Micro Tracker Reference Guide FW 1.7 V1.1
Page 27 of 39
11th october 2018
Restricted distribution
5.5.1
GPS fix payload
Common header
Data
Byte 0-4
Byte 5
Byte 6-8
Byte 9-11
Byte 12
Byte 13-15
Header
Age
Latitude
Longitude
EHPE
Encrypted
Age
: Age of the fix. Encoded form using
lo
= 0,
hi
= 2040,
nbits
= 8,
nresv
= 0. Expressed in seconds. The step is
8 seconds.
Latitude
: Latitude of the position (expressed in degree) calculated as follow:
Latitude = Latitude << 8
If Latitude > 0x7FFFFFFF then Latitude = Latitude
–
0x100000000
Latitude = Latitude / 10
7
Longitude
: Longitude of the position (expressed in degree) calculated as follow:
Longitude = Longitude << 8
If Longitude > 0x7FFFFFFF then Longitude = Longitude
–
0x100000000
Longitude = Longitude / 10
7
EHPE
: Estimated Horizontal Position Error, expressed in meters. Encoded form using
lo
= 0,
hi
= 1000,
nbits
=
8,
nresv
= 0. The step is 5.9 meters.
Encoded form is detailed in the
Encoded form
section.
5.5.2
GPS timeout payload
Common header
Data
Byte 0-4
Byte 5
Byte 6
Byte 7
Byte 8
Byte 9
Header
Cause
C/N 0
C/N 1
C/N 2
C/N 3
Cause
: Timeout cause
➢
0 - User timeout cause
C/N 0
: Carrier over noise (dBm) for the first satellite seen.
C/N 1
: Carrier over noise (dBm) for the second satellite seen.
C/N 2
: Carrier over noise (dBm) for the third satellite seen.
C/N 3
: Carrier over noise (dBm) for the fourth satellite seen.
Notes:
1-
C/N
encoding uses:
lo
= 0,
hi
=2040,
nbits
=8,
nresv
= 0. It is expressed in dBm with a step of 0,2dBm
2-
Encoded form is detailed in the
Encoded form
section.
5.5.3
WIFI timeout payload
Common header
Data
Byte 0-4
Byte 5
Byte 6
Byte 7
Byte 8
Byte 9
Byte 10
Header
v_bat1
v_bat2
v_bat3
v_bat4
v_bat5
v_bat6
v_bat1
: encoded voltage at the start time (T0) of the WIFI scan.
v_bat2
: encoded voltage at T0 + 0.5 second.
v_bat3
: encoded voltage at T0 + 1 second.
v_bat4
: encoded voltage at T0 + 1.5 second.