quecgnss - Internal GNSS Resolver

2025-09-29

This feature provides the APIs of the built-in GNSS feature.

QuecPython modules list that support built-in GNSS:

ECX00U AA/LA series

EG91XU AA series

EC800M GA/GB/GC/GD series
EG810M GA series
EC800G GA series

BG95M1/M3 model

Example 

import quecgnss


def main():
    quecgnss.configSet(0,1)#Set the positioning constellation to GPS + Beidou.
    quecgnss.configSet(2,1)#Turn on AGPS
    quecgnss.configSet(4,1)#Turn on the backup power supply
    ret = quecgnss.init()
    if ret == 0:
        print('GNSS init ok.')
    else:
        print('GNSS init failed.')
        return -1
    data = quecgnss.read(4096)
    print(data[1].decode())

    quecgnss.gnssEnable(0)


if __name__ == '__main__':
    main()


#===================================================================================================
#Execution Result
167,169,170,,,,,,,,1.773,1.013,1.455*15
$GPGSV,2,1,8,3,23,303,34,16,32,219,28,22,74,98,26,25,16,43,25*77
$GPGSV,2,2,8,26,70,236,28,31,59,12,38,32,55,127,34,4,5,,21*49
$BDGSV,2,1,8,163,51,192,32,166,70,11,31,167,52,197,32,169,59,334,31*61
$BDGSV,2,2,8,170,40,205,31,161,5,,31,164,5,,27,165,5,,29*59
$GNRMC,022326.000,A,3149.324624,N,11706.921702,E,0.000,261.541,180222,,E,A*38
$GNGGA,022326.000,3149.324624,N,11706.921702,E,1,12,1.013,-8.580,M,0,M,,*47
$GNGLL,3149.324624,N,11706.921702,E,022326.000,A,A*44
$GNGSA,A,3,31,32,3,16,22,25,26,,,,,,1.773,1.013,1.455*1C
$GNGSA,A,3,163,166,167,169,170,,,,,,,,1.773,1.013,1.455*15
$GPGSV,2,1,8,3,23,303,34,16,32,219,27,22,74,98,26,25,16,43,25*78
$GPGSV,2,2,8,26,70,236,28,31,59,12,37,32,55,127,34,4,5,,20*47
$BDGSV,2,1,8,163,51,192,32,166,70,11,31,167,52,197,32,169,59,334,31*61
$BDGSV,2,2,8,170,40,205,31,161,5,,31,164,5,,27,165,5,,29*59
$GNRMC,022327.000,A,3149.324611,N,11706.921713,E,0.000,261.541,180222,,E,A*3F
$GNGGA,022327.000,3149.324611,N,11706.921713,E,1,12,1.013,-8.577,M,0,M,,*48
$GNGLL,3149.324611,N,11706.921713,E,022327.000,A,A*43
...... # Omit some data due to large data quantity.
$GNGSA,A,3,31,32,3,16,22,25,26,,,,,,1.837,1.120,1.456*11
$GNGSA,A,3,163,166,167,169,170,,,,,,,,1.837,1.120,1.456*18
$GPGSV,2,1,8,3,23,302,27,16,32,220,26,22,73,101,27,25,16,43,27*45
$GPGSV,2,2,8,26,70,237,28,31,59,13,33,32,54,128,28,4,5,,24*44
$BDGSV,2,1,8,163,51,192,33,166,71,11,35,167,52,198,33,169,59,334,34*6E
$BDGSV,2,2,8,170,40,205,32,161,5,,33,164,5,,28,165,5,,30*5F
$GNRMC,022507.000,A,3149.324768,N,11706.922344,E,0.000,261.541,180222,,E,A*31
$GNGGA,022507.000,3149.324768,N,11706.922344,E,1,12,1.120,-8.794,M,0,M,,*48
$GNGLL,3149.324768,N,11706.922344,E,022507.000,A,A*4D
$GNGSA,A,3,31,32,3,16,22,25,26,,,,,,1.837,1.120,1.455*12
$GNGSA,A,3,163,166,167,169,170,,,,,,,,1.837,1.120,1.455*1B
$GPGSV,2,1,8,3,23,302,26,16,32,220,26,22,73,101,27,25,16,43,26*45
$GPGSV,2,2,8,26,70,237,28,31,59,13,32,32,54,128,28,4,5,,24*45
$BDGSV,2,1,8,163,51,192,24,166,71,11,35,167,52,198,33,169,59,334,34*68
$BDGSV,2,2,8,170,40,205,31,161,5,,33,164,5,,28,165,5,,30*5C
$GNRMC,022508.000,A,3149.324754,N,11706.922338,E,0.002,261.541,180222,,E,A*38
$GNGGA,022508.000,3149.324754,N,11706.922338,E,1,12,1.120,-8.750,M,0,M,,*4B
$GNGLL,3149.324754,N,11706.922338,E,022508.000,A,A*46
$GNGSA,A,3,31,3

