO01 7 23 Filter Measurements Variance Parameters Filter Measurement Variance Parameters Register ID 22 Firmware v0 1 and up Access Read Write Comment Attitude Kalman Filter measurement uncertainty variances Size Bytes 40 Example Serial Read Register SVNRRG 22 5E 08 3E 06 3E 06 3E 06 0 5 0 5 0 5 0 001 0 001 0 001 7F Response Byte Number Offset Name Format Unit Description 2 rad 4 ARWX F4 Variance X Axis Angular Rate rad 8 ARWY F4 Variance Y Axis Angular Rate rad 3 12 ARWZ F4 Variance Z Axis Angular Rate 16 VMAGX Variance X Axis Magnetic 20 VMAGY Variance Y Axis Magnetic 24 VMAGZ Variance Z Axis Magnetic m 2 23 VACCX F4 Variance X Axis Acceleration m 2 32 VACCY F4 s Variance Y Axis Acceleration m 2 36 VACCZ F4 Variance Z Axis Acceleration MP www vectornav com 64 102 VN 100 User Manual UMO001 7 24 Magnetic Hard Soft Iron Compensation Parameters Magnetic Hard Soft Iron Compensation Parameters Register ID 23 Firmware v0 1 and up Comment Allows the magnetom
73. ode 9 SyncOutPolarity ui Output synchronization signal polarity 10 SyncOutSkipFactor U2 Output synchronization signal skip factor 12 Output synchronization signal pulse width 16 Reserved for future use Defaults to 0 7 33 1 SynclnMode The SyncinMode register controls the behavior of the Syncin event If the mode is set to COUNT then the internal clock will be used to control the ADC timing If SynclnMode is set to ASYNC then the ADC loop will run on a Syncin event The relationship between the Syncin event and a Syncin trigger is defined by the SynclnEdge and SyncInSkipFactor parameters It is very important to note that the VN 100 must always operate at an internal rate of 200Hz If the Syncin event is used to control the ADC sampling then the Syncin event must be kept always at 200Hz If set to ASYNC then the VN 100 will output asynchronous serial messages upon each trigger event Table 38 Syncin Mode Mode Pin Value Description COUNT2 SYNC_IN 2 Count number of trigger events on SYNC_IN_2 pin 15 ADC2 SYNC_IN_2 Start ADC sampling on trigger of SYNC_IN_2 pin 15 ASYNC2 SYNC_IN_2 Output asynchronous message on trigger of SYNC_IN_2 pin 15 Start ADC sampling on trigger of SYNC_IN pin 22 SYNC_IN Output asynchronous message on trigger of SYNC_IN pin 22 ASYNC SYNC_IN Po AA www vectornav com 77 102 VN 100 User Manual UMO001 7 33 2 SyncinEdge The SynclnEdge register controls the typ
74. of the adaptive filtering and tuning for the gyro Size Bytes 36 Example Serial Read Register Response Byte Number Offset Name Format Min Max Description 0 VAngularWalkx 1e 15 1e 2 Variance Angular Walk X Axis 4 VAngularWalkY le 15 1e 2 Variance Angular Walk Y Axis 8 VAngularWalkZ 1e 15 1e 2 Variance Angular Walk Z Axis Base Gyro Tuning X Axis 0 10 E ng This sets the level of confidence placed in the gyro X Axis Base Gyro Tuning Y Axis 0 10 1 CARNE om f oom This sets the level of confidence placed in the gyro Y Axis Base Gyro Tuning Z Axis 0 10 PEE ra nae This sets the level of confidence placed in the gyro Z Axis 24 AdaptiveTuningX 0 10 Level of adaptive tuning for X Axis 28 AdaptiveTuningY 0 10 Level of adaptive tuning for Y Axis 32 AdaptiveTuningZ 0 10 Level of adaptive tuning for Z Axis SVNRRG 40 5 5 5 3 3 3 4 4 4 69 AA www vectornav com 87 102 VN 100 User Manual UMOO01 7 42 Filter Status Filter Status Register ID 42 Firmware v1 1 and up Access Read Only Comment Provides overall status of the onboard Kalman Filter Size Bytes 28 Example Serial Read Register Response Byte Offset SVNRRG 42 0004 0 188461 0 0283489 0 0277957 0 120018 0 0112458 0 00154995 6E Number Format Unit fee NEME Description Solution status bitfield 0 SolutionStatus See description below On serial interfac
75. olution For some applications it is desirable to use a separate accelerometer or magnetometer with the VN 100 For example on Unmanned Aerial Vehicles UAVs the IMU is typically located close to the center of gravity while the magnetometer is located further away from the electronics such as out on the end of the wing This can be accomplished by setting the ExtWagMode field in the Filter Control Register Section 7 35 Set the VN 100 to use an External Magnetometer Send the following command to the VN 100 to instruct it to use an external magnetometer Interface Write Register Use External Magnetometer SVNWRG 34 2 0 1 0 72 SPI 02 22 00 00 02 00 01 00 Set the VN 100 to use an External Accelerometer Send the following command to the VN 100 to instruct it to use an external accelerometer Interface Write Register Use External Magnetometer SVNWRG 34 0 2 1 0 72 SPI 02 22 00 00 00 02 01 00 In the Filter Control Register Section 7 35 the ExtMagMode and the ExtAccMode fields allow you to set which type of magnetometer and accelerometer respectfully are used by the onboard attitude filter How to update the External Magnetometer Measurements In order to update the external magnetometer measurements you will need to write to the Calibrated IMU Measurements Register Section 7 52 This register normally is read only however when either the ExtMagMode or the ExtAccMode is set to use an external sensor then writing to this regi
