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DMU380ZA Series

User’s Manual

Doc# 7430-3810 Rev. 02

Page iii

7.2.9

Error Response ............................................................................................54

Output Packets (Polled) ......................................................................................54

7.3

7.3.1

Identification Data Packet ...........................................................................54

7.3.2

Version Data Packet ....................................................................................54

7.3.3

Test 0 (Detailed BIT and Status) Packet ......................................................55

Output Packets (Polled or Continuous) ...............................................................55

7.4

7.4.1

Scaled Sensor Data Packet 0 .......................................................................55

7.4.2

Scaled Sensor Data Packet 1 (Default IMU Data) .......................................56

7.4.3

Angle Data Packet 1 (Default AHRS Data) ................................................57

7.4.4

Angle Data Packet 2 (Default VG Data) .....................................................58

7.4.5

Nav Data Packet 0 .......................................................................................59

7.4.6

Nav Data Packet 1 (Default INS Data) ........................................................60

7.4.7

Angle Data Packet B1 (Custom VG Data) ..................................................61

7.4.8

Angle Data Packet B2 (Custom VG Data) ..................................................62

DMU380ZA Advanced UART Port Commands .......................................................63

Configuration Fields ...........................................................................................63

8.1

Continuous Packet Type Field ............................................................................63

8.2

Digital Filter Settings ..........................................................................................64

8.3

Orientation Field .................................................................................................64

8.4

User Behavior Switches ......................................................................................66

8.5

Hard and Soft Iron Values ..................................................................................66

8.6

Heading Track Offset ..........................................................................................66

8.7

Commands to Program Configuration ................................................................67

8.8

8.8.1

Write Fields Command ................................................................................67

8.8.2

Set Fields Command ....................................................................................68

Read Fields Command ........................................................................................69

8.9

Read Fields Response .....................................................................................69

8.10

Get Fields Command .......................................................................................69

8.11

Get Fields Response ........................................................................................70

8.12

DMU380ZA Advanced UART Port BIT ...................................................................71

Built In Test (BIT) and Status Fields ..................................................................71

9.1

Master BIT and Status (BITstatus) Field ............................................................73

9.2

hardwareBIT Field ..............................................................................................74

9.3

hardwarePowerBIT Field ....................................................................................74

9.4

hardwareEnvironmentalBIT Field ......................................................................74

9.5

comBIT Field ......................................................................................................74

9.6

Summary of Contents for AHRS380ZA

Page 1: ...PI or UART Interface Update Rate 1Hz to 200Hz 1KHz Clock Synch Input Miniature Package 24 x 37 x 9 5 mm Lightweight 17 g Low Power Consumption 250 mW Wide Temp Range 40C to 85C High Reliability MTBF 5...

Page 2: ...e to display record playback and analyze all of the AHRS380ZA Attitude Heading Reference System parameters NAV VIEW can also be used to set a wide range of user configurable fields in the AHRS380ZA to...

Page 3: ...DMU380ZA Series USER MANUAL Document Part Number 7430 3810 02 MEMSIC Inc 1759 McCarthy Blvd Milpitas CA 95035 Tel 408 964 9700 Fax 408 854 7702 email infoca memsic com website www memsic com...

Page 4: ...siles rockets and or UAV s of 300km or greater range or any other activity prohibited by the Export Administration Regulations is expressly prohibited without the written consent of MEMSIC and without...

Page 5: ...dvanced Settings 12 IMU380ZA Theory of Operation 12 3 2 3 2 1 IMU380ZA Advanced Settings 13 3 2 2 IMU380ZA Built In Test 14 VG380ZA Theory of Operation 14 3 3 3 3 1 VG380ZA Advanced Settings 16 4 3 2...

Page 6: ...7 4 Magnetic Alignment 42 Suggested Operation 43 5 8 6 DMU380 UART Port Interface Definition 46 General Settings 46 6 1 Number Formats 46 6 2 Packet Format 47 6 3 6 3 1 Packet Header 47 6 3 2 Packet...

