L80 GPS Protocol Specification GPS Module Series Rev. L80_GPS_Protocol_Specification_V1.0 Date: 2013-07-09 www.quectel.
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GPS Module L80 GPS Protocol Specification About the document History Revision 1.
GPS Module L80 GPS Protocol Specification Contents About the document ................................................................................................................................... 2 Contents ....................................................................................................................................................... 3 Table Index ....................................................................................................................................
GPS Module L80 GPS Protocol Specification 3.28. 3.29. 3.30. 3.31. 4 5 Packet Type: 513 PMTK_DT_SBAS_ENABLED...................................................................... 35 Packet Type: 514 PMTK_DT_NMEA_OUTPUT ....................................................................... 36 Packet Type: 705 PMTK_DT_RELEASE.................................................................................. 37 Packet Type: 869 PMTK_EASY_ENABLE .................................................................
GPS Module L80 GPS Protocol Specification Table Index TABLE 1: STRUCTURE OF NMEA MESSAGE .................................................................................................. 7 TABLE 2: STRUCTURE OF MTK NMEA PACKET ........................................................................................... 16 TABLE 3: RELATED DOCUMENTS .................................................................................................................. 39 TABLE 4: TERMS AND ABBREVIATIONS ..........
GPS Module L80 GPS Protocol Specification 1 Introduction L80 is a full featured GPS module with super sensitivity. It is characteristic of low power consumption and compact size. The module supports autonomous GPS C/A, SBAS function (including WAAS and EGNOS) and AGPS (EASY function). It can be used in the positioning, navigation and other industries. l e t l c a i e t u n Q fide n o C This document describes the software aspects of L80. L80 supports NMEA 0183 standard commands.
GPS Module L80 GPS Protocol Specification 2 Standard NMEA Packet Protocol L80 supports NMEA 0183 standard messages. The following table shows the structure of a NMEA 0183 standard message. l e t l c a i e t u n Q fide n o C Table 1: Structure of NMEA message Filed $ Talker ID NMEA message ID Data Field * Checksum NOTE Length(bytes) Description 1 Each NMEA message starts with ‘$’ 1~2 ‘GP’ for a GPS receiver.
GPS Module L80 GPS Protocol Specification $ Each NMEA message starts with ‘$’ GPRMC Message ID UTC time Time in format ‘hhmmss.sss’ Data valid ‘V’ =Invalid ‘A’ = Valid Latitude Latitude in format ‘ddmm.mmmm’ (degree and minutes) N/S ‘N’ = North ‘S’ = South Longitude E/W Speed COG Date l e t l c a i e t u n Q fide n o C Longitude in format ‘dddmm.
GPS Module L80 GPS Protocol Specification $ Each NMEA message starts with ‘$’ GPVTG Message ID COG(T) Course over ground (true) in degree T Fixed field, true COG(M) Course over ground (magnetic), not being output M Fixed field, magnetic Speed N Speed k l e t l c a i e t u n Q fide n o C Speed over ground in knots Fixed field, knots Speed over ground in km/h Fixed field, km/h Positioning mode ‘N’ = No fix ‘A’ = Autonomous GNSS fix ‘D’ = Differential GNSS fix * End character of data field
GPS Module L80 GPS Protocol Specification Data valid ‘V’ =Invalid ‘A’ = Valid Latitude Latitude in format ‘ddmm.mmmm’ (degree and minutes) N/S ‘N’ = North ‘S’ = South Longitude Longitude in format ‘dddmm.
GPS Module L80 GPS Protocol Specification $ Each NMEA message starts with ‘$’ GPGSA Message ID Mode Auto selection of 2D or 3D fix ‘M’ = Manual, forced to switch 2D/3D mode ‘A’ = Allowed to automatically switch 2D/3D mode Fix status ‘1’ = No fix ‘2’ = 2D fix ‘3’ = 3D fix Satellite used 1 Satellite used on channel 1 Satellite used 2 Satellite used on channel 2 Satellite used 3 Satellite used on channel 3 Satellite used 4 Satellite used on channel 4 Satellite used 5 Satellite used on channel
GPS Module L80 GPS Protocol Specification 2.5. GPGSV GSV, GNSS Satellites in View. One GSV sentence can only provide data for at most 4 satellites, so several sentences might be required for the full information. Since GSV includes satellites that are not used as part of the solution, GSV sentence contains more satellites than GGA does.
