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NL865H2 Hardware Design Guide
1VV0301616 Rev. 7
Page
41
of
67
2020-04-20
NOTE:
The internal GPIO’s pull up/pull down could be set to the preferred
status for the application using the AT#GPIO command.
Please refer for the AT Commands User Guide for the detailed
command Syntax.
5.3.1.
Using a GPIO as INPUT
The GPIO pads, when used as inputs, can be connected to a digital output of another
device and report its status, provided this device has interface levels compatible with the
1.8V CMOS levels of the GPIO. If the digital output of the device to be connected with the
GPIO input pad has interface levels different from the 1.8V CMOS, then it can be buffered
with an open collector transistor with a 47K pull up to VAUX.
NOTE:
In order to avoid a back powering effect it is recommended to avoid having
any HIGH logic level signal applied to the digital pins of the NL865H2-W1
when the module is powered off or during a reboot transition.
The VAUX pin can be used for input pull up reference or/and for ON
monitoring.
5.3.2.
Using a GPIO as OUTPUT
The GPIO pads, when used as outputs, can drive 1.8V CMOS digital devices or
compatible hardware. When set as outputs, the pads have a push-pull output and
therefore the pull-up resistor may be omitted.