Page 7: ...VG Data 61 7 4 8 Angle Data Packet B2 Custom VG Data 62 8 DMU380ZA Advanced UART Port Commands 63 Configuration Fields 63 8 1 Continuous Packet Type Field 63 8 2 Digital Filter Settings 64 8 3 Orienta...

Page 8: ...ensorStatusEnable Field 78 10 Warranty and Support Information 79 10 3 1 Authorization 79 10 3 2 Identification and Protection 79 10 3 3 Sealing the Container 80 10 3 4 Marking 80 10 3 5 Return Shippi...

Page 9: ...Series User s Manual Doc 7430 3810 Rev 02 Page v Appendix B NMEA Message Format 93 GGA GPS fix data 93 Appendix C Sample Packet Parser Code 95 Overview 95 Code listing 96 Appendix D Sample Packet Deco...

Page 10: ...e given throughout the manual to help the reader understand the terminology IMPORTANT This symbol defines items that have significant meaning to the user WARNING The user should pay particular attenti...

Page 11: ...nd features of your DMU380ZA Series system For example if you have purchased an INS380ZA you should read not only the section on the INS380ZA but also familiarize yourself with the theory of operation...

Page 12: ...MEMS angular rate sensing and three axes of MEMS linear acceleration sensing These sensors are based on rugged field proven silicon bulk micromachining technology Each sensor within the cluster is ind...

Page 13: ...02 Page 3 choice is user controlled by grounding the appropriate pin on the connector The DMU380 low level UART output data port is supported by MEMSIC s NAV VIEW 3 X a powerful PC based operating to...

Page 14: ...pin definitions are defined in Table 3 Table 3 DMU380ZA Interface Connector Pin Definition Pin Signal 1 Reserved factory use only 2 Synchronization Input 1KHz Pulse used to synchronize SPI Com 1PPS 3...

Page 15: ...ontrols apply only to data being output over the UART port and the SPI output controls apply only to data being output over the SPI port 2 1 4 External GPS Aiding VG380ZA AHRS380ZA and INS380ZA The VG...

Page 16: ...om an external GPS receiver then Pin 2 can be used as a sync pulse to force synchronization of sensor data collection to a 1 KHz rising edge signal for output over the SPI port 2 1 4 3 External GPS Re...

Page 17: ...for each member of the DMU380ZA Series starting with the basic IMU380ZA and then reviewing each major variant VG AHRS and INS with their associated additional features outputs and performance Table 5...

Page 18: ...rithm from data collected during manufacturing Accelerometer and rate gyro sensor bias shifts over temperature 40 0 C to 71 0 C are compensated and verified using calibrated thermal chambers and rate...

Page 19: ...oducts Built In Test and Status data is available in the measurement packet or via the special Status Packet T0 As shown in the software block diagram the DMU380ZA Series has a unit setting and profil...

Page 20: ...t correction for the attitude i e roll and pitch only is a 3 axis accelerometer This is the default configuration for the VG product X Y Z Body Accelerometers 6 DOF Sensor Cluster Sensor Calibration A...

Page 21: ...e 6 and Figure 7 As with many elements of the DMU380ZA Series the coordinate system is configurable with either NAV VIEW or by sending the appropriate serial commands over the UART port These configur...

Page 22: ...or a positive rotation around the z axis turn right The angles are defined as standard Euler angles using a 3 2 1 system To rotate from the body frame to an earth level frame roll first then pitch and...

Page 23: ...I port please see section 5 Table 6 IMU380ZA Advanced Settings Setting Default Comments Baud Rate 38 400 baud 9600 19200 57600 also available Packet Type S0 S1 also available Packet Rate 100Hz This se...

Page 24: ...IT Status Definition BITstatus Field Bits Meaning Category masterFail 0 0 normal 1 fatal error has occurred BIT HardwareError 1 0 normal 1 internal hardware error BIT comError 2 0 normal 1 communicati...

