NAVSYNC CW25, User Manual

Page 1: ...CW25 GPS Receiver User Manual Issue R03 Bulletin NS15 UM Revision 03 Date 16 June 2008 ...

Page 2: ... Signals 13 14 5 FEATURES 15 5 1 Power on Reset 15 5 2 Time Transfer 15 5 3 CW25 Embedded Identification 15 5 4 Build Options 15 6 OPERATING MODES 16 6 1 Stand Alone Operation 16 6 2 Net Assisted Operation 16 7 POWER MANAGEMENT 16 7 1 Coma Mode 16 8 COMMUNICATIONS PROTOCOLS 17 30 8 1 Port Configurations 17 8 2 Output Format 17 24 8 2 1 NMEA Messages 17 8 2 1 1 GPGLL Geographic position Lat Lon 17 ...

Page 3: ...31 32 9 1 NMEA Configuration Query PRTHQ UxOP 31 9 2 NMEA Configuration Set PRTHS UxOP 31 9 3 UART Configuration Query PRTHQ UxCM 32 9 4 UART Configuration Set PRTHQ UxCM 32 10 LED INTERFACE 32 11 ILD NETWORK ASSIST MESSAGE FORMAT 33 39 11 1 Message Definitions 34 39 11 1 1 EPH Ephemeris Sub frame Message 34 11 1 2 ALM Almanac Subframe Message 34 11 1 3 KLB Klobuchar Ionospheric Parameters Message...

Page 4: ...nable better sensitivity but also makes for very rapid acquisition of the satellites At outdoor signal levels the time taken to obtain a hot position fix is under 2 seconds With a size of just over an inch square 25 x 27 mm the CW25 is specifically designed to be integrated with communi cations devices such as GSM CDMA UMTS modems or any other communications medium The CW25 is also optimised for t...

Page 5: ...lowance for this must be made when using the solution To measure the range from the satellite to the receiver two criteria are required signal transmission time and signal reception time All GPS satellites have several atomic clocks that keep precise time and these are used to time tag the message i e code the transmission time onto the signal and to control the transmission sequence of the coded ...

Page 6: ...h other For example a high TDOP will cause receiver clock errors that will eventually result in increased position errors Horizontal accuracy figure of 95 is the equivalent to 2RMS twice root mean square or twice the standard deviation radial error Similarly for vertical and time errors a figure of 95 is the value of 2 standard deviations of vertical or time error Root mean square RMS error is the...

Page 7: ...rent 10mA RF3V3 DIG3V3 Standby Current VBATT 1 5µA Interfaces Serial 3 UART ports CMOS levels Multi function I O 1PPS Frequency Output available on GPIO 0 Event Counter Timer Input Up to 4 x GPIO multi function 2 x LED Status Drive I2 C External Clock on special build Protocols Network Assist NMEA 0183 Proprietary ASCII and binary message formats 1pps Timing Output 30ns rms accuracy 5ns resolution...

Page 8: ... Emulation Comms I O RF25IC BB25IC 2 4 Block Diagram 2 3 Absolute Maximum Ratings Symbol Parameter Min Max Units RF_3V3 RF Supply Voltage 0 3 6 5 Volts DIG_1V8 Digital Supply Voltage 0 3 2 0 Volts DIG_3V3 Digital Supply Voltage 0 3 3 7 Volts VBATT Battery Backup Voltage 0 5 7 0 Volts ANT_SUPPLY Antenna Supply Voltage 15 15 Volts DIG_SIG_IN Any Digital Input Signal 0 3 5 5 Volts RF_IN RF Input 15 1...

Page 9: ...ails The interface to the CW25 is via 1mm castellation on a 2mm pitch There are 42 connections in all There is also an RF connector for connecting to the GPS antenna The details of the interface connections are given below Pin Function Pin Function 1 TX 0 22 TMS 2 RX 0 23 RF_GND 3 TX 2 24 RF_IN 4 RX 2 EV2_IN 25 RF_GND 5 TX 1 26 ANT_SUPPLY 6 RX 1 27 VBATT 7 EXT_CLK 28 N2WCK 8 LED_RED 29 N2WDA 9 LED...