Overview of GNSS Positioning Data 

NMEA Port Data Classification:：
                $GPGGA Global Positioning System Fix Data
                $GPGSA GNSS DOP and Active Satellites 
                $GPGSV GNSS Satellites in View
                $GPRMC Recommended Minimum Specific GNSS Data
                $GPVTG Course Over Ground and Ground Speed 
                $GPDTM Datum Reference
                $GPGNS GNSS Fix Data
NMEA Sentence Parsing：
The basic format of the GSV sentence is as follows:

                $GPGSV,(1),(2),(3),(4),(5),(6),(7),...,(4),(5),(6),(7)*hh(CR)(LF)

                Field 1: Total number of GSV sentences.

                Field 2: Sequence number of the current GSV sentence.

                Field 3: Total number of satellites in view (00–12, leading zeros are transmitted).

                Field 4: Satellite PRN number (01–32, leading zeros are transmitted).

                Field 5: Elevation of the satellite (00–90 degrees, leading zeros are transmitted).

                Field 6: Azimuth of the satellite (000–359 degrees, leading zeros are transmitted).

                Field 7: Signal-to-noise ratio (00–99 dB; left blank if the satellite is not being tracked) — also referred to as the C/N0 value.

The basic format of the GGA sentence is as follows:

                $GPGGA,(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12)*hh(CR)(LF)

                Field 1: UTC time, hhmmss.sss (hours, minutes, seconds format).

                Field 2: Latitude ddmm.mmmm (degrees and minutes format, leading zeros transmitted).

                Field 3: Latitude hemisphere — N (North) or S (South).

                Field 4: Longitude dddmm.mmmm (degrees and minutes format, leading zeros transmitted).

                Field 5: Longitude hemisphere — E (East) or W (West).

                Field 6: GPS status — 0 = Invalid, 1 = GPS fix, 2 = DGPS fix, 3 = Invalid PPS, 6 = Estimated.

                Field 7: Number of satellites used (00–12, leading zeros transmitted).

                Field 8: HDOP (Horizontal Dilution of Precision), range 0.5–99.9.

                Field 9: Altitude (-9999.9 to 99999.9).

                Field 10: Altitude unit, meters.

                Field 11: Height of geoid (ellipsoid relative to mean sea level).

                Field 12: Height unit of geoid separation, meters.

The basic format of the GSA sentence is as follows:

                $GPGSA,(1),(2),(3),(3),,,,,,,,,,(3),(4),(5),(6),(7)*hh(CR)(LF)

                Field 1: Mode — A = Automatic 2D/3D, M = Manual 2D/3D.

                Field 2: Fix type — 1 = No fix, 2 = 2D fix, 3 = 3D fix.

                Field 3: PRN codes — Satellite PRN number(s) being used in the current fix (00; leading zeros transmitted, up to 12 satellites).

                Field 4: PDOP (Position Dilution of Precision), range 0.0–500.0.

                Field 5: HDOP (Horizontal Dilution of Precision), range 0.0–500.0.

                Field 6: VDOP (Vertical Dilution of Precision), range 0.0–500.0.

                Field 7: Satellite system ID.

The basic format of the VTG sentence is as follows:

                $GPVTG,(1),(2),(3),(4),(5),(6),(7),(8),(9)*hh(CR)(LF)

                Field 1: Course over ground (000–359, leading zeros transmitted).

                Field 2: Reference — T = True North.

                Field 3: Course over ground (000–359, leading zeros transmitted).

                Field 4: Reference — M = Magnetic North.

                Field 5: Horizontal speed (0.00, leading zeros transmitted).

                Field 6: Unit — N = Knots.

                Field 7: Horizontal speed (0.00, leading zeros transmitted).

                Field 8: Unit — K = Kilometers per hour (km/h).

                Field 9: Mode indicator — E = Estimated, A = Autonomous (non-DGPS).

The basic format of the RMC sentence is as follows:

                $GPRMC,(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12),(13)*hh(CR)(LF)

                Field 1: UTC time, hhmmss.sss format.

                Field 2: Status — A = Valid (fix), V = Invalid (no fix).

                Field 3: Latitude ddmm.mmmm (degrees and minutes format, leading zeros transmitted).