Page 25: ...e measurement for the EKF when the VG380ZA is in quasi static motion to correct roll and pitch angle drift and to estimate the X and Y gyro rate bias Because the gravity vector has no horizontal compo...

Page 26: ...possible orientation settings The default setting points the connector AFT Filter Settings 5 10 20 50 Hz 20 Hz The low pass filters are set to a default of 5Hz for the accelerometers and 20 Hz for th...

Page 27: ...ds a given Turnswitch threshold the feedback gains from the accelerometer signals for attitude correction are reduced because they are likely corrupted BIT See 4 3 2 4 3 2 VG380ZA Built In Test As wit...

Page 28: ...VG380ZA the dynamic roll and pitch measurements are stabilized using the accelerometers as a long term gravity reference Unlike the AHRS400 and earlier MEMSIC AHRS Series products the AHRS380ZA can be...

Page 29: ...alization phase lasts approximately 60 seconds and the initialization phase can be monitored in the softwareStatus BIT transmitted by default in each measurement packet After the initialization phase...

Page 30: ...in the BIT word is transmitted in every measurement packet When the AHRS380ZA has not been properly calibrated this softwareError bit will be set to fail high The current release of this software does...

Page 31: ...level can be high and it can prove helpful to filter accelerometers Freely Integrate OFF The Freely Integrate setting allows a user to turn the AHRS380ZA into a free gyro In free gyro mode the roll p...

Page 32: ...80ZA Turning off the dynamic motion setting results in a higher gain state that uses the accelerometer feedback heavily During periods of time when there is known low dynamic acceleration this switch...

Page 33: ...be configured to go high during a turn In other words the turnSwitch will turn on the softwareStatus bit In the AHRS380ZA the turnSwitch is by default set at 0 5 deg sec about the Z axis INS380ZA The...

Page 34: ...lock time depends on the antenna s view of the sky and the number of satellites in view The processor performs time triggered trajectory propagation at 100Hz and will synchronize the sensor sampling w...

Page 35: ...Type packets are output If polled mode is desired then select Quiet If Quiet is selected the INS380ZA will only send measurement packets in response to GP commands Orientation See Figure 6 and Figure...

Page 36: ...e a rotational rate on any of the three axes exceeds the maximum range The default setting is OFF for the INS380ZA Algorithm reset returns the INS380ZA to a high gain state where the INS380ZA rapidly...

Page 37: ...details for configuring the masterStatus flags Table 13 shows the BIT definition and default settings for BIT programmable alerts in the INS380ZA Table 13 INS380ZA Default BIT Status Definitions BITs...

Page 38: ...tions Table 14 Recommended Advanced Settings for Fixed Wing Aircraft Recommended Product AHRS380ZA or INS380ZA Recommended Settings Dynamic Condition Pre launch or known straight and level un accelera...

Page 39: ...cal mechanism of rotors generating the aerodynamic forces and moments Table 15 provides the recommended advanced settings for two different dynamic conditions Table 15 Recommended Advanced Settings fo...

Page 40: ...s XY Filter Accel 5 Hz 5 Hz Z Filter Accel 5 Hz 5 Hz Filter Rate Sensor 20 Hz 20 Hz When not in distorted magnetic environment Water Vehicle 4 5 Water vehicle is a craft or vessel designed to float o...

Page 41: ...s transmitted from its landing gear Climb is the phase of a flight after take off consisting of getting the aircraft to the desired flight level altitude More generally the term climb means increasing...

Page 42: ...CCEL R 0x0A N A X Axis Accelerometer Output Y_ACCEL R 0x0C Y Axis Accelerometer Output Z_ACCEL R 0x0E Z Axis Accelerometer Output X_MAG R 0x10 N A X Axis Magnetometer Output Y_MAG R 0x12 Y Axis Magnet...