GPS Module L80 GPS Protocol Specification Elevation 4 Elevation in degree (0 ~ 90) Azimuth 4 Azimuth in degree (0 ~ 359) SNR 4 Signal to Noise Ration in dBHz (0 ~ 99), empty if not tracking * End character of data field Checksum Hexadecimal checksum Each of message l e t l c a i e t u n Q fide n o C 2.6. GPGLL GLL, Geographic Latitude and Longitude, contains position information, time of position fix and status. Example: $GPGLL,3110.2908,N,12123.2348,E,041139.
GPS Module L80 GPS Protocol Specification Each of message l e t l c a i e t u n Q fide n o C L80_GPS_Protocol_Specification Confidential / Released 14 / 41
GPS Module L80 GPS Protocol Specification 2.7. GPTXT This message is used to ouput information. Example: $GPTXT,01,01,02,ANTSTATUS=OK*3B Field $ GPTXT XX YY ZZ Description l e t l c a i e t u n Q fide n o C Each NMEA message starts with ‘$’ Message ID Total number of messages in this transmission. (01~99) Message number in this transmission.
GPS Module L80 GPS Protocol Specification 3 MTK NMEA Packet Protocol This chapter introduces the MTK NMEA packet protocol, which is a set of extension messages of the standard NMEA packet protocol. These messages are used to control and configure L80 GPS module. The following table shows the structure of a MTK NMEA packet.
GPS Module L80 GPS Protocol Specification PMTK MTK proprietary message Packet type 010 Message System message ‘0’ = unknown ‘1’ = startup ‘2’ = notification for the host aiding EPO ‘3’ = notification for the transition to normal mode is successfully done * End character of data field Checksum l e t l c a i e t u n Q fide n o C Hexadecimal checksum Each of message 3.2. Packet Type: 011 PMTK_TXT_MSG This message is used to automatically output system messages by GPS module.
GPS Module L80 GPS Protocol Specification 3.3. Packet Type: 001 PMTK_ACK Acknowledgement of PMTK command. In order to inform the sender whether the receiver has received the packet, an acknowledge packet PMTK_ACK should return after the receiver receives a packet. Some commands will cause the GPS module to restart or change the baud rate.There is no PMTK_ACK for those commands as listed below.
GPS Module L80 GPS Protocol Specification Example: $PMTK101*32 Field Description $ Each NMEA message starts with ‘$’ PMTK MTK proprietary message Packet type 101 * End character of data field Checksum l e t l c a i e t u n Q fide n o C Hexadecimal checksum Each of message 3.5. Packet Type: 102 PMTK_CMD_WARM_START This message is used to warm start the GPS module.
GPS Module L80 GPS Protocol Specification 3.6. Packet Type: 103 PMTK_CMD_COLD_START This message is used to cold start the GPS module. Using this message will force the GPS cold restarted without using any prior location information, including time, position, almanacs and ephemeris data.
GPS Module L80 GPS Protocol Specification Each of message 3.8. Packet Type: 161 PMTK_CMD_STANDBY_MODE This message is used to enter standby mode for power saving. Example: $PMTK161,0*28 Field $ PMTK Packet type type * Checksum l e t l c a i e t u n Q fide n o C Description Each NMEA message starts with ‘$’ MTK proprietary message 161 ‘0’=Stop mode End character of data field Hexadecimal checksum Each of message 3.9.
GPS Module L80 GPS Protocol Specification Checksum Hexadecimal checksum Each of message Return: Example: $PMTKLOG,456,0,11,31,2,0,0,0,3769,46*48 Field $ PMTK Packet type Serial# Type Mode Content Interval Distance Speed Status Number Percent * Checksum Description l e t l c a i e t u n Q fide n o C Each NMEA message starts with ‘$’ MTK proprietary message LOG Logging serial number: 0~65535 Logging type-0: Overlap, 1:Fullstop Logging mode-0x08: Interval logger Logging cont
GPS Module L80 GPS Protocol Specification 3.10. Packet Type: 184 PMTK_LOCUS_ERASE_FLASH This message is used to erase logger flash. Example: $PMTK184,1*22 Field Description $ Each NMEA message starts with ‘$’ PMTK Packet type type * Checksum l e t l c a i e t u n Q fide n o C MTK proprietary message 184 ‘1’=Erase all logger internal flash data End character of data field Hexadecimal checksum Each of message 3.11.
