User's Manual

SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R08 Objective Specification System description
Page 64 of 188
1.11 General Purpose Input/Output (GPIO)
SARA-G300 and SARA-G310 modules do not support GPIOs.
SARA-G340, SARA-G350 and SARA-U2 modules provide pins which can be configured as general purpose input
or output, or can be configured to provide special functions via u-blox AT commands (for further details refer to
the u-blox AT Commands Manual [3], +UGPIOC, +UGPIOR, +UGPIOW, +UGPS, +UGPRF):
 SARA-G340 and SARA-G350 modules provide 4 configurable GPIO pins: GPIO1, GPIO2, GPIO3, GPIO4
 SARA-U2 modules provide 9 configurable GPIO pins: GPIO1, GPIO2, GPIO3, GPIO4, I2S_RXD, I2S_TXD,
I2S_CLK, I2S_WA, SIM_DET
The following functions are available:
 Network status indication:
The GPIO1, or the GPIO2, GPIO3, GPIO4 and, on SARA-U2 series only, the SIM_DET, alternatively from
their default settings, can be configured to indicate network status (i.e. no service, registered home network,
registered visitor network, voice or data call enabled), setting the parameter <gpio_mode> of AT+UGPIOC
command to 2.
No GPIO pin is by default configured to provide the “Network status indication” function.
The “Network status indication” 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 “Network status indication” function is set as
o Continuous Low,
if no service (no network coverage or not registered)
o Cyclically High for 100 ms, Low for 2 s,
if registered home 2G network
o Cyclically High for 50 ms, Low for 50 ms, High for 50 ms, Low for 2 s,
if registered home 3G network
o Cyclically High for 100 ms, Low for 100 ms, High for 100 ms, Low for 2 s,
if registered visitor 2G network (roaming)
o Cyclically High for 50 ms, Low for 50 ms, High for 50 ms, Low for 100 ms,
if registered visitor 3G network (roaming)
o Continuous High,
if voice or data 2G/3G call enabled
 GSM Tx burst indication:
GPIO1 pin can be configured by AT+UGPIOC to indicate when a GSM Tx burst/slot occurs, setting the
parameter <gpio_mode> of AT+UGPIOC command to 9.
No GPIO pin is by default configured to provide the “GSM Tx burst indication” function.
The pin configured to provide the “GSM Tx burst indication” function is set as
o High, since ~10 µs before the start of first Tx slot, until ~5 µs after the end of last Tx slot
o Low, otherwise
SARA-U280 and SARA-U290 modules do not support the “GSM Tx burst indication” function on GPIO1,
as the modules do not support 2G radio access technology.