76. omain aes anaes 37 7 System REBISCEIS vi sscccdinsvesccssvednscertiesesatscvcartvereaweriasaunetseneaneeeseneens 38 KA www vectornav com 3 102 VN 100 User Manual UMO001 TA User Tag Register erneer naaa nean E AKARE OE TEATELE 41 7 2 Model Number Register wisisssscascsssanssvavsancstassanstacasncssaaratarassrnsnteasevonriasiasvass 42 7 3 Hardware Revision R giSter ccccccccccceccceccceccceecceeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 43 7 4 Serial Number Register nuennnuensrenererererrrerrrerrrerrrerrrerrrerrrerrrerrrerrrerreere 44 7 5 Firmware Version Register cccccccccceccceccceecceeceeccceeceeeceeeceeeeeeeeeseeeeeeeeeeees 45 7 6 Serial Baud Rate REG Str saiassscssespianeasersartstassaseicatoersedsinassenanietasvaysiouseads 46 7 7 Async Data Output Type RegiSter ccccccccccccssssesseceeccceesseaeeaeseeeeeeeeess 47 7 8 Async Data Output Frequency ReQiSter ccccssssseseececcceecaeeeesseseeeeeeeeees 49 7 9 Attitude Yaw Pitch Roll Format seessssesessssseressesessssrrrerrerssessrrrrrrrreresssse 50 7 10 Attitude Quaternion ssssssssssessssssssssrrresrrrssssrrsrerrersrresesreerrrressssesesrrrrete 51 7 11 Quaternion and Magnetic cccccccccccccceccceccceeceeecceeceeeeeeeeeeeeeeeeeeeeeeeeeees 52 7 12 Quaternion and Acceleration ccccccccccccssssssssnececeeeecesssesssneeeeeeeeeeeees 53 7 13 Quaternion and Angular Rates cccccccccccccccecccecccecceeeceeeceeeceeeeeeeeeeeeeess 54 7
77. or example the serial baud rate register with a value of 9600 0x2580 would be sent across the SPI as a 0x80 0x25 0x00 0x00 Data is requested from and written to the device using multiple SPI transactions SPI Interface Figure 10 SPI Timing Diagram NSS input SU NSS gt lt te SCK th NSS yx twW SCKH q gt I E a e Oe os ae 1 1 i i ff i i l i i t tiSCK i tasoj v SO h SO hoa tdis SO stow avon Xion SCK Input OUTPUT tsu Sl gt i4 th SI MOSI N E T INPUT MSBN BITI IN LSB IN www vectornav com 30 102 VN 100 User Manual UMO001 Figure 11 SPI Data Diagram A response for a given SPI command will be sent over the MISO line on the next SPI transaction Thus the data received by the Master on the MISO line will always be the response to the previous transaction So for example if Yaw Pitch Roll and angular rates are desired then the necessary SPI transactions would proceed as shown below SPI Transaction 1 SS SSS aaa aaa SPI Transaction 2 16 bytes as Gi 13 00 00 00 OO OO OO OO CO OO OW OW OO OO OO 00 0L 0e 00 239 GA 02 4G TD 43 97 CL CM OD 67 42 Yaw Pitch Roll 130 54 18 91 MISO shown as hex 57 90 SPI Transaction 3 16 bytes Coo O GO O O OO O o o O o oo o O O O O OO MISO COMORES 0O 00 T5 am zA 00 60 12 39 B9 CC SD J3 Rates 0 001465 0 000035 shown as hex 0 004327 During the first transaction the master sends the comma
78. pin is connected to the PPS Pulse Per Second SynclnTime U4 us line on a GPS and the AsyncStatus field in the Communication Protocol Register is set to 1 then each asynchronous measurement will be time stamped relative to the last received GPS measurement Keeps track of the number of times that the SyncOut trigger event has occurred This register can be used to index subsequent measurement outputs which is particularly useful when logging sensor data This field is writable to allow for initialization or clearing SyncOutCount U4 MP www vectornav com 80 102 VN 100 User Manual UMO001 7 35 Filter Basic Control Filter Basic Control Register ID 34 Firmware v1 1 and up Access Read Write Comment Provides control over various features relating to the onboard attitude filtering algorithm Size Bytes 16 Example Serial Read Register Response Byte Number SVNRRG 34 0 0 0 0 0 0 0 68 ay w N ee Selects whether the onboard magnetometer is used in 2D or 3D mode In Either the internal or an external magnetic sensor can be used For Selects what type of gyro is used by the onboard attitude filter Either the ExtGyroMode U1 saturation recovery mode if the rate Offset Name Format Unit Description ie 2D mode the magnetometer will only affect the heading Selects what type of magnetometer is used by the onboard attitude filter ExtMagMode U1 information see Section 3 6 Selects what type of acceleromete
