GPS Engine Board EM-408
Contents
1. 4800 bps 57 600bps adjustable Output Message NMEA 0183 GGA GSA GSV RMC VTG GLL optional Specifications are subject to be changed without notice are subject to be changed without notice Page 2 of 14 VA GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 Sensitivity 159dBm Cold Start 42 seconds average Warm Start 38 seconds average Hot Start Reacquisition 0 1 second average Accuracy Position 10 meters 2D RMS 5 meters 2D RMS WAAS enabled Velocity 0 1 ms Time 1us synchronized to GPS time Maximum Altitude Maximum Acceleration Dimensions A x 1 4 x 0 3 36 4 x 35 4 x 8 3mm Power Consumption 44mA Continuous Mode 25mA Trickle Power Mode Environmental Range Humidity Range 5 to 95 non condensing Operation Temperature 40F to 185F 40C to 85C Specifications are subject to be changed without notice Page 3 of 14 VA GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 2 Technical Information E Physical Characteristics Specifications are subject to be changed without notice Page 4 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 a Female Cable Connector Digi Key Part No 455 1380 ND Male PCB Header Digi Key Part No 455 1805 1 ND E Pin Assignment 4 EnablefDisable EM 408 2 GND 12345 3 RX 4 TX aE E Pin Explanation ENABLE DISABLE On Off VCC DC power input This is the main DC supply for a 3 3V p2. Serial Port B an input serial only port used to receive RTCM differential corrections Differential receivers may output corrections using different communication parameters The default communication parameters for PORT B are set for 9600 Baud 8data bits 0 stop bits and no parity If a DGPS receiver is used which has different communication parameters use this command to allow the receiver decode data correctly When a valid message is received the parameters are stored in a battery backed SRAM Resulting GPS receiver using the saved Parameters for restart Format PSRF102 lt Baud gt lt DataBits gt lt StopBits gt lt Parity gt CKSUM lt CR gt lt LF gt lt baud gt 1200 2400 4800 9600 19200 38400 lt DataBits gt 8 lt StopBits gt 0 1 lt Parity gt 0 None Odd 1 Even 2 Example Set DGPS Port to be 9600 8 N 1 PSRF102 9600 8 1 0 12 Specifications are subject to be changed without notice Page 11 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 D Query Rate Control ID 103 Query standard NMEA message and or set output rate This command is used to control standard NMEA data output messages GGA GLL GSA GSV RMC and VTG Using this command message standard NMEA message is polled once or setup for periodic output In addition checksums may also be enable or disable contingent on receiving program requirements NMEA message settings are stored in a battery backed memory for each entry when the messa
3. gt lt LF gt End of message termination GSA GNSS DOP and Active Satellites Table B 5 contains the values for the following example GPGSA A 3 07 02 26 27 09 04 15 1 8 1 0 1 5 33 Table B 5 GSA Data Format Name Example Units Description Message ID GPGSA GSA protocol header Mode1 A See Table B 6 Mode2 3 See Table B 7 Satellite Used 07 Sv on Channel 1 Satellite Used 02 Sv on Channel 2 Satellite Used Sv on Channel 12 PDOP 1 8 Position dilution of Precision HDOP 1 0 Horizontal dilution of Precision Specifications are subject to be changed without notice Page 7 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 VDOP 1 5 Vertical dilution of Precision Checksum 33 lt CR gt lt LF gt End of message termination 1 Satellite used in solution Table B 6 Mode Value Description M Manual forced to operate in 2D or 3D mode A 2D automatic allowed to automatically switch 2D 3D Table B 7 Mode 2 Value Description 1 Fix Not Available 2 2D 3 3D GSV GNSS Satellites in View Table B 8 contains the values for the following example GPGSV 2 1 07 07 79 048 42 02 51 062 43 26 36 256 42 27 27 138 42 71 GPGSV 2 2 07 09 23 313 42 04 19 159 41 15 12 041 42 41 Table B 8 GSV Data Format Name Example Units Description Messa