Page 43: ...scale factor ANG_SOFT_IRON R 0x4E 0x0000 Soft iron angle MAG_ALIGN R W 0x50 0x51 N A See Table 29 Magnetic alignment control and status MANUF_CODE R 0x52 0x1310 Manufacturing code indicating year and...

Page 44: ...A consist of either Sixteen zero bits 0x0000 to complete the read of a single register The address of another register followed by a zero byte This permits back to back reads of data registers Single...

Page 45: ...st mode the DMU380ZA returns predefined blocks of data in single groups referred to as data packets without the need to send multiple read commands These groups vary from eight to nineteen words in le...

Page 46: ...n burst mode subsequent reads writes will be out of sync with the SPI transfer cycle of the DMU380ZA Figure 11 Multiple Register Read via Burst Mode Operational notes 1 When combining polled and burst...

Page 47: ...RATE_TEMP 0x16 Rate sensor temperature information twos complement format conversion Tout C Vout 0 7311 C LSB 31 0 C BOARD_TEMP 0x18 System temperature information twos complement format conversion T...

Page 48: ...Axis self test bit 0 Pass 1 Fail 13 Accelerometer X Axis self test bit 0 Pass 1 Fail 12 Rate Sensor Z Axis self test bit 0 Pass 1 Fail 11 Rate Sensor Y Axis self test bit 0 Pass 1 Fail 10 Rate Sensor...

Page 49: ...with the value to be written to the register e g 0xB504 see Table 25 for a description of the self test register Figure 12 illustrates the sensor self test command sent over SPI Figure 12 Single Regis...

Page 50: ...temporary bias to determine if they are responding correctly Once self test completes the self test bit bit 10 is reset to indicate that the test is finished Results of the self test are store in the...

Page 51: ...ate sensor scaling and digital low pass filter configuration are combined into a single 16 bit register at memory location 0x38 individual bits are assigned according to Table 27 Note these settings a...

Page 52: ...sec 400 LSB sec 125 0 sec 200 LSB sec 250 0 sec 100 LSB sec The digital low pass filter register sets the type and cutoff frequency of the filter applied to the scaled sensor data The default setting...

Page 53: ...o the EEPROM The Kalman filter algorithm is reset to stabilization mode It remains in this state for five seconds to allow the user to bring the system to rest while the initialization process complet...

Page 54: ...cription Value Units fCLK SPI clock frequency 2 max MHz tDELAY Time between successive clock cycles Figure 16 9 min usec tSU NSS nSS setup time prior to clocking data Figure 17 133 nsec th NSS nSS hol...

Page 55: ..._________________________________________________________________ Doc 7430 3810 Rev 02 Page 45 Figure 17 SPI Timing Diagram bit 13 MSB bit 14 bit 1 LSB LSB bit 1 MSB bit 13 bit 14 tSU NSS th NSS tV MI...

Page 56: ...de available under certain conditions Please contact your MEMSIC representative for more information General Settings 6 1 The serial port settings are RS232 with 1 start bit 8 data bits no parity bit...

Page 57: ...ications with the DMU380ZA Series unit require the 2 byte CRC Note A DMU380ZA Series unit will also respond to a ping command using the full packet formation with payload 0 and correctly calculated CR...

Page 58: ...al value See Appendix C for sample code that implements the 16 bit CRC algorithm 6 3 6 Messaging Overview Table 33 summarizes the messages available by DMU380ZA Series model Packet types are assigned...

Page 59: ...ut Message IMU380ZA 209 409 AHRS INS S1 0x5331 24 Scaled Sensor 1 Data Output Message ALL A1 0x4131 32 Angle 1 Data Output Message AHRS INS A2 0x4132 30 Angle 2 Data Output Message VG AHRS INS N0 0x4E...

Page 60: ...DMU380ZA Series User s Manual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 50 GF 0x4746 numFields 4 1 Get Fields Response Reply Message ALL...

Page 61: ...g command 7 1 3 Echo Command Echo CH 0x4348 Preamble Packet Type Length Payload Termination 0x5555 0x4348 N echo payload CRC U2 The echo command allows testing and verification of the communication li...

