User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R08 Objective Specification System description
Page 65 of 188
 GNSS supply enable:
The GPIO2 is by default configured by AT+UGPIOC command to enable or disable the supply of the u-blox
GNSS receiver connected to the cellular module.
The GPIO1, GPIO3, GPIO4 pins and, on SARA-U2 series only, also the SIM_DET pin, can be configured to
provide the “GNSS supply enable” function, alternatively to the default GPIO2 pin, setting the parameter
<gpio_mode> of AT+UGPIOC command to 3. The “GNSS supply enable” mode can be provided only on
one pin per time: it is not possible to simultaneously set the same mode on another pin.
The pin configured to provide the “GNSS supply enable” function is set as
o High, to switch on the u-blox GNSS receiver, if AT+UGPS parameter <mode> is set to 1
o Low, to switch off the u-blox GNSS receiver, if AT+UGPS parameter <mode> is set to 0 (default)
 GNSS data ready:
Only the GPIO3 pin provides the “GNSS data ready” function, to sense when a u-blox GNSS receiver
connected to the cellular module is ready to send data via the DDC (I
2
C) interface, setting the parameter
<gpio_mode> of AT+UGPIOC command to 4.
The pin configured to provide the “GNSS data ready” function is set as
o Input, to sense the line status, waking up the cellular module from idle-mode when the u-blox
GNSS receiver is ready to send data via the DDC (I
2
C) interface, if the first AT+UGPS parameter is
set to 1 and the first AT+UGPRF parameter is set to 16
o Tri-state with an internal active pull-down enabled, otherwise (default setting)
 GNSS RTC sharing:
Only the GPIO4 pin provides the “GNSS RTC sharing” function, to provide an RTC (Real Time Clock)
synchronization signal to the u-blox GNSS receiver connected to the cellular module, setting the parameter
<gpio_mode> of AT+UGPIOC command to 5.
The pin configured to provide the “GNSS RTC sharing” function is set as
o Output, to provide an RTC (Real Time Clock) synchronization signal to the u-blox GNSS receiver if
the first AT+UGPS parameter is set to 1 and the first AT+UGPRF parameter is set to 32
o Low, otherwise (default setting)
 SIM card detection:
The SIM_DET pin of SARA-G3 modules is by default configured to detect SIM card mechanical presence and
this configuration cannot be changed by AT command.
The SIM_DET pin of SARA-U2 modules is by default configured to detect SIM card mechanical presence as
default setting of the AT+UGPIOC command: the “SIM card detection” function is enabled as the parameter
<gpio_mode> of AT+UGPIOC command is set to 7 (default setting).
The SIM_DET pin configured to provide the “SIM card detection” function is set as
o Input with an internal active pull-down enabled, to sense SIM card mechanical presence
The SIM_DET pin can sense the SIM card mechanical presence only if properly connected to the mechanical
switch of a SIM card holder as described in section 2.5:
o Low logic level at SIM_DET input pin is recognized as SIM card not present
o High logic level at SIM_DET input pin is recognized as SIM card present
SARA-U2 modules provide the additional function “SIM card hot insertion/removal” on the SIM_DET pin,
which can be enabled using the AT+UDCONF=50 command if the “SIM card detection” function is enabled
by AT+UGPIOC (for more details see u-blox AT Commands Manual [3]): in this case the SIM interface of the
SARA-U2 modules is disabled when a Low logic level is recognized at SIM_DET input pin (within 20 ms from
the start of the Low level) and it is enabled when an High logic level at SIM_DET input pin is recognized.
SARA-G3 series do not support the additional function “SIM card hot insertion/removal”