GPS Module L80 GPS Protocol Specification 3.12. Packet Type: 622 PMTK_Q_LOCUS_DATA This message is used to dump locus flash data. Example: $PMTK622,1*29 Field Description $ Each NMEA message starts with ‘$’ PMTK Packet type type * Checksum l e t l c a i e t u n Q fide n o C MTK proprietary message 622 ‘1’=dump partial in used flash data End character of data field Hexadecimal checksum Each of message 3.13.
GPS Module L80 GPS Protocol Specification run time ‘0’:Disable >=’1000’:Enable (Range: 1000~518400000) sleep time (Range:1000~518400000) Second run time ‘0’:Disable >=’1000’:Enable (Range: 1000~518400000) Second sleep time (Range:1000~518400000) * End character of data field Checksum Hexadecimal checksum NOTE l e t l c a i e t u n Q fide n o C Each of message The unit of run time or sleep time is msec, the second run time should larger than first run time when non-zero value. 3.14.
GPS Module L80 GPS Protocol Specification 19200 38400 57600 115200 * End character of data field Checksum Hexadecimal checksum Each of message l e t l c a i e t u n Q fide n o C 3.15. Packet Type: 286 PMTK_SET_AIC _ENABLED This message is used to enable or disable AIC function. It is suggested to set cold start command first and then PMTK command.
GPS Module L80 GPS Protocol Specification Field Description $ Each NMEA message starts with ‘$’ PMTK MTK proprietary message Packet type 300 Fix interval Position fix interval [msec]. Must be greater than 100. Reserved 0 Reserved Reserved Reserved * Checksum l e t l c a i e t u n Q fide n o C 0 0 0 End character of data field Hexadecimal checksum Each of message 3.17. Packet Type: 301 PMTK_API_SET_DGPS_MODE This message is used to configure the source mode of DGPS correction data.
GPS Module L80 GPS Protocol Specification Each of message 3.18. Packet Type: 313 PMTK_API_SET_SBAS_ENABLED This message is used to enable or disable to search a SBAS satellite. SBAS (Satellite Based Augmentation Systems) is a system that supports wide-area or regional augmentation through geostationary satellite broadcast messages.
GPS Module L80 GPS Protocol Specification 5 - Output once every five position fixes Example: $PMTK314,1,1,1,1,1,5,0,0,0,0,0,0,0,0,0,0,0,1,0*2D Field Description $ Each NMEA message starts with ‘$’ PMTK MTK proprietary message Packet type 314 0 GLL 1 RMC 2 VTG 3 GGA 4 GSA 5 GSV 6 Reserved 7 Reserved 8 Reserved 9 Reserved 10 Reserved 11 Reserved 12 Reserved 13 Reserved 14 Reserved l e t l c a i e t u n Q fide n o C GLL interval - Geographic Position - Latitude longitude RMC interval - Recom
GPS Module L80 GPS Protocol Specification * End character of data field Checksum Hexadecimal checksum Each of message To restore the system default setting, use below message: Example: $PMTK314,-1*04 Field $ PMTK Packet type Restore * Checksum l e t l c a i e t u n Q fide n o C Description Each NMEA message starts with ‘$’ MTK proprietary message 314 Always -1 End character of data field Hexadecimal checksum Each of message 3.20.
GPS Module L80 GPS Protocol Specification Speed_threshold 0~2m/s * End character of data field Checksum Hexadecimal checksum Each of message 3.21. Packet Type: 400 PMTK_API_Q_FIX_CTL l e t l c a i e t u n Q fide n o C This message is used to query the rate of position fixing activity. Refer to PMTK_API_SET_FIX_CTL for setting the rate.