Page 10: ...the radius of the castellation The castellations are gold plated and so are lead free Note that if the RF_IN connector is being used there should not be a pad or solder resist under the RF_IN castellation If the RF_IN castellation is to be used the pad should be shortened by 0 5mm underneath the CW25 and standard RF design practices must be observed The diagram below shows the placement of the pad...

Page 11: ... 3 3V 10 input supplies the I O ring of the BB25IC chip and the LDO regulator in the digital section of the CW25 It is important that this supply is well filtered with no more that 50mV peak to peak noise with respect to DIG_GND DIG_1V8 Type Power Direction Input Pin 34 The 1 8V 5 digital core supply for the BB25IC This is normally connected directly to the 1V8_OUT signal However if an external 1 ...

Page 12: ...al This is the standard JTAG test data input The signal return path is DIG_GND TDO Type Test Direction Output Pin 13 The Test Data Out signal This is the standard JTAG test data output The signal return path is DIG_GND TCK Type Test Direction Input Pin 20 The Test Clock signal This is the standard JTAG test clock input The signal return path is DIG_GND TMS Type Test Direction Input Pin 22 The Test...

Page 13: ...ignal The signal return path is DIG_GND TX 1 Type I O Direction Output Pin 5 The transmit signal for UART 2 This is a standard UART output signal The signal return path is DIG_GND TX 2 Type I O Direction Output Pin 3 The transmit signal for UART 3 This is a standard UART output signal The signal return path is DIG_GND RX 0 Type I O Direction Input Pin 2 The receive signal for UART 1 This is a stan...

Page 14: ... Direction Output Pin 9 This is a dual function signal Normally this signal is used to drive a green LED Standard software builds use this signal to indicate GPS status In special software builds this signal can be used as GPIO This signal has a 3 3V CMOS drive A series limiting resistor is required to limit output current to 5mA typically 270 ohms The signal return path is DIG_GND GPIO 0 PWM Type...

Page 15: ...al navigation version of the CW25 GPS Receiver It includes Network Assistance which al lows the receiver to be sent ephemeris data from a base station such as the CW55 over a communications link which allow the receiver to acquire initial positional lock in harsh environments down to signal levels of 185dBW 155dBm CW25 TIM This version of the CW25 has position hold software included which allows f...

Page 16: ...to provide either an additional PPS out put or a time synchronization input to the GPS engine GPIO 2 NEXT_INT can provide an interrupt event from an active low external input GPIO 3 FREQ_IN provide a frequency counter input Care must be taken to ensure that the pins have external bias resistors off board to ensure they are not left floating It is recommended that all unterminated test Control and ...

Page 17: ...mnemonic codes and the 5th character being selected by that manufacturer for the particular sentence structure Proprietary sentences must conform to the general NMEA structures but are otherwise undefined out side of the Manufacturers own documentation The following Approved messages are available from the CW25 receiver GPGLL Geographic Position Latitude longitude GPGGA Global Positioning System F...

Page 18: ... satellites used in the position solution HDOP 2 D Horizontal Dilution of Precision 0 00 to 99 99 AltRef Altitude metres above user datum ellipsoid M Units of height metres msl Mean Sea Level M Units of Mean Sea Level meters DiffAge Age of differential correction DiffStation Differential base station ID cs Message checksum in hexadecimal 8 2 1 3 GPGSA GPS DOP and Active satellites GPS receiver ope...

Page 19: ...ees cno Satellite signal Noise ration dB Hz cs Message checksum in hexadecimal 8 2 1 5 GPRMC Recommended Minimum data The Recommended Minimum sentence is defined by NMEA for GPS Transit system data GPRMC hhmmss sss status latitude N Hemisphere longitude E spd cmg ddmmyy mv mvd Mode cs Name Description GPRMC NMEA sentence header Recommended Minimum Sentence hhmmss sss UTC Time in hours minutes seco...

Page 20: ...is reduced to 2 decimal places GPZDA hhmmss sss dd mm yyyy Int Unsigned cs Name Description GPZDA NMEA sentence header Time and Date hhmmss sss UTC Time in hours minutes seconds dd UTC day mm UTC month yyyy UTC year Int Unsigned Local zone hours Int Unsigned Local zone minutes kph Speed over ground kph K Kilometers per hour fixed field cs Message checksum in hexadecimal Proprietary NMEA Messages 8...