                Field 4: Latitude hemisphere — N (North) or S (South).

                Field 5: Longitude dddmm.mmmm (degrees and minutes format, leading zeros transmitted).

                Field 6: Longitude hemisphere — E (East) or W (West).

                Field 7: Speed over ground, in knots.

                Field 8: Course over ground, in degrees.

                Field 9: UTC date, DDMMYY format.

                Field 10: Magnetic variation (000–180 degrees, leading zeros transmitted).

                Field 11: Magnetic variation direction — E (East) or W (West).

                Field 12: Mode indicator — E = Estimated, A = Autonomous (non-DGPS).

                Field 13: Navigation status — V = Navigation status not provided.

The basic format of the DTM sentence is as follows:

                 $GNDTM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*<9>(CR)(LF)

                <1>Local datum code — W84, P90.

                <2>Datum subcode — blank.

                <3>Latitude offset.

                <4>Latitude hemisphere — N (North) or S (South).

                <5>Longitude offset.

                <6>Longitude hemisphere — E (East) or W (West).

                <7>Altitude offset.

                <8>Reference datum code — W84.

                <9>Checksum.

The basic format of the GNS sentence is as follows:

                $GNGNS,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>.<9>,<10>,<11>,<12>,<13>,*<14>(CR)(LF)

                <1> UTC time: Fix time hhmmss.ss — 000000.00 ~ 235959.99

                <2> Latitude: ddmm.mmmmm — 0000.00000 ~ 8959.9999

                <3> Latitude hemisphere: N = North, S = South

                <4> Longitude: dddmm.mmmmm — 0000.00000 ~ 17959.99999

                <5> Longitude hemisphere: E = East, W = West

                <6> Mode indicator: N = No fix; A = Autonomous; D = Differential; P = Precise; R = RTK Fixed; F = RTK Float; E = Estimated; M = Manual input; S = Simulator

                <7> Satellites used: Number of satellites used in fix, 00–99

                <8> HDOP: Horizontal Dilution of Precision, 0.5–99.9

                <9> Altitude: Unit = meters

                <10> Geoid separation: Height of geoid relative to WGS84 ellipsoid

                <11> Differential data age: blank if prefix is “GN”

                <12> Reference station ID: blank if prefix is “GN”

                <13> Navigation status: C = Caution, S = Safe, U = Unsafe, V = Invalid

                <14> Checksum

Initialize GNSS

quecgnss.init 

quecgnss.init()

Initializes the built-in GNSS feature.

Return Value
0 - Successful execution

-1 - Failed execution

Get GNSS Working Status

quecgnss.get_state 

quecgnss.get_state()

Gets the current working status of the built-in GNSS feature.

Return Value

Value Type Description
0 int GNSS feature is disabled.
1 int GNSS firmware is being updated.
2 int GNSS is positioning. In this mode, the module can read the GNSS location data. After obtaining the location data, the user needs to analyze the corresponding sentence to determine whether the location data is effective. For example, if the status of GNRMC sentences is A or V, A indicates valid positioning and V indicates invalid positioning.

Enable or Disable GNSS

quecgnss.gnssEnable 

quecgnss.gnssEnable(opt)

Enables or disables GNSS feature. If you use the built-in GNSS feature for the first time after powering the module on, you need not call this function to enable GNSS feature, but call quecgnss.init() directly. quecgnss.init() will automatically enable the GNSS feature when GNSS feature is initialized.

Parameter

opt - Integer type. Enable or disable GNSS.

0 - Disable the GNSS feature.

1 - Enable the GNSS feature.

Return Value

0 - Successful execution

-1 - Failed execution

Get GNSS Location Data

quecgnss.read 

quecgnss.read(size)

Gets GNSS location data.

Parameter

size - Integer type. Size of the data to be read. Unit: byte.

Return Value

A tuple (size, data) - Successful execution

size - Size of the data read.
data - GNSS location data.

-1 - Failed execution

GNSS/LTE Priority Settings

Currently, this function is only supported by BG95M1/M3 models.

quecgnss.setPriority 

quecgnss.setPriority(Priority)

On some modules, GNSS and LTE share RF resources. This interface is used to control the priority of RF resource usage between GNSS and LTE.

Parameter

Priority ， integer type, sets the priority value between GNSS and LTE.

Correspondence of priority levels for GNSS/LTE on different platforms:

Priority BG95M1/M3
0 GNSS>LTE
1 LTE>GNSS

Return Value

0 - Successful execution

-1 - Failed execution

Get GNSS/LTE Priority

Currently, this function is only supported by BG95M1/M3 models.

quecgnss.getPriority 

quecgnss.getPriority()

On some modules, GNSS and LTE share RF resources. This interface is used to read the priority of RF resource usage between GNSS and LTE.

