Smart Machine Smart Decision
SIM5320JE-TE_Hardware Design_V1.01
2012-07-10
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required to calculate the handset’s position. Therefore, rather than provide the GPS measurements and
available network data back to the location server, the mobile calculates the location on the handset and
passes the result to the requesting entity.
In standalone (autonomous) mode, the handset demodulates the data directly from the GPS satellites.
This mode has some reduced cold-start sensitivity, and a longer time to first fix as compared to the assisted
modes. However, it requires no server interaction and works out of network coverage.
This combination of GPS measurements and available network information provides:
●
High-sensitivity solution that works in all terrains: Indoor, outdoor, urban, and rural
●
High availability that is enabled by using both satellite and network information
Therefore, while network solutions typically perform poorly in rural areas and areas of poor cell
geometry/density, and while unassisted, GPS-only solutions typically perform poorly indoors. The
SIM5320JE-TE GPS solution provides optimal time to fix, accuracy, sensitivity, availability, and reduced
network utilization in both of these environments, depending on the given condition.
3.12.3
Application Guide
Users can adopt an active antenna or a passive antenna as GPS signal transceiver.
In active antenna circuit, SIM5320JE-TE provides DC 2.6V (VREG_AUX) for active antenna.
GPS can be used by NMEA port. User can select NMEA as output through UART or USB. NMEA
sentences are automatic and no command is provided. NMEA sentences include GSV, GGA, RMC, GSA,
and VTG. Before using GPS, user should configure SIM5320JE-TE in proper operating mode by AT
command. Please refer to related document for details. SIM5320JE-TE can also get position location
information through AT directly.
Note:GPS is closed by default, it could be started by AT+CGPS. The AT command has two parameters, the first is on/off,
and the second is GPS mode. Default mode is standalone mode.
AGPS mode needs more support from the mobile telecommunication network. Refer to AGPS application document for
details.
3.13
Multi-functional interface
SIM5320JE-TE merges functions for various applications. It can enrich users’ design and lower the cost of
users’ hardware.
3.13.1
Sink Current Source
The dedicated pin (CURRENT_SINK) is intended for driving passive devices
，
such as LCD backlight, this
implementation is +5V tolerant and suitable for driving white LEDs. The high-current driver can maintain
a constant current which is set by
the AT command “AT+ CLEDITST”
, capable of up to 150 mA.
