User's Manual

LISA-U1/LISA-H1 series - System Integration Manual
3G.G2-HW-10002-2 Advance Information System description
Page 74 of 116
1.12 General Purpose Input/Output (GPIO)
The LISA-U1/LISA-H1 series modules provide 5 pins (GPIO1, GPIO2, GPIO3, GPIO4 and GPIO5) 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 u-blox AT Commands Manual [2], +UGPIOC, +UGPIOR, +UGPIOW,
+UGPS, +UGPRF).
The available functions are described below:
 GSM Tx burst indication: the GPIO1 can be configured by AT+UGPIOC to indicate when a GSM Tx
burst/slot occurs. The pin can be connected on the application board to an input pin of an application
processor to indicate when a GSM Tx burst/slot occurs
 GPS supply enable: the GPIO2 is by default configured to enable or disable the supply of the u-blox GPS
receiver connected to the LISA-U1/LISA-H1 series module. The pin must be connected to the active-high
enable pin (or the active-low shutdown pin) of the voltage regulator that supplies the u-blox GPS receiver on
the application board. The pin is automatically set output high to switch on the u-blox GPS receiver when
the parameter <mode> of +UGPS AT command is set to 1, and otherwise it is set in tri-state with an internal
active pull-down enabled. The GPIO1, GPIO3, GPIO4 or GPIO5 can be configured by AT+UGPIOC to
provide this feature, alternatively to the default GPIO2
 GPS data ready: the GPIO3 is by default configured to sense when the u-blox GPS receiver connected to
the LISA-U1/LISA-H1 series module is ready to send data by the DDC (I
2
C) interface. The pin must be
connected to the data ready output of the u-blox GPS receiver (i.e. the pin TxD1 of the u-blox GPS module)
on the application board. The pin automatically senses the line status to wake up the LISA-U1/LISA-H1 series
module from idle mode if the u-blox GPS receiver is ready to send data by the DDC (I
2
C) interface, when the
parameter <mode> of +UGPS AT command is set to 1, and otherwise it is set in tri-state with an internal
active pull-down enabled
 GPS aiding synch: the GPIO4 is by default configured to provide a synchronization timing signal to the
u-blox GPS receiver connected to the LISA-U1/LISA-H1 series module. The pin must be connected to the
synchronization timing input of the u-blox GPS receiver (i.e. the pin EXTINT0 of the u-blox GPS module) on
the application board. The pin automatically provides a synchronization timing signal to the u-blox GPS
receiver when the parameter <mode> of +UGPS AT command is set to 1, and otherwise it is set in tri-state
with an internal active pull-down enabled
 SIM card detection: the GPIO5 is by default configured to detect SIM card presence. The pin must be
connected on the application board to the SW2 pin of the SIM card connector with a 470 kΩ pull-down
resistor and SW1 pin of the SIM card connector must be pulled up to the module V_INT by a 1 kΩ pull-up
resistor
 Network status indication: each GPIO (GPIO1, GPIO2, GPIO3, GPIO4 or GPIO5) can be configured by
AT+UGPIOC to indicate network status (registered home network, registered roaming, data transmission, no
service). The pin configured to provide this feature can be connected on the application board to an input
pin of an application processor or can drive a LED by a transistor with integrated resistors to indicate
network status
 General purpose input: all the GPIOs (GPIO1, GPIO2, GPIO3, GPIO4 and GPIO5) can be configured by
AT+UGPIOC as input, sensing high or low digital level by AT+UGPIOR
 General purpose output: all the GPIOs (GPIO1, GPIO2, GPIO3, GPIO4 and GPIO5) can be configured by
AT+UGPIOC as output, set in the high or low digital level by AT+UGPIOW, sensing high or low digital level
by AT+UGPIOR
 Pad disabled: all the GPIOs (GPIO1, GPIO2, GPIO3, GPIO4 and GPIO5) can be configured by AT+UGPIOC
in tri-state, with an internal active pull-down enabled