GPS Module L80 GPS Protocol Specification Field Description $ Each NMEA message starts with ‘$’ PMTK MTK proprietary message Packet type 401 * End character of data field Checksum Hexadecimal checksum l e t l c a i e t u n Q fide n o C Each of message 3.23. Packet Type: 413 PMTK_API_Q_SBAS_ENABLED This message is used to query the setting of SBAS. Refer to PMTK_API_SET_SBAS_ENABLE for SBAS setting. Refer to PMTK_DT_SBAS_ENABLED for the result of the query.
GPS Module L80 GPS Protocol Specification 3.24. Packet Type: 414 PMTK_API_Q_NMEA_OUTPUT This message is used to query the current NMEA sentence output frequencies. Refer to PMTK_API_SET_NMEA_OUTPUT for the frequencies setting. Refer to PMTK_DT_NMEA_OUTPUT for the result of the query.
GPS Module L80 GPS Protocol Specification Checksum Hexadecimal checksum Each of message 3.26. Packet Type: 500 PMTK_DT_FIX_CTL This message is the response to PMTK_API_Q_FIX_CTL. l e t l c a i e t u n Q fide n o C Example: $PMTK500,1000,0,0,0,0*1A Field $ PMTK Packet type Fix interval Reserved Reserved Reserved Reserved * Checksum Description Each NMEA message starts with ‘$’ MTK proprietary message 500 Position fix interval [msec]. Greater than 100.
GPS Module L80 GPS Protocol Specification Field Description $ Each NMEA message starts with ‘$’ PMTK MTK proprietary message Packet type 501 Mode DGPS data source mode. ‘0’ = No DGPS source ‘2’ = WAAS * Checksum l e t l c a i e t u n Q fide n o C End character of data field Hexadecimal checksum Each of message 3.28. Packet Type: 513 PMTK_DT_SBAS_ENABLED This message is the response to PMTK_API_Q_SBAS_ENABLED.
GPS Module L80 GPS Protocol Specification 3.29. Packet Type: 514 PMTK_DT_NMEA_OUTPUT This message is the response to PMTK_API_Q_NMEA_OUTPUT.
GPS Module L80 GPS Protocol Specification 17 ZDA ZDA interval – Time and Date 18 Reserved Always 0 * End character of data field Checksum Hexadecimal checksum Each of message l e t l c a i e t u n Q fide n o C 3.30. Packet Type: 705 PMTK_DT_RELEASE This message is the response to PMTK_Q_RELEASE. Example: $PMTK705,AXN_3.
GPS Module L80 GPS Protocol Specification 3.31. Packet Type: 869 PMTK_EASY_ENABLE This message is used to enable or disable EASY function, and it also can be used to query if EASY is enabled or disabled.
GPS Module L80 GPS Protocol Specification 4 Appendix A Reference Table 3: Related Documents SN [1] [2] [3] Document name Remark L80_Hardware_Design L80 Hardware Design L80_EVB_User Guide L80 EVB User Guide L80_Reference_Design L80 Reference Design l e t l c a i e t u n Q fide n o C Table 4: Terms and Abbreviations Abbreviation Description GPS Global Navigation Satellite System NMEA PMTK GGA RMC GSA GSV GLL VTG National Marine Electronics Association Private protocol of MTK NMEA: Global Po
GPS Module L80 GPS Protocol Specification AIC Active Interference Cancellation PDOP Position Dilution Of Precision VDOP Vertical Dilution Of Precision HDOP Horizontal Dilution Of Precision WAAS Wide Area Augmentation System PPS Pulse Per Second UTC l e t l c a i e t u n Q fide n o C Universal Time Coordinated L80_GPS_Protocol_Specification Confidential / Released 40 / 41
GPS Module L80 GPS Protocol Specification 5 Default Configurations Table 5: Default Configurations Item l e t l c a i e t u n Q fide n o C Default NMEA port baud rate 9600bps Datum WGS84 Rate of position fixing 1HZ DGPS mode SBAS SBAS enable Enable NMEA output messages GGA,RMC, GSA, GSV,VTG,GLL and GPTXT AIC On EASY L80_GPS_Protocol_Specification On Confidential / Released 41 / 41
