4112221
Rev 7.2
June 19, 2013
32
User Guide
Interfaces
Figure 15. Equivalent circuit of V
OL
,
Vref
> 2.8V
Figure 16. Equivalent circuit of V
OH
,
Vref
> 2.8V
The GPIO pin is mainly used to:
Act as a switch for a
transistor when the GPIO is configured as output.
Act as a status reading when the GPIO is configured as input.
The GPIOs may be controlled with the following AT commands:
AT+WIOW
for write access to the GPIO value, when the GPIO is used as an output
AT+WIOR
for read access to the GPIO value, when the GPIO is used as an input
By default, and when the FX Series has been reset, both GPIOs are configured as inputs. The AT
command
AT+WIOM
must be used to change this configuration. Refer to documents [1] Open AT
Application Framework AT Commands Interface Guide and [2] AirPrime SL808xT and Q2698 Open
AT Framework Commands Interface Guide for more information regarding this AT command.
5.1.1.1.1.
Setting the GPIO as an Output
Refer to the following example for how to configure the GPIO as an output.
Enter the following commands:
AT+WIOM=1,“GPIO21”,1,0
this command activates GPIO21 as an
output and sets it at a low level.
AT+WIOW=“GPIO21”,1
this command sets the output level of
GPIO21 to HIGH.