79. r is used by the onboard attitude filter ExtAccMode U1 Either the internal or an external accelerometer sensor can be used For information see Section 3 6 internal or an external gyro sensor can be used For information see Section 3 6 ae Gyro angular rate saturation limit for the X Axis Filter will enter gyro GyroLimitX F4 rad s y te ey saturation recovery mode if the rate Gyro angular rate saturation limit for the Y Axis Filter will enter gyro Pao ro angular r turation limit for the Z Axis Filter will enter gyr e F4 ece Gy o ang ar rate satura o t for the s Filte enter gyro saturation recovery mode if the rate 1 N Table 42 MagMode Description Magnetometer will only affect heading Magnetometer will affect heading pitch and roll Table 43 ExtMagMode Description Use External Magnetometer Will only use when the measurement is updated For other time steps the measurement will be tuned out Table 44 ExtAccMode Description Use External Accelerometer Will only use when the measurement is updated For other time steps the measurement will be tuned out Table 45 ExtGyroMode Description Use Internal Gyroscope Use External Gyroscope Will use measurement at every new time step KAA www vectornav com 81 102 VN 100 User Manual UMO01 7 36 VPE Basic Control VPE Basic Control Register ID 35 Firmware v1 1 and up Access Read Write Comment Provides control over vario
80. r operational mode is selected in the Filter Control Register Section 7 35 3 3 Synchronizing the VN 100 with other devices 3 4 Synchronizing Multiple VN 100 s The synchronization feature can be used to synchronize multiple VN 100 sensors together such that all sensors sample at the same time To do this select one sensor to be the master The remaining sensors in the network will be considered slaves Connect the SyncOut line of the master to the Syncin lines of each of the slaves Figure 3 Synchronizing Multiple VN 100 s AA www vectornav com 19 102 VN 100 User Manual UMO001 Using the Synchronization Control Register Section 7 33 the master unit needs to be set to output a pulse on the SyncOut pin when the ADC sampling begins To do this send the following command to the master device Interface Write Register Set Master SyncOut SVNWRG 32 0 0 0 0 1 0 0 500000 0 5F SPI 02 20 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 07 A1 20 00 00 00 00 On each slave unit the Syncin line must be configured to trigger on the ADC sampling To do this send the following command to the slave devices Interface Write Register Set Slave Syncin SVNWRG 32 1 0 0 0 3 0 0 500000 0 5C SPI 02 20 00 00 01 00 00 00 00 00 00 00 03 00 00 00 00 07 A1 20 00 00 00 00 3 5 Running the VN 100 off an external clock It is also possible to use an external clock to drive the ADC sampling and filter loop of the VN 100 Normally the VN 100 uses it
81. reading the response from the previous read register 13 command The response consists of 4 32 bit words starting with the zero byte the requested command byte register ID error code and three single precision floating point numbers If only one register is required on a regular basis then this can be accomplished by sending the same command twice to the VN 100 The response received on the second transaction will contain the most up to date values for the desired register SPI Transaction 1 SCK 16 bytes E 0L 0 00 00 00 00 00 00 00 00 00 00 00 00 Q0 P 5 MOSI Go aa E e Read register 8 Yaw Pitch Roll Mo M a a e R 13064 1801 790 shown as hex SPI Transaction 2 SCK 16 bytes a rs OAC SMO OMOO MOO MOO MOCO MOO MO OM UO O O OO o oo P 7 MOSI O eo ae a Read Register 8 Yaw Pitch Roll miso IE E a a Pitch Roll oea iso 7 shown as hex At first the device would be initialized by sending the eight bytes 01 08 00 00 00 00 00 00 requesting a read of the yaw pitch roll register The response from the second transaction would be the response to the requested yaw pitch roll from the first transaction The minimum time required between SPI transactions is 50 us AA www vectornav com 32 102 VN 100 User Manual UMO001 6 Communication Protocol The following sections describe the serial and SPI data protocol used by the VN 100 6 1 Numeric Formats Floating point numbers displayed as ASCII text are presented in two formats single