Page 62: ...Packet Type Length Termination 0x5555 0x4152 0x00 CRC U2 The unit will send this packet in response to an algorithm reset command 7 2 4 Calibrate Command Calibrate WC 0x5743 Preamble Packet Type Leng...

Page 63: ...55 0x5743 0x02 WC payload CRC U2 The unit will send this packet in response to a calibrate request if the procedure can be performed or initiated WC Payload Contents Byte Offset Name Format Scaling Un...

Page 64: ...String 8 bit Ascii values followed by the firmware part number string delimited by a whitespace ID Payload Contents Byte Offset Name Format Scaling Units Description 0 serialNumber U4 Unit serial numb...

Page 65: ...mentalBIT U2 Hardware Environmental BIT Field 8 comBIT U2 communication BIT Field 10 comSerialABIT U2 Communication Serial A BIT Field 12 comSerialBBIT U2 Communication Serial B BIT Field 14 softwareB...

Page 66: ...e 22 zRateTemp I2 200 2 16 deg C Z rate temperature 24 boardTemp I2 200 2 16 deg C CPU board temperature 26 GPSITOW U2 truncated ms GPS ITOW lower 2 bytes 28 BITstatus U2 Master BIT and Status 7 4 2 S...

Page 67: ...cket 1 Default AHRS Data Angle Data A1 0x4131 Preamble Packet Type Length Payload Termination 0x5555 0x4131 0x20 A1 payload CRC U2 This packet contains angle data and selected sensor data scaled in mo...

Page 68: ...ccel I2 20 2 16 g Z accelerometer 18 xMag I2 20 2 16 Gauss X magnetometer 20 yMag I2 20 2 16 Gauss Y magnetometer 22 zMag I2 20 2 16 Gauss Z magnetometer 24 xRateTemp I2 200 2 16 Deg C X rate temperat...

Page 69: ...p I2 200 2 16 deg C Y rate temperature 22 zRateTemp I2 200 2 16 deg C Z rate temperature 24 timeITOW U4 1 ms DMU ITOW sync to GPS 28 BITstatus U2 Master BIT and Status 7 4 5 Nav Data Packet 0 Nav Data...

Page 70: ...26 altitudeGPS I2 2 14 2 16 m GPS altitude 100 16284 28 GPSITOW U2 truncated ms GPS ITOW lower 2 bytes 30 BITstatus U2 Master BIT and Status 7 4 6 Nav Data Packet 1 Default INS Data Nav Data N1 0x4E3...

Page 71: ...Vel I2 512 2 16 m s Down velocity 24 longitudeGPS I4 2 pi 2 32 360 2 32 Radians GPS Longitude 28 latitudeGPS I4 2 pi 2 32 360 2 32 Radians GPS Latitude 32 altitudeGPS I2 2 14 2 16 m GPS altitude 100 1...

Page 72: ...et Type Length Payload Termination 0x5555 0x4232 0x0A B2 payload CRC U2 This packet contains selected angle and sensor data B2 Payload Contents Byte Offset Name Format Scaling Units Description 0 roll...

Page 73: ...with valid data from Table 34 below Table 34 Configuration Fields configuration fields field ID Valid Values description Packet rate divider 0x0001 0 1 2 5 10 20 25 50 quiet 100Hz 50Hz 25Hz 20Hz 10Hz...

Page 74: ...U380 family model The default factory axis setting for the IMU380ZA 200 orientation field is Uy Ux Uz which defines the connector pointing in the Z direction and the X direction going from the connect...

Page 75: ...Ux 0x00D3 Uy Uz Ux 0x00DA Uy Uz Ux 0x0111 Ux Uz Uy 0x0118 Ux Uz Uy 0x0124 Uz Ux Uy 0x012D Uz Ux Uy 0x0150 Ux Uz Uy 0x0159 Ux Uz Uy 0x0165 Uz Ux Uy 0x016C Uz Ux Uy The default factory axis setting for...