4. receiver will restart using the saved parameters Format PSRF100 lt protocol gt lt baud gt lt DataBits gt lt StopBits gt lt Parity gt CKSUM lt CR gt lt LF gt lt protocol gt O SiRF Binary 1 NMEA 4 USER1 lt baud gt 1200 2400 4800 9600 19200 38400 lt DataBits gt 8 7 Note that SiRF protocol is only valid f8 Data bits lt StopBits gt 0 1 lt Parity gt 0 None 1 Odd 2 Even Example 1 Switch to SIRF Binary protocol at 9600 8 N 1 PSRF100 0 9600 8 1 0 0C lt CR gt lt LF gt Example 2 Switch to User1 protocol at 38400 8 N 1 PSRF100 4 38400 8 1 0 38 lt CR gt lt LF gt Checksum Field The absolute value calculated by exclusive OR the 8 data bits of each character in the Sentence between but excluding and The hexadecimal value of the most significant and least significant 4 bits of the result are converted to two ASCII characters 0 9 A F for transmission First the most significant character is transmitted lt CR gt lt LF gt Hex OD 0A B Navigation initialization 1ID 101 Parameters required for start This command is used to initialize the GPS module for a Warm start by providing real time position in X Y Z coordinates clock offset and time This action enables the GPS receiver to search for the necessary satellite signals at the correct signal parameters The newly acquired and stored satellite data will enable the receiver to acquire signals more quickly and thus g
5. west Checksum 10 lt CR gt lt LF gt End of message termination SiRF Technology Inc does not support magnetic declination All course over ground data are Geodetic WGS48 directions VTG Course Over Ground and Ground Speed GPVTG 309 62 T M 0 13 N 0 2 K 6E Table B 9 VTG Data Format Name Example Units Description Message ID GPVTG VTG protocol header Course 309 62 degrees Measured heading Reference T True Course degrees Measured heading Reference M Magnetic Speed 0 13 knots Measured horizontal speed Units N Knots Speed 0 2 Km hr Measured horizontal speed Units K Kilometers per hour Checksum 6E lt CR gt lt LF gt End of message termination Page 9 of 14 Specifications are subject to be changed without notice yy GlobalSat TECHNOLOGY CORPORATION EM 408 Varina tas E NMEA Input Command A Set Serial Port ID 100 Set PORTA parameters and protocol This command message is used to set the protocol SIRF Binary NMEA or USER1 and or the communication parameters baud data bits stop bits parity Generally this command is utilize to switch the GPS module back to SiRF Binary protocol mode where an extensive message commands are readily available In example whenever users are interested in altering navigation parameters a valid message sent and is receive by the recipient module the new parameters will be stored in battery backed SRAM and then the
6. VA GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 GPS Engine Board EM 408 Globalsat Technology Corporation USGlobalSat Inc 16F No 186 Jian Yi Road Chung Ho City Taipei Hsien 235 14740 Yorba Court Chino CA 91710 Taiwan Tel 909 597 8525 Fax 909 597 8532 Tel 886 2 8226 3799 Fax 886 2 8226 3899 oem usglobalsat com service globalsat com tw www usglobalsat com www globalsat com tw Specifications are subject to be changed without notice Page 1 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 1 Product Information E Product Part D EM 408 E Product Description The EM 408 GPS engine board is low cost but maintains high reliability and accuracy making it an ideal choice for integration with OEM ODM systems The EM 408 features an integrated patch antenna for complete implementation E Product Features SiRF Star IIl high performance GPS chipset Very high sensitivity Tracking Sensitivity 159dBm Extremely fast TTFF Time To First Fix at low signal levels Supports the NMEA 0183 data protocol Built in SuperCap to maintain system data for rapid satellite acquisition Built in patch antenna Foliage Lock for weak signal tracking Compact in size All in view 20 channel parallel processing Superior urban canyon performance WAAS EGNOS support RoHS compliant cs eT E Product Specifications Protocol Electrical Level TTL level Output Voltage Level OV 2 85V Baud Rate