82. rently add some delay to the input measurement The adaptive filtering gain adjusts the maximum allowed AC disturbance amplitude for the measurement prior to entering the attitude filter The larger the allowed disturbance the less filtering that will be applied The smaller the allowed disturbance the more filtering will be applied e This parameter can be adjusted from 0 to 10 e The minimum value of zero turns off all adaptive filtering e The maximum value of 10 will apply maximum filtering Keep in mind that regardless of this setting the adaptive filtering stage will apply only the minimal amount of filtering necessary to get the job done As such this parameter provides you with the ability to set the maximum amount of delay that you are willing to accept in the input measurement 2 17 Magnetic Hard Soft Iron Calibration Hard and soft iron distortions are caused by ferromagnetic materials that are close to and rigidly attached to the same object as the sensor Hard iron distortions create an additive magnetic field and add directly to the measured Earth s magnetic field Hard iron objects include anything that is either magnetic or has been magnetized Soft iron distortion comes from objects made from materials such as iron cobalt and nickel which distort the direction of an existing magnetic field Because their effect on the field is a function of their direction relative to the Earth s magnetic field compensating for both hard and
83. ronous messages 1 aiene Pe Provides the ability to append the status to the end of the serial asynchronous messages 2 Pleuni ae Provides the ability to append a counter to the end of the SPI packets 3 epistatue Fou Provides the ability to append the status to the end of the SPI packets 4 SerialChecksum Cua ea Choose the type of checksum used for serial communications 5 SPIChecksum U1 Choose the type of checksum used for the SPI communications 6 ErrorMode u4 Choose the action taken when errors are generated 7 31 1 SerialCount The SerialCount field provides a means of appending a time or counter to the end of all asynchronous communication messages transmitted on the serial interface The values for each of these counters come directly from the Synchronization Status Register With the SerialCount field set to OFF a typical serial asynchronous message would appear as the following SVNYPR 010 071 000 278 002 026 60 With the SerialCount field set to one of the non zero values the same asynchronous message would appear instead as SVNYPR 010 071 000 278 002 026 T1162704 2F When the SerialCount field is enabled the counter will always be appended to the end of the message just prior to the checksum The counter will be preceded by the T character to distinguish it from the status field Table 31 SerialCount Field Mode Value Description we J o Ore SYNCIN_COUNT Syncin Counter
84. ror while in motion 4 RESERVED F4 Reserved for future use Value should remain 0 MP www vectornav com 93 102 VN 100 User Manual UMO001 7 48 Yaw Pitch Roll True Body Acceleration and Angular Rates Register ID 239 Firmware v1 1 and up Access Read Only Comment Attitude solution as yaw pitch roll and the inertial acceleration Size Bytes 36 Example Serial Read Register SVNRRG 239 124 743 001 019 000 203 00 019 00 001 00 039 00 001665 Response 00 000785 00 000647 55 Byte Number Offset Name Format Unit Description 0 Calculated attitude heading angle in degrees 4 Calculated attitude pitch angle in degrees 8 Rol F4 deg Calculated attitude roll angle in degrees 12 Acceleration estimate in the body X axis 16 Acceleration estimate in the body Y axis 20 Acceleration estimate in the body Z axis 24 Calibrated un compensated angular rate in the body X axis 28 Calibrated un compensated angular rate in the body Y axis 32 Calibrated un compensated angular rate in the body Z axis MP www vectornav com 94 102 VN 100 User Manual UMO001 7 49 Yaw Pitch Roll True Inertial Acceleration and Angular Rates Yaw Pitch Roll True Inertial Acceleration and Angular Rates Register ID 240 Firmware v1 1 and up Access Read Only Comment Attitude solution as yaw pitch roll and the inertial acceleration Size Bytes 36 Example Serial Read Register
