Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!1.eu.feeder.erje.net!weretis.net!feeder4.news.weretis.net!feeds.phibee-telecom.net!newsfeed.xs4all.nl!newsfeed7.news.xs4all.nl!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail
Return-Path: <torriem+gmail@torriefamily.org>
X-Original-To: python-list@python.org
Delivered-To: python-list@mail.python.org
X-Spam-Status: OK 0.097
X-Spam-Evidence: '*H*': 0.81; '*S*': 0.00; 'benjamin': 0.09; 'expected,': 0.16; 'from:addr:torriem': 0.16; 'from:name:michael torrie': 0.16; 'true:': 0.16; 'wrote:': 0.16; '(in': 0.18; 'header :In-Reply-To:1': 0.24; 'second': 0.24; 'testing': 0.25; 'header :User-Agent:1': 0.26; 'command': 0.28; 'actual': 0.29; 'prints': 0.29; 'guess': 0.29; 'push': 0.31; 'code': 0.31; 'run': 0.32; 'probably': 0.32; 'curious': 0.33; 'add': 0.34; 'message- id:@gmail.com': 0.35; 'to:addr:python-list': 0.35; "isn't": 0.35; 'there': 0.36; 'subject:: ': 0.37; 'skip:g 20': 0.37; 'received:org': 0.38; 'button': 0.38; 'pm,': 0.39; 'expect': 0.39; 'to:addr:python.org': 0.39; 'received:192': 0.39; 'some': 0.40; 'your': 0.60; 'times': 0.61; 'here': 0.66; 'case?': 0.84; 'oscar': 0.84; 'bounce': 0.91
X-Virus-Scanned: amavisd-new at torriefamily.org
Date: Thu, 18 Jun 2015 16:42:14 -0600
From: Michael Torrie <torriem@gmail.com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
MIME-Version: 1.0
To: python-list@python.org
Subject: Re: Keypress Input
References: <rBHbx.75089$MO7.40532@fx10.iad> <Ojtfx.178941$Jv.137884@fx26.iad> <mailman.519.1434474965.13271.python-list@python.org> <Cl%fx.2$WK.0@fx07.iad> <mlq25a$188$1@reader1.panix.com> <5580CBC6.3000402@gmail.com> <CAHVvXxSH5fd2vMLYe4JXD6+jfQDfNjEnVuT_zdKtOZuDx70HLQ@mail.gmail.com>
In-Reply-To: <CAHVvXxSH5fd2vMLYe4JXD6+jfQDfNjEnVuT_zdKtOZuDx70HLQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
X-BeenThere: python-list@python.org
X-Mailman-Version: 2.1.20+
Precedence: list
List-Id: General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe: <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive: <http://mail.python.org/pipermail/python-list/>
List-Post: <mailto:python-list@python.org>
List-Help: <mailto:python-list-request@python.org?subject=help>
List-Subscribe: <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups: comp.lang.python
Message-ID: <mailman.617.1434667341.13271.python-list@python.org>
Lines: 24
NNTP-Posting-Host: 2001:888:2000:d::a6
X-Trace: 1434667341 news.xs4all.nl 2843 [2001:888:2000:d::a6]:39545
X-Complaints-To: abuse@xs4all.nl
Xref: csiph.com comp.lang.python:92858

On 06/18/2015 01:35 PM, Oscar Benjamin wrote:
> I use the following. I found in testing that when you push the button it
> prints 'Button pressed' 10 times a second (in actual use it calls poweroff
> so I guess bounce isn't an issue there). Is there some reason it needs to
> be cleverer in this case?

Yes, that would be expected, given your code has a while loop that never
exits.  Just curious what you expect the code to do that it's not doing.

You are probably right that debouncing isn't important in your
application.  So just add your poweroff command after the print()
statement, and break out of the loop:

...
while True:
    time.sleep(0.1)
    if not GPIO.input(PIN_NUM):
        print('Button pressed')
        # run shutdown command here
        os.system('/usr/sbin/shutdown')
        break