Telit Wireless Solutions UC864 manual Using a Gpio Pad as Input, Using a Gpio Pad as Output

UC864-E Hardware User Guide

1vv0300766a Rev.1 - 31/01/08

11.2 Using a GPIO Pad 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 2.6V CMOS levels of the GPIO.

NOTE: If the digital output of the device to be connected with the GPIO input pad has interface levels different from the 2.6V CMOS, it can be buffered with an open collector transistor, provided a 47KΩ pull-up resistor is connected as seen in the paragraph 0

11.3 Using a GPIO Pad as OUTPUT

The GPIO pads, when used as outputs, can drive 2.6V 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.

11.4 Using the Alarm Output GPIO6

The GPIO6 pad, when configured as Alarm Output, is controlled by the UC864-E module and will rise when the alarm starts and fall after the issue of a dedicated AT command.

This output can be used to power up the UC864-E controlling microcontroller or application at the alarm time, giving you the possibility to program a timely system wake-up to achieve some periodic actions and completely turn off either the application and the UC864-E during sleep periods, dramatically reducing the sleep consumption to few μA.

In battery-powered devices this feature will greatly improve the autonomy of the device.

NOTE: During RESET the line is set to HIGH logic level.

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