85. s better pitch roll accuracy but with more sensitivity to acceleration interference Level of adaptive tuning for X Axis Level of adaptive tuning for Y Axis Level of adaptive tuning for Z Axis Level of adaptive filtering for X Axis Level of adaptive filtering for Y Axis Level of adaptive filtering for Z Axis www vectornav com 85 102 VN 100 User Manual UMO01 7 40 VPE Accelerometer Advanced Tuning Register ID 39 Firmware v1 1 and up Access Read Write Comment Provides advanced control of the adaptive filtering and tuning for the accelerometer Size Bytes 36 Example Serial Read Register Response Byte Number Offset Name Format Range Description MinFilteringX 0 10 Minimum allowed level of filtering for X Axis MinFilteringY 0 10 Minimum allowed level of filtering for Y Axis SVNRRG 39 0 10 0 10 0 10 1 2 1000 66 8 Minimum allowed level of filtering for Z Axis 12 Maximum allowed level of filtering for X Axis 16 Maximum allowed level of filtering for Y Axis 20 Maximum allowed level of filtering for Z Axis 24 Controls the rate the filtering level is allowed to change 28 Width of disturbance tuning window 32 MaxTuning F4 Maximum allowed estimated measurement variance AA www vectornav com 86 102 VN 100 User Manual UMO001 7 41 VPE Gyro Basic Tuning Register ID 40 Firmware v1 1 and up Access Read Write Comment Provides basic control
86. s internal clock to run the internal filtering loop which is fixed at 200Hz An external signal can be used in place of the internal clock provided that the VN 100 can still be run at precisely 200Hz It is important to note that the VN 100 filter loop must run at precisely 200Hz at all times During the integration step of the onboard filtering a fixed time step of 5ms is always assumed If a signal other than 200Hz is used to run the filter then you will have significant performance degradation due to incorrect propagation of the gyro rates It is possible to run the VN 100 filter loop at 200Hz using a higher frequency signal provided that the signal frequency is a multiple of the required 200Hz For example a 1kHz signal can be used by setting the SyncinSkipFactor in the Synchronization Control Register Section 7 33 equal to 4 With this setting the device will trigger on every 5th edge selected by the SyncinEdge field Figure 4 Using an external clock Clock Generator To set the VN 100 to operate using an external clock send the following command to the device Interface Write Register Set to Use External Clock SVNWRG 32 1 0 0 0 1 0 0 500000 0 5E 02 20 00 00 01 00 00 00 00 00 00 00 01 00 00 00 00 07 A1 20 00 00 00 00 KA www vectornav com 20 102 VN 100 User Manual UMO001 3 6 Using the VN 100 with external sensors Normally the VN 100 uses the onboard gyroscopes accelerometer and magnetometer to compute its attitude s
87. soft iron distortions isn t trivial and requires collecting data while the sensor is rotated in many different orientations The VPE utilizes a separate Kalman filter running in the background to perform real time compensation for hard and soft iron disturbances The hard and soft iron calibration can either be run once and the parameters saved to flash memory for future use or the calibration can be left running in the background to continuously compensate for possible changes in the hard and soft iron distortions KA www vectornav com 16 102 VN 100 User Manual UMO001 O For more information on how to turn on off the hard soft iron calibration and adjust its settings see the Magnetic Calibration Control Register Section 7 44 MP www vectornav com 17 102 VN 100 User Manual UMO001 3 Operation and Usage Scenarios The following section provides an overview as to the various ways the VN 100 sensor can be used It describes in detail how the VN 100 can be used as an IMU or an orientation sensor various synchronization options and installation and alignment procedures This section should serve as a preliminary guide that will get you up and running with the VN 100 For more implementation specific details see our application notes section on the website 3 1 Using the VN 100 as an Inertial Measurement Unit As an Inertial Measurement Unit IMU the VN 100 is utilized to provide only calibrated acceleration angular rates and ma
