SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
System description
Page 44 of 217
1.7.2
Antenna detection interface (ANT_DET)
Antenna detection interface (
ANT_DET
) is not supported by SARA-G300 and SARA-G310 modules.
The antenna detection is based on ADC measurement. The
ANT_DET
pin is an Analog to Digital Converter
(ADC) provided to sense the antenna presence.
The antenna detection function provided by
ANT_DET
pin is an optional feature that can be implemented if the
application requires it. The antenna detection is forced by the +UANTR AT command. See the
u-blox AT
Commands Manual
[3] for more details on this feature.
The
ANT_DET
pin generates a DC current (20 µA for 5.4 ms on SARA-G340 / SARA-G350, 10 µA for 128 µs on
SARA-U2 modules) and measures the resulting DC voltage, thus determining the resistance from the antenna
connector provided on the application board to GND. So, the requirements to achieve antenna detection
functionality are the following:
an RF antenna assembly with a built-in resistor (diagnostic circuit) must be used
an antenna detection circuit must be implemented on the application board
See section 2.4.2 for design-in guidelines for antenna detection circuits on an application board and diagnostic
circuits on an antenna assembly.
1.8
SIM interface
1.8.1
(U)SIM card interface
SARA-G3 and SARA-U2 series modules provide a high-speed SIM/ME interface, including automatic detection
and configuration of the voltage required by the connected (U)SIM card or chip.
Both 1.8 V and 3 V SIM types are supported: activation and deactivation with automatic voltage switch from
1.8 V to 3 V is implemented, according to ISO-IEC 7816-3 specifications. The
VSIM
supply output pin provides
internal short circuit protection to limit start-up current and protect the device in short circuit situations.
The SIM driver supports the PPS (Protocol and Parameter Selection) procedure for baud-rate selection, according
to the values determined by the SIM Card.
The SIM Application Toolkit is supported by all SARA-G3 and SARA-U2 series except SARA-G300 and
SARA-G310.
1.8.2
SIM card detection interface (SIM_DET)
Not supported by SARA-G300-00S and SARA-G310-00S modules.
The
SIM_DET
pin is configured as an external interrupt to detect the SIM card mechanical / physical presence.
The pin is configured as input with an internal active pull-down enabled, and it can sense SIM card presence only
if properly connected to the mechanical switch of a SIM card holder as described in section 2.5:
Low logic level at
SIM_DET
input pin is recognized as SIM card not present
High logic level at
SIM_DET
input pin is recognized as SIM card present
The SIM card detection function provided by
SIM_DET
pin is an optional feature that can be implemented / used
or not according to the application requirements: an Unsolicited Result Code (URC) can be generated each time
that there is a change of status (for more details, see the “simind” value of the <descr> parameter of +CIND and
+CMER commands in the
u-blox AT Commands Manual
[3]).
The optional function “SIM card hot insertion/removal” can be additionally enabled on the SARA-U2 modules’
SIM_DET
pin by AT commands (see the section 1.11 and the
u-blox AT Commands Manual
[3], +UGPIOC,
+UDCONF=50).
