User's Manual

GE864- QUAD Har dwar e User Guide

1vv0300872 Rev.1 2010-04-02

12.7. Using the Buzzer Output GPIO7

Alternate Function

, the GPIO7 is controlled by the firmware that depends on the

function implemented internally.

This setup places always the GPIO7 pin in

OUTPUT

dir ection and the corresponding

function must be activated properly by AT# SRP command (refer to

AT commands

specification

Also in this case, the

dummy value

for the pin state can be both “

” or “

”.

Send the command AT# GPIO=7, 1, 2<cr>:

Wait for response OK

Send the command AT# SRP=3

The GPIO7 pin will be set as

Alternate Function

pin with its dummy logic status set to

HIGH

value.

The "

Alter nate function

” permits your application to easily implement

Buzzer

featur e

with some small har dware extension of your application as shown in the

sample figure below.

Example of Buzzer

’

s driving cir cuit

NOTE:

To cor r ectly drive a buzzer, a driver must be provided; its characteristics depend on

the Buzzer and for them refer to your buzzer vendor .

TR1

BCR141W

TR2

SMBT2907A

4,7K

D1N4148

33pF

+V buzzer

GPIO7