88. ster will replace the corresponding internal sensor measurements with the ones provided All fields other than the ones corresponding to the external sensor will remain read only and will their values will remain unaffected by the write register command For these other values you can provide a zero value Below shows an example of how to update the external magnetometer at each time step Figure 5 Provide the VN 100 with External Magnetometer Measurements a Write Register Write External Magnetometer Measurement Serial SVNWRG 252 1 0 0 1 1 8 0 0 0 0 0 0 0 79 02 FC 00 00 00 00 80 3F CD CC CC BD 66 66 E6 3F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Figure 6 Provide the VN 100 with External Accelerometer Measurements Interface Write Register Write External Magnetometer Measurement SVNWRG 252 0 0 0 0 1 1 5 9 81 0 0 0 0 79 SPI 02 FC 00 00 00 00 00 00 00 00 00 00 00 00 00 00 CD CC CC 3D 00 00 CO 3F C3 F5 1C C1 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 AA www vectornav com 21 102 VN 100 User Manual UMO001 How to deal with different sampling rates The VN 100 will sample the IMU Measurement Register Section 7 52 at the beginning of each filter loop Since the filter loop always runs at 200Hz this will occur every 5ms If the external magnetometer measurements are updated at a rate slower than 200Hz it is possible that the IMU Measurement Register may not be updated every
89. stimate of the gyro bias The VPE will constantly monitor the stability of the magnetic field and when it sees that its direction is reasonably stable the VPE will maintain a stable heading estimate Over long periods of time under conditions where the magnetic field direction changes frequently in Relative Heading mode it is possible for the VN 100 to accumulate some error in its reported heading relative to true North In this mode the VPE will not attempt to correct for this accumulated heading error Relative Heading mode does not assume that the Earth s magnetic field is the only long term magnetic field present As such this mode is capable of handling a much wider range of magnetic field disturbances while still maintaining a stable attitude solution Relative Heading mode should be used in 2 www vectornav com 13 102 VN 100 User Manual UMO001 situations where the most important requirement is for the attitude sensor is to maintain a stable attitude solution which minimizes the effect of gyro drift while maintaining a stable and accurate pitch and roll solution Since the Relative Heading mode assumes that other magnetic disturbances can be present which are indistinguishable from the Earth s field Relative Heading mode cannot always ensure that the calculated heading is always referenced to Earth s magnetic north o Relative Heading Mode Advantages e Capable of handling short term and long term magnetic interference e Can handle sig
90. surements are available Ground Input signal used to zero the attitude of the sensor If high at reset the TARE RESTORE device will restore to factory default state Internally held low with 10k resistor Input signal for synchronization purposes Software configurable to 7 SYNC_IN either synchronize the measurements or the output with an external device 8 TX2_TTL Serial UART 2 data output from the device at TTL voltage level 3V 9 RX2_TTL Serial UART 2 data into the device at TTL voltage level 3V RESV This pin should be left unconnected Figure 8 VN 100 Rugged External Connector 5 4 3 2 1 AA www vectornav com 26 102 VN 100 User Manual UMO001 4 1 2 1 VN 100 Rugged Power Supply The nominal power supply for the VN 100 Rugged is 5V DC e The VN 100 Rugged internally has overvoltage protection set at a fixed voltage of 5 8V Upon an overvoltage event the protection circuitry will disable power to the VN 100 to reduce possibility of damage to the voltage regulator onboard the VN 100 4 1 2 2 VN 100 Rugged Serial UART Interface Table 9 Serial I O Specifications Specification Min Typical _Input low level voltage 25v Input high level voltage Output resistance 3000 10 MO Data rate 4 1 2 3 VN 100 Rugged Reset SynciIn Out and Other General I O Pins Table 10 NRST Specifications Specification Min Typical Max Input low level voltage osv f o8v Input high level voltage