Page 76: ...hicle is static force high gain corrections 1 vehicle is dynamic use nominal corrections Reserved 6 15 N A Hard and Soft Iron Values 8 6 These fields allow access to hard iron bias and soft iron scale...

Page 77: ...rror response Note that both a write fields and an error response may be received as a result of a write fields command Attempts to write a field with an invalid value is one way to generate an error...

Page 78: ...e Note that both a set fields and an error response may be received as a result of one set fields command Attempts to set a field with an invalid value is one way to generate an error response A table...

Page 79: ...d fields command RF Payload Contents Byte Offset Name Format Scaling Units Description 0 numFields U1 The number of fields to read 1 field0 U2 The first field ID to read 3 field1 U2 The second field I...

Page 80: ...eceived as the result of a get fields command GF Payload Contents Byte Offset Name Format Scaling Units Description 0 numFields U1 The number of fields to get 1 field0 U2 The first field ID to get 3 f...

Page 81: ...re Soft errors are those which must be triggered multiple times within a specified time window to be considered fatal Soft errors are managed using a digital high pass error counter with a trigger thr...

Page 82: ...orithmBIT Field initialization overRange missedIntegrationStep dataError softwareDataBIT Field calibrationCRCError magAlignOutOfBounds masterStatus hardwareStatus hardwareStatus Field unlocked1PPS ena...

Page 83: ...ntermediate signals that are used to determine when the masterStatus flag is asserted hardwareStatus sensorStatus comStatus and softwareStatus masterStatus is the logical OR of these intermediate sign...

Page 84: ...Category inpPower 0 0 normal 1 out of bounds Soft inpCurrent 1 0 normal 1 out of bounds Soft inpVoltage 2 0 normal 1 out of bounds Soft fiveVolt 3 0 normal 1 out of bounds Soft threeVolt 4 0 normal 1...

Page 85: ...1 error Soft Reserved 5 15 N A comSerialBBIT Field 9 8 The comSerialBBIT field See Table 47 contains flags that indicate low level errors with external serial port B the aiding serial port The serial...

Page 86: ...wise OR of this softwareDataBIT field Table 50 DMU380 Software Data BIT Field SoftwareDataBIT Field Bits Meaning Category calibrationCRCError 0 0 normal 1 incorrect CRC on calibration EEPROM data or d...

Page 87: ...hat allows the user to select items of interest that will logically flow up to the masterStatus flag Table 53 DMU380 Software Status Field softwareStatus Field Bits Meaning algorithmInit 0 0 normal 1...

Page 88: ...see BIT and status definitions This field allows the user to determine which low level comStatus field signals will flag the comStatus and masterStatus flags in the BITstatus field Any asserted bits i...

Page 89: ...uipment please contact MEMSIC to obtain a Returned Material Authorization number RMA Be ready to provide the following information when requesting a RMA Name Address Telephone Fax Email Equipment Mode...

Page 90: ...he container 10 3 4 Marking Please write the words FRAGILE DELICATE INSTRUMENT in several places on the outside of the shipping container s In all correspondence please refer to the equipment by the m...

Page 91: ...the CD ROM drive 2 Locate the NAV VIEW folder Double click on the setup exe file 3 Follow the setup wizard instructions You will install NAV VIEW and NET 2 0 framework Connections The DMU380ZA Series...

Page 92: ...Series product and the computer check the power supply and verify that the COM port is not occupied by another device 4 Under the View menu you have several choices of data presentation Graph display...

Page 93: ...log file 1 To playback data select Playback Mode from the Data Source drop down menu at the top 2 Selecting Playback mode will open a text prompt which will allow users to specify the location of the...

Page 94: ...Compass View If the DMU380ZA Series product you have connected is capable of providing heading and angle information see Table 2 NAV VIEW can provide a compass and a simulated artificial horizon view...

Page 95: ...on This button simply provides users with the currently set configuration of the unit and displays the values in the left column of boxes There are three tabs within the Unit Configuration menu Genera...