Page 21: ...ifferential 2D solution D3 Differential 3D solution Hacc Horizontal 2 sigma accuracy estimates 0 to 99999 meters Vacc Vertical 2 sigma accuracy estimates 0 to 99999 meters SOG Speed Over Ground knots 0 000 to 999 999 knots COG Course Over Ground true in degrees 0 00 to 359 99 degrees V_vel Vertical positive Up velocity m s 0 000 to 999 999 m s ageC Age of most recent DGPS Corrections applied secon...

Page 22: ... Note More than one efield or ifield may be present each separated by commas Name Description POLYI Navsync Proprietary NMEA sentence header Additional Information JN Fixed descriptor field jammer Detected Jammer to Noise Ratio dB Hz EXT Fixed descriptor field indicates the use of externally provided ancillary measurements e g received from Network Assistance All comma separated fields following u...

Page 23: ... 4141 208 72 120 0 168 10 0 032 10 1 1171 99 4 6 3 SV 16 63 101B 6 30 0 273 x 9 0 0 000 00 0 000 00 0 1178 99 106 3945 7 THE_END 42 HC 0 0 0 2 EEPROM read 0x0000 0 EEPROM write e e e e e ea H 0x0000 0 8 2 2 Debug Messages The debug messages were implemented for internal testing purposes but may be useful for advanced users requiring more information than is available through the standard NMEA outp...

Page 24: ...number set flag Time set flag Sufficient position flag Skip check flag Time to first fix Time to first fix ION definition Satellite Information Satellite ID Tracking status not described Measurement status Signal strength C No Mean signal strength Lock counter IODE Elevation angle Satellite used in solution flag Pseudorange residuals Pseudorange re siduals OK flag Pseudorange residuals edit flag D...

Page 25: ...f are the ASCII codes 0Dh and 0Ah carriage return and line feed respectively Some commands use multiple sentences to transfer data multiple sentence transfer shall be accomplished by means of 2 fields within the sentence for which this format is used t Total number of sentences forming the data transfer minimum value 1 x ID number of the current sentence ranging from 1 to t inclusive Null fields w...

Page 26: ...nput options are available one allowing a calendar date and GMT time to be input and the other a GPS week number and seconds of week The input date is acted upon regardless and is primarily used to set the GPS week inside the receiver The time input will not be used if is set to zero or if the receiver is currently tracking any satellites and therefore already has a good sub millisecond knowledge ...

Page 27: ...phemeris data stored in EEPROM ALM clear the satellite almanac data stored in EEPROM NA clear the network assist data stored in EEPROM 8 3 5 PRTH Q S R INTM INTERMITTENT OPERATION PARAMETERS Purpose This message Queries Sets and Respond with the Fix Interval Run Duration Run Interval Horizontal and Vertical Accuracy Masks for intermittent operation Once the receiver has met the required Horizontal...

Page 28: ...in metres floating point range 18 000 0 AntHt Height of the antenna phase centre above the reference marker height defined by EllHt above in metres floating point range 18 000 0 posRMS RMS accuracy of the input position metres floating point range 0 999999 0 Note that since the Degree Minutes and Seconds fields will accept floating point values then a decimal degree value or and integer degree dec...

Page 29: ...sum cr lf Explanation of Parameters min_NSV Minimum Satellites used for a position time solution integer range 0 12 max_NSV Maximum Satellites used for a position time solution integer range 0 12 8 3 10 PRTH Q S R DRLM DEAD RECKONING LIMIT Purpose This message Sets Queries and Responds to the limit for the forward predictive Dead Reckoning after the last valid fix epochs The dead reckoning will pr...

Page 30: ...sponse Provide GPS Almanac message TIA EIA IS 801 section 4 2 4 2 page 4 41 Base Station response Provide GPS Ephemeris message TIA EIA IS 801 section 4 2 4 2 page 4 44 The messages should be sent out in the order Provide Location Response Provide GPS Almanac and Provide GPS Ephemeris The messages are variable length and flags within the messages identify the inclusion or exclusion of various sub ...

Page 31: ...fied is applied to all sentences An example of this is shown below where every message output on port1 will be printed at a 5 second period with the exception of the GPRMC sentence which will be output every second and the POLYT sentence which will be disabled PRTHS U1OP ALL 5 RMC 1 PLT 0 An example response string is shown below In this example all sentences are output every second except GPGSV w...