91. tcictevonecsvind busiiaeyiedianddsdiwebbenddattdens uenboadueaqeetienubiedseaces 12 Del Attitude EStIMat ON seriski inisinia se kadena kas a niapi akanaka Taaa aeaaea E NEES 12 2 8 VPE Magnetic Heading Modes ccccccsseesssesssesssesseesseesesesseeseeesseeees 12 2 9 Absolute Heading Mode iiss odcssccicicnasecteinsdacincvesaduengestieesenteniavtdcaasauuecninerteskemutlawsanues 13 210 Relative Heading ModE sssi siersccasusretersssnadealesuwecn anya Gd senspuadenwseeachevadwatiesevdicvencvecdecibewdens 13 2 11 Indoor Heading WOE sa reicicvesicincadeatedsncpnceaandeccebandeacdeeaieatsbiecdacennapenntndeadunage dative 14 2 12 Overview of Heading MOodeSsuissicesniirsriicniiiscre siii 15 2 13 VPE Adaptive Filtering and Tuning SettingS c sccsssesseeseeeseeeees 15 2 14 Static Measurement Uncertainty ccccccccccccecsssesssecesececessessseseseeeeseessesseaeeeeeesens 15 2 15 Adaptive Tuning GiM seipiccsscceceinrcpiceastywnaciudntcenauprdeeiadsinnntiaieure aamemtianbeeioGemmemgntecs 16 2 16 Adaptive Filtering Gain sicsecacscsdsiasceas seansinaiadlsdeaxeindeds lanes saaaeeenadiamencaiecs acres iceneaue 16 2 17 Magnetic Hard Soft Iron Calibration ccccccccessssseceeeessseeeecesssseeeeeeeeas 16 3 Operation and Usage Scenarios csssccssscsssccsscecssccesscessccsscees 18 3 1 Using the VN 100 as an Inertial Measurement Uniit ccccceeeeeeeeeees 18 3 2 Using the VN 100 as an Orientation Sensor
92. tf Scanf Example Yaw Pitch Roll 08 3f 082 763 9 10 11 12 13 14 15 09 6f 0 053362 10 13 15 17 20 27 07 4f 0 3647 11 13 14 18 20 27 07 3f 09 091 Angular Rate 12 14 15 19 20 27 09 6f 00 001786 6 4 System Commands This section describes the list of commands available on the VN 100 module All commands are available in both ASCII text UART and binary SPI command formats The table below lists the commands available along with some quick information about the commands The Text ID is used to specify the command when using the text command format and the Binary ID is KA www vectornav com 33 102 VN 100 User Manual UMO001 used to specify the command when using the binary command format More details about the individual commands can be found in the referenced section Table 15 List of Available Commands Command Name Text ID Binary ID Section Restore Factory Settings vnRFs_ oxo4 o 6 4 1 Read Register Command This command allows the user to read any of the registers on the VN 100 module see Section 7 for the list of available registers The only required parameter is the ID of the register to be read The first parameter of the response will contain the same register ID followed by a variable number of parameters The number of parameters and their formatting is specific to the requested register Refer to the appropriate register section contained in Section 7 for details on this formatting
93. tometer Max TFA volt Magy TFA volt 8 Raw voltage measured on Z axis magnetometer 12 Raw voltage measured on X axis accelerometer 16 Raw voltage measured on Y axis accelerometer 20 Raw voltage measured on Z axis accelerometer 24 Raw voltage measured on X axis gyro 28 Raw voltage measured on Y axis gyro 32 Raw voltage measured on Z axis gyro 36 Temperature Sensor F4 volt Raw voltage measured on temperature sensor AA www vectornav com 97 102 VN 100 User Manual UMO001 7 52 Calibrated IMU Measurements Register ID 252 Firmware v0 1 and up Access Read Only Comment Provides the calibrated IMU measurements Size Bytes 40 Example Serial Read Register Response SVNRRG 252 1 0678 0 2539 3 0652 00 017 00 341 09 820 0 019193 0 031246 0 005292 25 8 40 Number Format Byte Offset Name 0 MagxX 4 MagyY 8 MagZ 12 AccelX 16 AccelY 20 AccelZ 24 GyroxX 28 GyroY 32 GyroZ 36 Temperature Sensor Unit Description Calibrated magnetic X axis measurement Calibrated magnetic Y axis measurement Calibrated magnetic Z axis measurement Calibrated acceleration X axis measurement Calibrated acceleration Y axis measurement Calibrated acceleration Z axis measurement Calibrated X axis angular rate Calibrated Y axis angular rate Calibrated Z axis angular rate Calibrated temperature sensor 3 n NJ n aS bee w jov W O E o NINTH
94. ual UMO001 1 3 Surface Mount Package For embedded applications the VN 100 is available in a miniature surface mount package Features e Small Size 24 x 22 x 3 mm e Single Power Supply 3 2 to 5 5 V e Communication Interface Serial TTL amp SPI e Low Power Requirement lt 165 mW 3 3V 1 4 Rugged Package The VN 100 Rugged consists of the VN 100 sensor installed in a robust precision aluminum enclosure Features e Precision aluminum enclosure e Locking 10 pin connector e Mounting tabs with alignment holes e Compact Size 33 x 26 x9 mm e Single Power Supply 4 5 to 5 5 V e Communication Interface Serial RS 232 1 5 Surface Mount Development Kit The VN 100 Development kit provides the VN 100 surface mount sensor installed onto a small PCB providing easy access to all of the features and pins on the VN 100 Communication with the VN 100 is provided by either USB or RS 232 serial communication ports A 20 pin header provides easy access to all of the important pins The development kit also includes all of the necessary cables documentation and support software Features e Pre installed VN 100 Sensor e Onboard USB gt Serial converter e Onboard TTL gt RS 232 converter e 20 pin 0 1in header for access to VN 100 pins e Power supply jack 5V Can be power from USB e Board Size 2 9 x 2 9 KA www vectornav com 8 102 VN 100 User Manual 1 6 VN 100 Rugged IMU AHRS Development Kit The VN 100 Rugged de
