Data Sheet

GPS Module
L80 GPS Protocol Specification
L80_GPS_Protocol_Specification Confidential / Released 16 / 41
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.
Table 2: Structure of MTK NMEA packet
Filed
Length(bytes)
Description
$
1
Each NMEA message starts with ‘$’
Talker ID
1
‘P’ for proprietary message
NMEA data type
3
Always ‘MTK’ to indicate MTK proprietary message
Data Filed
Packet
type
3
Packet type, from ‘000’ to ‘999’
Packet
data
Variable, depend
on the packet type
Data fields, delimited by comma ‘,’
*
1
End character of data field
Checksum
2
A hexadecimal number calculated by exclusive OR of
all characters between ‘$’ and ‘*’
<CR><LF>
2
Each NMEA message ends with ‘CR’ and ‘LF’
3.1. Packet Type: 010 PMTK_SYS_MSG
This message is used to automatically output system messages by GPS module.
Example:
$PMTK010,001*2E<CR><LF>
Field
Description
$
Each NMEA message starts with ‘$’
Quectel
Confidential