Page 32: ...8400 38400 N 1 represents the port Tx baud rate Rx baud rate parity and stop bits respectively A NMEA checksum of the form 4D is appended to the output string Although the format of the command supports the use of different Rx and Tx baud rates this is not currently supported by the CW25 platform Consequently the Rx and Tx baud rates returned will always be identical 9 4 UART Configuration Set PRT...

Page 33: ...ed as closely as possible to it These are also very close to the data structures that are used at the NS3K and XG4K API interfaces and hence minimizes the data manipulation in the user application code outside the GPS_Core API interface CW25 Dev Kit CW55 Network Assist Base Station Port 1 Port 2 Port 3 Port 4 Port 1 Port 2 Port 3 Port 4 NMEA Data Outdoor Antenna CW25 Antenna Figure 6 Network Assis...

Page 34: ...Description EPH GPS Navigation Message Ephemeris data for a single satellite See ICD GPS 200 for full details SV SV id number for the ephemeris data to follow W i i 1 to 24 24 words of the Ephemeris subframes data from words 3 to 10 of subframes 1 2 and 3 of the GPS Navigation Message Each of the raw 30 bit data words have been logically shifted 6 bits to the right to remove the 6 parity bits leav...

Page 35: ...r semicircle3 b0 b0 x 211 seconds b1 b1 x 214 seconds per semicircle b2 b2 x 216 seconds per semicircle2 b3 b3 x 216 seconds per semicircle3 cs 8 bit accumulative checksum of all bytes in between the and characters in hexadecimal 11 1 4 UCP UTC Correction Parameters Message This message is output approximately once every 16 seconds UCP A1 A0 Tot WNt dtLS WNLSF DN dtLSF cs UCP 20 8 15 3 13 222 5 13...

Page 36: ...s message is output every seconds and provides an estimate of the user s location along with an uncertainty for this estimate This message has not currently been implemented In many Network Assistance applications the location provided will be the position of the Base Station itself and the un certainty will be sufficiently large to cover all possible positions that a user able to communicate with...

Page 37: ...A10D92 C0E3E9 AF2AD0 280C02 2D014F 72 WTP 1282 467133 123 3912410 78918 5020022 C9 EPH 06 409001 191EA0 D180AF B1A11B D70FF5 4B7242 000145 2C7A40 4B084E 38258E 0A93F7 068403 6813BB 1294A1 0E1379 72427F 0059C5 DCF2CA FFE026 199E24 1831AF 1F3454 FFA567 4B0CA5 41 ALM 07 1283 476B8C 0FFC42 FD4500 A10C34 BFC27E B5493D 7DE84A 36FF7D DA ALM 08 1283 484AA1 0F0F3E FD5700 A10C85 6DEFF7 630BEA 2ECA8F FF0004 ...

Page 38: ... 1282 467142 339 3912413 78916 5020027 D8 EPH 20 409001 191EA0 D180AF B1A11B D70FF1 8D7242 000020 EE3A42 8DFC4E 302338 979E6A FC5901 34559B 118BA1 0CDA02 72427D FFE51B D9E55F FFEF27 4328C4 1B5441 D2650C FFA85E 8DF4D2 DE ALM 26 1283 5A7FAC 0F1A1E FD6300 A10D2F 425700 196253 685883 18008E 46 ALM 27 1283 5B95C2 0F0530 FD4900 A10D44 6A373F A8A532 FC1029 2E00B3 55 WTP 1282 467143 363 3912414 78915 5020...

Page 39: ...4B18FE 90E825 FD1400 A10CF2 ED07E2 02BFAA 7EA606 12002A 86 WTP 1282 467150 531 3912417 78914 5020030 CD EPH 04 409000 191EA0 D180AF B1A11B D70FF3 DA7242 00FF7E E0784B DA00CE 36AD6B 133310 00EC03 65D59D 098BA1 0D9E63 72424C FF97F2 66D059 002327 10BCB9 2490FD AD84C2 FFA4B2 DAFBFE 04 ALM 13 1283 4D1370 0F1B34 FD6400 A10CA5 423D1E 25448B AD34F8 FC001B 68 ALM 14 1283 4E0AB1 0F1791 FD5D00 A10CB3 41D87B ...

