LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi Dist., New Taipei City 221, Taiwan
℡
886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Page
13/23
© 2018 LOCOSYS Technology Inc.
VTG---Course Over Ground and Ground Speed
Table 8.1-10 contains the values for the following example:
$GPVTG,79.65,T,,M,2.69,N,5.0,K,A*38
Table 8.1-10
VTG Data Format
Name
Example
Units
Description
Message ID
$GPVTG
VTG protocol header, GN means GPS+GLONASS
GP means GPS only
GL means GLONASS only
Course over ground
79.65
degrees
Measured heading
Reference
T
True
Course over ground
degrees
Measured heading (Not shown)
Reference
M
Magnetic (Not shown)
Speed over ground
2.69
knots
Measured speed
Units
N
Knots
Speed over ground
5.0
km/hr
Measured speed
Units
K
Kilometer per hour
Mode
A
A=autonomous, D=DGPS, E=DR, N=Data not valid,
R=Coarse Position, S=Simulator
Checksum
*38
<CR> <LF>
End of message termination
8.2
Proprietary NMEA input/output message
Please refer to MTK proprietary message.
8.3
Examples to configure the power mode of GNSS module
The GNSS module supports different power modes that user can configure by issuing
software commands.
8.3.1
Standby mode
User can issue software command to make GNSS module go into standby mode that
consumes less than 200uA current. GNSS module will be awaked when receiving any byte.
The following flow chart is an example to make GNSS module go into standby mode and
then wake up.
