Data Sheet

Table Of Contents
SARA-R4/N4 series - Data Sheet
UBX-16024152 - R16 Interfaces Page 11 of 39
2.3.2 Module power-off
SARA-R4/N4 series can be properly switched off, with storage of the current parameter settings and
a clean network detach, in one of these ways:
AT+CPWROFF command (see the SARA-R4/N4 series AT Commands Manual [1])
Low pulse on the PWR_ON pin for a valid time period (see section 4.2.8)
An abrupt shutdown occurs on SARA-R4/N4 series modules, without storage of the current
parameter settings and without a clean network detach, when:
the VCC supply drops below the extended operating range minimum limit
a low level is applied on the RESET_N pin, which is normally set high by an internal pull-up, for a
valid time period (see section 4.2.9). RESET_N line has to be driven by open drain, open collector or
contact switch.
2.3.3 Module reset
SARA-R4/N4 series modules can be reset (re-booted) by:
AT+CFUN command (see the SARA-R4/N4 series AT Commands Manual [1]). This causes an
“internal” or “software” reset of the module. The current parameter settings are saved in the
module’s non-volatile memory and a clean network detach is performed.
2.4 SIM
2.4.1 SIM interface
A SIM card interface is provided on VSIM, SIM_IO, SIM_CLK, SIM_RST pins: the high-speed SIM/ME
interface is implemented as well as the automatic detection of the required SIM supporting voltage.
Both 1.8 V and 3 V SIM types are supported (1.8 V and 3 V). Activation and deactivation with an
automatic voltage switch from 1.8 V to 3 V is implemented according to the ISO-IEC 7816-3
specifications. The SIM driver supports the PPS procedure for baud-rate selection, according to the
values proposed by the SIM card/chip.
2.4.2 SIM detection
The GPIO5 pin of SARA-R4/N4 series modules is a 1.8 V digital input which can be configured as an
external interrupt to detect the SIM card presence, as intended to be properly connected to the
mechanical switch of an external SIM card holder. For more details, see the SARA-R4/N4 series
System Integration Manual [2] and the SARA-R4/N4 series AT Commands Manual [1].
2.5 Serial communication
The SARA-R4/N4 series provides the following serial communication interfaces:
UART interface: asynchronous serial interface available for the communication with a DTE host
application processor (AT commands, data communication, FW update by means of FOAT)
USB interface: High-Speed USB 2.0 compliant interface available for communications with a USB
host application processor (AT commands, data communication, FW update by means of the
FOAT feature), for FW update by means of the u-blox tool and for diagnostics
SPI interface: Serial Peripheral Interface available for communications with an external compatible
device
SDIO interface: Secure Digital Input Output interface available for communications with a
compatible device
DDC interface: I
2
C bus compatible interface available for communications with external I
2
C devices