7. enerate a rapid navigational solution When a valid Navigation Initialization command is receive the receiver will restart using the input parameters as a basis for satellite selection and acquisition Format PSRF101 lt X gt lt Y gt lt Z gt lt ClkOffset gt lt TimeOfWeek gt lt WeekNo gt lt chniCount gt lt ResetCfg gt CKSUM lt CR gt lt LF gt lt X gt X coordinate position INT32 Specifications are subject to be changed without notice Page 10 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 lt Y gt Y coordinate position INT32 lt Z gt Z coordinate position INT32 lt ClkOffset gt Clock offset of the receiver in Hz Use 0 for last saved value if available If this is unavailable a default value of 75000 for GSP1 95000 for GSP 1 LX is used INT32 lt TimeOf Week gt GPS Time Of Week UINT32 lt WeekNo gt GPS Week Number UINT16 Week No and Time Of Week calculation from UTC time lt chnICount gt Number of channels to use 1 12 If your CPU throughput is not high enough you could decrease needed throughput by reducing the number of active channels UBYTE lt ResetCfg gt bit mask 0x01 Data Valid warm hotstarts 1 0x02 clear ephemeris warm start 1 0x04 clear memory Cold start 1 UBYTE Example Start using known position and time PSRF101 2686700 4304200 3851624 96000 497260 921 12 3 7F C Set DGPS Port ID 102 Set PORT B parameters for DGPS input This command is used to control
8. ge ID GPGSV GSV protocol header Number of Messages 2 Range 1 to 3 Message Number 1 Range 1 to 3 Satellites in View 07 Satellite ID 07 Channel 1 Range 1 to 32 Elevation 79 degrees Channel 1 Maximum90 Azimuth 048 degrees Channel 1 True Range 0 to 35 SNR C No 42 dBHz Range 0 to 99 null when not tr Satellite ID 27 Channel 4 Range 1 to 32 Elevation 27 Degrees Channel 4 Maximum90 Azimuth 138 Degrees Channel 4 True Range 0 to 35 SNR C No 42 dBHz Range 0 to 99 null when not tr Checksum 71 lt CR gt lt LF gt End of message termination Depending on the number of satellites tracked multiple messages of GSV data may be required RMC Recommended Minimum Specific GNSS Data Table B 9 contains the values for the following example Page 8 of 14 Specifications are subject to be changed without notice yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 GPRMC 161229 487 A 3723 2475 N 12158 3416 W 0 13 309 62 120598 10 Table B 9 RMC Data Format Name Example Units Description Message ID GPRMC RMC protocol header UTC Time 161229 487 hhmmss sss Status A A data valid or V data not valid Latitude 3723 2475 ddmm mmmm N S Indicator N N north or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or W west Speed Over Ground 0 13 knots Course Over Ground 309 62 degrees True Date 120598 ddmmyy Magnetic Variation degrees E east or W
9. ge is accepted Format PSRF103 lt msg gt lt mode gt lt rate gt lt cksumEnable gt CKSUM lt CR gt lt LF gt lt msg gt 0 GGA 1 GLL 2 GSA 3 GSV 4 RMC 5 VTG lt mode gt 0 SetRate 1 Query lt rate gt Output every lt rate gt seconds off 0 max 255 lt cksumEnable gt 0 disable Checksum 1 Enable checksum for specified message Example 1 Query the GGA message with checksum enabled PSRF103 00 01 00 01 25 Example 2 Enable VTG message for a 1Hz constant output with checksum enabled PSRF103 05 00 01 01 20 Example 3 Disable VTG message PSRF103 05 00 00 01 21 E LLA Navigation initialization ID 104 Parameters required to start using Lat Lon Alt This command is used to initialize the GPS module for a Warm start providing real time position Latitude Longitude Altitude coordinates clock offset and time This action enables the GPS receiver to search for the necessary satellite signals at the correct signal parameters The newly acquired and stored satellite data will enable the receiver to acquire signals more quickly and thus generate a rapid navigational solution When a valid LLA Navigation Initialization command is receive then the receiver will restart using the input parameters as a basis for satellite selection and acquisition Format PSRF104 lt Lat gt lt Lon gt lt Alt gt lt ClkOffset gt lt TimeOfWeek gt lt WeekNo gt lt ChannelCount gt lt ResetCfg gt CKSUM lt CR gt lt LF gt lt Lat
10. gt Latitude position assumed positive north of equator and negative south of equator float possibly signed lt Lon gt Longitude position it is assumed positive east of Greenwich and negative west of Greenwich Float possibly signed lt Alt gt Altitude position float possibly signed Specifications are subject to be changed without notice Page 12 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 lt ClkOffset gt Clock Offset of the receiver in Hz use 0 for last saved value if available If this is unavailable a default value of 75000 for GSP1 95000 for GSP1 LX is used INT32 lt TimeOfWeek gt GPS Time Of Week UINT32 lt WeekNo gt GPS Week Number UINT16 lt ChannelCount gt Number of channels to use 1 12 UBYTE lt ResetCfg gt bit mask 0x01 Data Valid warm hot starts 1 0x02 clear ephemeris warm start 1 0x04 clear memory Cold start 1 UBYTE Example Start using known position and time PSRF104 37 3875111 121 97232 0 96000 237759 922 12 3 37 F Development Data On Off ID 105 Switch Development Data Messages On Off Use this command to enable development debug information if you are having trouble in attaining commands accepted Invalid commands will generate debug information that should enable the user to determine the source of the command rejection Common input rejection problems are associated to invalid checksum or parameter out of specified range Note this setting is not preserved across a