95. us features relating to the onboard attitude filtering algorithm Size Bytes 4 Example Serial Read Register Response Byte Number Offset Name Format Unit Description 0 Enable U1 Enable Disable the Vector Processing Engine VPE HeadingMode U1 Heading mode used by the VPE FilteringMode U1 Filtering Mode used by the VPE TuningMode U1 Tuning Mode used by the VPE Table 46 Enable SVNRRG 35 1 3 1 1 77 WINIR Value State Po osae Table 47 HeadingMode Value Mode Absolute Heading Relative Heading Indoor Heading Table 48 Filtering Mode Value Mode E OFF MODE 1 Table 49 Tuning Mode Value Mode ao OFF MODE 1 NA www vectornav com 82 102 VN 100 User Manual UMO001 7 37 VPE Magnetometer Basic Tuning VPE Magnetometer Basic Tuning Register ID 36 Firmware v1 1 and up Access Read Write Comment Provides basic control of the adaptive filtering and tuning for the magnetometer Size Bytes 36 Example Serial Read Register Response Byte Number Offset Name Format Min Max Description Base Magnetic Tuning X Axis 0 10 This sets the level of confidence placed in the magnetometer 0 BaseTuningX F4 0 10 X axis when no disturbances are present A larger number provides better heading accuracy but with more sensitivity to magnetic interference Base Magnetic Tuning Y Axis 0 10 This sets the level of confidence place
96. velopment kit includes the Rugged sensor along with all of the necessary cables required for operation Two cables are provided in each development kit one for RS 232 communication and a second custom cable with a built in USB converter The kit also includes all of the relevant documentation and support software Features e 1VN 100 Rugged Sensor e 110 foot RS 232 cable e 16 foot USB connector cable 1 6 1 1 Sensor Coordinate System UMo01 The VN 100 uses a right handed coordinate system A positive yaw angle is defined as a positive right handed rotation around the Z axis A positive pitch angle is defined as a positive right handed rotation around the Y axis A positive roll angle is defined as a positive right handed rotation around the X axis The axes direction with respect to the VN 100 module is shown in Figure 1 Figure 1 VN 100 Coordinate System KAA www vectornav com Pitch 9 102 VN 100 User Manual UMO001 2 VN 100 Vector Processing Engine 221 Overview Along with the 9 axis calibrated sensor array the VN 100 also incorporates onboard a 32 bit ARM processor running VectorNav s general purpose attitude estimation algorithm known as the Vector Processing Engine The Vector Processing Engine VPE combines the measurements available from the accelerometers magnetometers and gyroscopes to derive a high accuracy 3D orientation solution with minimal gyro drift for both static and dynamic conditions Vector
97. z F4 rad s Calibrated amp filter bias compensated angular rate in z axis D gt g la w lt T gt 5 o w N T AA www vectornav com 57 102 VN 100 User Manual UMO001 7 17 Attitude Directional Cosine Orientation Matrix Attitude Directional Cosine Matrix RegisterID 16 Firmware v0 1 and up Access Read Only The calculated attitude as a directional cosine matrix 36 Comment Size Bytes Example Serial Read Register Response Byte Number Offset Name Format Unit Description SVNRRG 16 9 941386E 01 1 080712E 01 3 024663E 03 1 081114E 01 9 935566E 01 3 401868E 02 6 712652E 04 3 414628E 02 9 994167E 01 0F Le a 4 cfoaj ra ik as ee ee 12 cio 16 cay Fa 20_ cit2 SSS 2g e Ien rT This register contains the attitude directional cosine matrix This matrix is a valid 3x3 rotation matrix Nine parameters are returned from this command and the terms are mapped to a 3x3 matrix as follows c00 C01 C02 DCM C10 C11 C12 C20 C21 C22 The ordering of this register s nine values is shown below All nine numbers are represented as floating point AA www vectornav com 58 102 VN 100 User Manual 7 18 Magnetic Measurements Magnetic Measurements Register ID Comment Size Bytes Example Serial Read Register Response Byte Offset Name 0 4 8 17 Firmware v0 1 and up A

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