your position is our focus
3.0V
to
3.6V,
which
differs
slightly
from
the
ion
for
VCC
.
4.4.3 UBX Binary Protocol
T
u-blox
use
-blox
propri
tr
to
a
hos
using
asynchron
po
This
proprietary
e
res:
•
Compa
data
sed
•
Checksum
using
a
low-overhead
hm
•
odu
e
M
age
Identifier
ss-
and
Messag
Note
fer
greater
flexibility
and
more
p
M
s
to
communicate
with
u-center
AE
software
to
get
the
best
performance
and
optimal
two-stage
I/O
message
and
protocol
selection
procedure
for
the
available
serial
ports.
1.
The
RTCM,
NMEA
or
UBX
protocol
can
be
enabled
or
disabled
for
a
given
USART
port.
can
be
enabled
or
disabled
for
each
enabled
protocol
on
each
port.
4.4.3.1
UBX Packet Structure
A
basic
UBX
packet
looks
as
follows:
Note
The
voltage
range
for
VDDUSB
is
specified
from
specificat
he
GPS
Receivers
a
u
etary
protocol
to
protocol
has
th
ansmit
GPS
data
t
computer
ous
RS232
or
USB
rts.
following
key
featu
ct.
8
Bit
binary
protected,
is
u
checksum
algorit
M
lar,
using
a
2-stag
ess
(Cla
e
ID)
UBX
protocol
of
optimized
s
a
owerful
messages
than
N EA
protocol.
It’
debugging.
The
ANTARIS
®
4
receiver
features
a
2.
Messages
For
further
information
please
refer
to
ANTARIS
®
4
GPS Protocol Specifications [9].
Figure 70: UBX Protocol Framing
•
Every
message
starts
•
A
1
Byte
Class
Field
follows.
•
with
2
Bytes:
0xB5
0x62
The
Class
defines
the
basic
subset
of
the
message
A
1
Byte
ID
Field
defines
the
message
that
is
to
follow
It
does
not
include
Sync
Chars,
Length
Field,
Class,
ID
or
CRC
fields.
The
number
format
of
the
length
field
is
an
unsigned
16-Bit
integer
in
Little
Endian
Format.
•
The
Payload
is
a
variable
length
field.
•
CK_A
and
CK_B
is
a
16
Bit
checksum
whose
calculation
is
defined
below.
•
A
2
Byte
Length
Field
is
following.
Length
is
defined
as
being
the
length
of
the
payload,
only.
GPS
Modules
-
System
Integration
Manual
(SIM)
(incl.
Reference
Design)
Receiver
Description
GPS.G4-MS4-05007-A1
Page 82