11. module reset Format PSRF105 lt debug gt CKSUM lt CR gt lt LF gt lt debug gt 0 Off 1 On Example Debug On PSRF105 1 3E Example Debug Off PSRF105 0 3F G Select Datum ID 106 Selection of datum to be used for coordinate transformations GPS receivers perform initial position and velocity calculations using an earth centered earth fixed ECEF coordinate system Results may be converted to an earth model geoid defined by the selected datum The default datum is WGS 84 World Geodetic System 1984 which provides a worldwide common grid system that may be translated into local coordinate systems or map Datum Local map Datum are a best fit to the local shape of the earth and not valid worldwide Examples Datum select TOKYO_MEAN PSRF106 178 32 Specifications are subject to be changed without notice Page 13 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 Name Example Units Description Message ID PSRF106 PSRF106 protocol header Datum 178 21 WGS84 178 Tokyo_Mean 179 Tokyo_Japan 180 Tokyo_Korea 181 Tpkyo_Okinawa Checksum 32 lt CR gt lt LF gt End of message termination Page 14 of 14 Specifications are subject to be changed without notice
12. ower module board TX This is the main transmit channel for outputting navigation and measurement data to user s navigation software or user written software RX This is the main receive channel for receiving software commands to the engine board from SiRfDemo software or from user written software NOTE When not in use this pin must be kept HIGH for operation From Vcc connect a 470 Ohm resistor in series with a 3 2v Zener diode to Ground Then connect the Rx input to Zener s cathode to pull the input HIGH GND GND provides the ground for the engine boards Be sure to connect all grounds Specifications are subject to be changed without notice Page 5 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 E Mounting Recommended mounting methods a Use industrial grade double sided foam tape Place it on the bottom side of the engine board b Arecessed cavity in your housing design with a foam pad to eliminate shifting or movement c Use provided mounting holes on the GPS engine board PCB 3 Software Commands E NMEA Output Command GGA Global Positioning System Fixed Data Table B 2 contains the values for the following example GPGGA 161229 487 3723 2475 N 12158 3416 W 1 07 1 0 9 0 M 0000 18 Table B 2 GGA Data Format Name Example Units Description Message ID GPGGA GGA protocol header UTC Time 161229 487 hhmms
13. s sss Latitude 3723 2475 ddmm mmmm N S Indicator N N north or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or W west Position Fix Indicator 1 See Table B 3 Satellites Used 07 Range 0 to 12 HDOP 1 0 Horizontal Dilution of Precision MSL Altitude 9 0 meters Units M meters Geoid Separation meters Units M meters Age of Diff Corr second Null fields when DGPS is not used Diff Ref Station ID 0000 Checksum 18 lt CR gt lt LF gt End of message termination SiRF Technology Inc does not support geoid corrections Values are WGS84 ellipsoid heights Specifications are subject to be changed without notice Page 6 of 14 yy GlobalSat TECHNOLOGY CORPORATION EM 408 Version 1 4 1 Table B 3 Position Fix Indicator Value Description 0 Fix not available or invalid 1 GPS SPS Mode fix valid 2 Differential GPS SPS Mode fix valid 3 GPS PPS Mode fix valid GLL Geographic Position Latitude Longitude Table B 4 contains the values for the following example GPGLL 3723 2475 N 12158 3416 W 161229 487 A 2C Table B 4 GLL Data Format Name Example Units Description Message ID GPGLL GLL protocol header Latitude 3723 2475 ddmm mmmm N S Indicator n N north or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or W west UTC Position 161229 487 hhmmss sss Status A A data valid or V data not valid Checksum 2C lt CR
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