Gtop
Binary Protocol Customization Service
Binary protocol is an efficient way of
transferring coordinate messages from GPS module to micro controllers.
Coordinates
that used to require more than 20 bytes in NMEA can now be sent with
only 8
bytes in binary protocol format. In addition, because of the increase in
efficiency, a lower transfer rate can easily parse 10Hz messages without
losing
any packages.
Binary protocol is a lot more efficient
when using tiny 8-bit micro controllers. This is because
microcontrollers
contain limited flash space, and the process of converting ASCII string
into
normal variables will require huge libraries and a lot of CPU
calculation
cycles, which may be too much to handle for these tiny controllers. With
binary
protocol, these simple bytes can be put directly into the variables with
a few
clock cycles, without the need for parsing, conversion and the huge C++
string
libraries.
1.
Service Description
Customization of output
sentences in binary protocol
format shown in the tables below.
2.
Requirement
Output Binary
sentence has to be converted from “Gtop One Sentence Format”. See “One
Sentence” software technology for more details.
3.
Supported Data Format Conversion
From: PGTOP “Gtop One Sentence Format”
$PGTOP, 064951.000,2307.1256,N,12016.4438,E,
A,0.03,165.480.03,N,0.06,K
* checksum
Customize Data Format for NMEA protocol One Sentence
Table.1 |
|||
Name |
Example |
Units |
Desciption |
UTC Time |
064951.000 |
|
hhmmss.sss |
Latitude |
2307.1256 |
|
ddmm.mmmm |
N/S Indicator |
N |
|
N=north or S=south |
Longitude |
12016.4438 |
|
ddmm.mmmm |
E/W Indicator |
E |
|
E=east or W=west |
Status |
A |
|
A=data valid or
V=data not valid |
Speed over Ground |
0.03 |
Knots |
|
Course over Ground |
165.48 |
Degrees |
True |
Speed |
0.03 |
Knots |
Masured horizontal speed |
Units |
N |
|
Knots |
Speed |
0.06 |
Km/hr |
Measured horizontal
speed |
Units |
K |
|
Kiloneters per hour |
To: Gtop
Binary protocol format
0x04,0x24,0x03,0xEA,0x94,0x28,0x01,0x60,0x74,0xF4,0x01,0x07,0x2B,0x64,0xD4,0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x50,0x4E,0X00,0X00,0X00,
0x95,0x4B,0xE9,0x0D,0x
Customize Data Format for
Binary protocol
Table.2 |
|||
Name |
Example |
Units |
Description |
Preamble |
0x04,0x24 |
2bytes |
Header,
always the same |
UTC
Time |
0x03 0xDF 0x12 0xD8 |
4 bytes Hi byte to Low byte |
UTC Time(hhmmss.sss) The original
value will be converted Example:064951.000*(10^3)=64951000 |
Latitude |
0x01 0x60 0x74 0xCC |
4 bytes Hi byte to Low byte |
Latitude (in
decimal degrees) The original
value will be converted Example:23.098572*(10^6)=23098572 |
N/S Indicator |
0x01 |
1byte |
0x01=>North or 0x02 =>South |
Longitude |
0x07 0x2B 0x64 0xDF |
4 bytes Hi byte to Low byte |
Longitude (in
decimal degrees) The original
value will be converted Example:120.284383*(10^6)=120284383 |
E/W Indicator |
0x01 |
1byte |
0x01=>East
or 0x02 =>West |
Status |
0x01 |
1byte |
0x01
=>data valid or 0x02 =>data not valid |
Course
over ground |
0x07 0x56 0xB7 0x00 |
4 bytes Hi byte to Low byte |
Course over
ground(in degree) The original
value will be converted Example:123.123456=>123.123456*1000000=123123456(degrees) |
Speed
over ground |
0x00 0x00 0x00 0x24 |
4 bytes Hi byte to Low byte |
Ground
Speed(knot/hr) The original
value will be converted Example:0.036(knot/hr)=>0.036*1000=36 |
Units(Knots) |
0x4E |
1byte |
Unit of
Speed. Example:0x4E=’N’ |
Speed
over ground |
0x00 0x00 0x00 0x40 |
4 bytes Hi byte to Low byte |
Ground
Speed(km/hr) The original
value will be converted Example:0.067(km/hr)=>0.067*1000=67 |
Units(Kilometer) |
0x4B |
1byte |
Unit of
Speed. Example:0x4B=’K’ |
Checksum |
0x47 |
1byte |
Checksum.
Refer to Note.1 |
End
Word |
0x0D 0x |
2bytes |
End word,
always the same |
Note.1
1. The checksum will be
calculated by X or all
bytes (except for the preamble bytes and end word )
For(I=0;I<N;I++)
{
Checksum = Checksum ^ Buffer[I]
}
Available Models
“Gtop
Binary Protocol” is supported on all GlobalTop
GPS
modules with MT3318 or MT3329
chipset. If you are interested in implementing this exciting technology
into
your device, contact us (sales@gtop-tech.com)
right now for further information.