Page 96: ...Advanced tab at the top of the Unit Configuration window WARNING Users are strongly encouraged to read and thoroughly understand the consequences of altering the settings in the Advanced tab before ma...

Page 97: ...uration window is Bit Configuration See Figure 26 This tab allows the users to alter the logic of individual status flags that affect the masterStatus flag in the master BITstatus field available in m...

Page 98: ...Iron Overview The AHRS and INS380ZA products use magnetic sensors to compute heading Ideally the magnetic sensors would be measuring only earth s magnetic field to compute the heading angle In the rea...

Page 99: ...iron environment in your system using a two dimensional algorithm The AHRS and INS380ZA products will calculate the hard iron magnetic fields and soft iron corrections and store these as calibration c...

Page 100: ...age to stop 5 Once you have completed your rotation you will be given data concerning the calibration accuracy The X and Y offset values indicate how far the magnetic field has been offset due to hard...

Page 101: ...ty Future releases of software will restore this functionality The magnetometer ranges is 4 gauss thus 2 5 gauss is the recommended maximum hardiron that should be tolerated for the installation and s...

Page 102: ...DMU380ZA Series User s Manual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 92 Figure 29 Read Configuration...

Page 103: ...ing Description Format Example GPGGA string GPGGA Message ID GGA protocol header hhmmss ss hhmmss sss 092725 00 UTC Time Current time Latitude dddmm mmmm 4717 11399 Latitude Degrees minutes N characte...

Page 104: ...ual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 94 CR LF End of message Fix Status Description 0 No fix Invalid 1 Standard GPS 2D 3D 2 Differenti...

Page 105: ...trieving 2 bytes from the queue without popping peekByte for retrieving a byte from the queue without popping Pop discard item s from queue Size returns number of items in queue Empty return 1 if queu...

Page 106: ...acket unsigned short packet_type char length unsigned short crc char data 256 XBOW_PACKET QUEUE_TYPE circ_buf FUNCTION process_xbow_packet looks for packets in a queue ARGUMENTS queue_ptr is pointer t...

Page 107: ...hrough minimum length packet if Size queue_ptr 7 return 0 get data length 5th byte of packet dataLength peekByte queue_ptr 4 make sure we can read through entire packet if Size queue_ptr 7 dataLength...

Page 108: ...o queue holding area to be CRCed startIndex is offset into buffer where to begin CRC calculation num is offset into buffer where to stop CRC calculation RETURNS 2 byte CRC unsigned short calcCRC QUEUE...

Page 109: ...val 0 if queue_ptr count MAXQUEUE retval 0 queue is full else queue_ptr count queue_ptr rear queue_ptr rear 1 MAXQUEUE queue_ptr entry queue_ptr rear item retval 1 return retval FUNCTION DeleteQeue re...

Page 110: ...firstIndex return byte FUNCTION peekWord returns 2 byte word from buffer without popping ARGUMENTS queue_ptr is pointer to the queue to return word from index is offset into buffer to which word to r...

Page 111: ...FUNCTION Size ARGUMENTS queue_ptr is pointer to the queue RETURNS return the number of items in the queue int Size QUEUE_TYPE queue_ptr return queue_ptr count FUNCTION Empty ARGUMENTS queue_ptr is poi...

Page 112: ...eries User s Manual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 102 Appendix D Sample Packet Decoding Figure 30 Example payload from Angle Data P...

Page 113: ...DMU380ZA Series User s Manual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 103 Figure 31 Example payload from Scaled Data Packet 1 S1...

Page 114: ...DMU380ZA Series User s Manual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 104 Figure 32 Example payload from Nav Data Packet 1 N1...

Page 115: ...ual ________________________________________________________________________ Doc 7430 3810 Rev 02 Page 105 1759 McCarthy Blvd Milpitas CA 95035 Phone 408 964 9700 Fax 408 854 7702 Website www memsic c...

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