Page 40: ...ed the UTC GPS separation parameter downloaded from the satellite this may take up to 12 5 minutes from a cold start 13 Frequency Output The CW25 is capable of producing a user select frequency The frequency is output on GPIO 0 port pin 39 The frequency is configured using the FRQD command as detailed in section 8 3 10 The frequency is only valid when the receiver has a valid 2D position fix or be...

Page 41: ...n board linear regulator If the source impedance of the power supply to the CW25 is high due to long tracks filtering or other causes local decoupling of the supply signals may be necessary Care should be taken to ensure that the maximum supply ripple at the pins of the CW25 is 50mV peak to peak 14 2 RF Connection The RF connection to the CW25 can be done in two ways The preferred method is to use...

Page 42: ...25 with a ground plane 14 4 Battery Backup The CW25 has an on board real time clock RTC This is used to store date and time information whilst the CW25 is pow ered down Having a valid date and time speeds the time to first fix TTFF allowing the CW25 to meet its quoted TTFF specification The CW25 relies on an external power source to power the RTC VBATT when the DIG_3V3 is not present If the user a...

Page 43: ...ed low the CW25 boots from the ROM internal to the NS3000IC This ROM has a boot loader that polls the serial ports and I2 C bus for boot code This mode of operation requires special user handling and should only be used in conjunction with specific applica tion notes 14 7 1 Flash Programming The CW25 contains 128k Flash memory internal to the BB25IC which hold the module firmware The Flash is repr...

Page 44: ...on of a map or chart Usually chosen for a best fit over the area of interest and thus the Datum for various parts of the world may differ Delta range Small changes in range between a satellite and the receiving antenna DoD American Department of Defence DOS Disk Operating System DOP A DOP Dilution of Position is a figure which represents the purely geometrical contribution of the satellites positi...

Page 45: ...le per hour L1 The 1575 42 MHz frequency radiated by GPS satellites L band The band of radio frequencies between 1 and 2 GHz Lithium A metallic element used in batteries LMT Local Mean Time mA Milliamp of current Macro Text containing frequently used operations which can be executed as a single command DM only MHz Megahertz i e one million cycles per second mph Miles per Hour MSL Mean Sea Level ge...

Page 46: ...ces RTC Real time Clock maintaining approximate time when unit is off RTK Real Time Kinematic RTS Request to Send serial communication handshaking RXD Receive Data serial communication to Data Terminal or DTE from Data Communication Equipment or DCE S A Selective Availability imposed by the DoD to limit the GPS performance available to civil users SEP Spherical Error Probability SMA Miniature thre...

Page 47: ...ion There are several GPS related sites on the World Wide Web www that are excellent sources to obtain further information about GPS and the current status of the satellites U S Coast Guard Navigation Center Civilian GPS service notices general system information and GPS outage reporting www navcen uscg gov U S Naval Observatory General USNO information and links to USNO timing and other useful si...

Page 48: ...sprocket holes is 0 20 III Measured from center line of sprocket hole to center line of pocket IV Other material available ALL DIMENSIONS IN MILLIMETERS UNLESS OTHERWISE STATED General Tolerance 0 2 Drawing not to Scale Solder Profile 0 50 100 150 200 250 300 0 50 100 150 200 250 300 350 Time sec Temp C 221 C Reflow Zone 30 90 sec Min Max Peak Temp 245 255 C for 15 sec Typ Soaking Zone 60 90 sec T...

Page 49: ...Copyright 2007 NavSync Ltd All Rights Reserved Specifications subject to change without notice CW25 Software User Manual Page 49 of 50 Rev 03 Date 06 16 08 ...

Page 50: ...urora IL 60505 USA Phone 630 236 3026 E mail northamerica navsync com www navsync com Revision Revision Date Notes P 0 1 01 24 07 Preliminary User Manual P 0 2 05 03 07 Updated to new Format V1 0 08 26 07 Updated to Released Version V1 03 11 07 07 Revisions and Edits Update R02 04 21 08 Data Updates Update to new Revision System R03 06 16 08 Data Revisions to Section 8 dBW to dBm ...