is:
AT^WPDFR=<number of positioning operations>, <time interval in secs>
The default value is 65535 attempts in 1 second intervals or
AT^WPDFR=65535, 1
.
Next we set the quality of service parameters on the modem with the
AT^WPQOS
command. The format of the command is:
AT^WPQOS=<time limit>,<horizontal accuracy>
The
<time limit>
setting is the amount of time the unit will spend searching for the
satellite. We recommend setting the default value at 255 seconds to give the unit the
maximum time to search. The <horizontal accuracy> parameter is the accuracy of the
reading in meters. The range is from 25 meters to 1000 meters. Setting a higher value
allows the modem to lock onto a satellite quicker. Generally, setting a higher value will
not significantly affect the accuracy of your positioning but will allow faster reporting.
Now we enter
AT^WPDGP
to start the positioning. The modem will now begin
searching for satellites. Once it locates the modem’s position, it will report it as follows:
^POSITION
-71.09762d,
42.34636d,52m
The first value is the longitude, with positive values representing east of Greenwich UK
and negative values representing west. The second value is latitude, with positive
values representing north of the equator and negative values representing south. The
last value is the altitude expressed in meters above sea level.
If the modem has not locked onto its position when the <time limit> parameter of the
^WPQOS
command has expired it will report:
^POSEND: 12,65534
Where
12
is the reason (timeout in this example), and 65534 is the number of attempts
left.
To end your GPS session, enter the command
AT^WPEND
.
For more information about the commands used in this section please see both the
Huawei AT command manual, and the Huawei Application guide. These documents are
available at
www.zoomtel.com/4575support
.
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