Return Value

Returns an integer representing the GNSS/LTE priority.

Correspondence of GNSS/LTE priority across different platforms:

Priority BG95M1/M3
0 GNSS>LTE
1 LTE>GNSS

Built-in GNSS Configuration Parameter Settings

Currently, this function is supported only by the EC800M GA/GB/GC/GD series, EG810M GA series, and ECX00U AA/LA series.

quecgnss.configSet 

quecgnss.configSet(config_type, config_value)

Sets GNSS parameters, including satellite system, NMEA sentence types, whether to use AGNSS, APFLASH, etc.

Parameter Description

  • config_type ，int，The types of GNSS configuration options to be set are as follows:
Value Description
0 Configure the satellite system to be used
1 Configure the types of NMEA sentences to output
2 Configure whether to enable AGPS
3 Configure whether to enable APFLASH
4 Configure whether to enable GNSS backup power
  • config_value ，int，The values of GNSS configuration options and their meanings are as follows:

Satellite System（config_type = 0）：

Value Description
0 GPS
1 GPS + BeiDou
3 GPS + GLONASS + Galileo
4 GPS + GLONASS
5 GPS + BeiDou + Galileo
6 GPS + Galileo
7 BeiDou

NMEA Sentence Types (config_type = 1): This field is represented as a bitmap. Options to be enabled should be set to 1.
For example, to output GGA + RMC + GSV + GSA + VTG, the bitmap should be 011111 , which corresponds to a decimal value of 31.

Value Description
0 Disable all (000000).
1 GGA(000001)
2 RMC(000010)
4 GSV(000100)
8 GSA(001000)
16 VTG(010000)
32 GLL(100000)
63 All outputs (111111).

Enable AGPS (config_type = 2): When enabled, GNSS will download ephemeris data from the network and attempt to use it at startup to accelerate positioning.

Value Description
0 Disable
1 Enable

Enable APFLASH (config_type = 3): When enabled, GNSS will store ephemeris data on the Quecpython module and attempt to use it at startup to accelerate positioning.

Value Description
0 Disable
1 Enable

Enable Backup Power (config_type = 4): When enabled and backup power is properly connected, the GNSS chip can autonomously store ephemeris data.

Backup power is supported on the EC800M GB/GD series.

Value Description
0 Disable
1 Enable

Return Value

int: 0 indicates success; any other value indicates failure.

Read Built-in GNSS Configuration Parameters

Currently, this function is supported only by the EC800M GA/GB/GC/GD series, EG810M GA series, and ECX00U AA/LA series.

quecgnss.configGet 

quecgnss.configGet(config_type)

Reads GNSS parameters, including satellite system, NMEA sentence types, whether AGNSS is used, APFLASH, etc.

Parameter Description

  • config_type ，int，The types of GNSS configuration options to be read are as follows：
Value Description
0 Configure the satellite system to be used
1 Configure the types of NMEA sentences to output
2 Configure whether to enable AGPS
3 Configure whether to enable APFLASH
4 Configure whether to enable GNSS backup power

Return Value

int，Meanings are as follows (–1 indicates failure).

Satellite System（config_type = 0）：

Value Description
0 GPS
1 GPS + BeiDou
3 GPS + GLONASS + Galileo
4 GPS + GLONASS
5 GPS + BeiDou + Galileo
6 GPS + Galileo
7 BeiDou

NMEA Sentence Types (config_type = 1): This field is represented as a bitmap. Options that are enabled are set to 1.
For example, if GGA + RMC + GSV + GSA + VTG are output, the returned value is 31, which corresponds to the bitmap 011111 in binary.

Value Description
0 Disable all (000000).
1 GGA(000001)
2 RMC(000010)
4 GSV(000100)
8 GSA(001000)
16 VTG(010000)
32 GLL(100000)
63 All outputs (111111).

Enable AGPS (config_type = 2): When enabled, GNSS will download ephemeris data from the network and attempt to use it at startup to accelerate positioning.

Value Description
0 Disable
1 Enable

Enable APFLASH (config_type = 3): When enabled, GNSS will store ephemeris data on the Quecpython module and attempt to use it at startup to accelerate positioning.

Value Description
0 Disable
1 Enable

Enable Backup Power (config_type = 4): When enabled and backup power is properly connected, the GNSS chip can autonomously store ephemeris data.

Backup power is supported on the EC800M GB/GD series.

Value Description
0 Disable
1 Enable